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Gopal A, Yan L, Kashif S, Munshi T, Roy VAL, Voelcker NH, Chen X. Biosensors and Point-of-Care Devices for Bacterial Detection: Rapid Diagnostics Informing Antibiotic Therapy. Adv Healthc Mater 2022; 11:e2101546. [PMID: 34850601 DOI: 10.1002/adhm.202101546] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/20/2021] [Indexed: 02/06/2023]
Abstract
With an exponential rise in antimicrobial resistance and stagnant antibiotic development pipeline, there is, more than ever, a crucial need to optimize current infection therapy approaches. One of the most important stages in this process requires rapid and effective identification of pathogenic bacteria responsible for diseases. Current gold standard techniques of bacterial detection include culture methods, polymerase chain reactions, and immunoassays. However, their use is fraught with downsides with high turnaround time and low accuracy being the most prominent. This imposes great limitations on their eventual application as point-of-care devices. Over time, innovative detection techniques have been proposed and developed to curb these drawbacks. In this review, a systematic summary of a range of biosensing platforms is provided with a strong focus on technologies conferring high detection sensitivity and specificity. A thorough analysis is performed and the benefits and drawbacks of each type of biosensor are highlighted, the factors influencing their potential as point-of-care devices are discussed, and the authors' insights for their translation from proof-of-concept systems into commercial medical devices are provided.
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Affiliation(s)
- Ashna Gopal
- School of Engineering Institute for Bioengineering The University of Edinburgh Edinburgh EH9 3JL UK
| | - Li Yan
- College of Health Science and Environmental Engineering Shenzhen Technology University Shenzhen 518118 China
| | - Saima Kashif
- School of Engineering Institute for Bioengineering The University of Edinburgh Edinburgh EH9 3JL UK
| | - Tasnim Munshi
- School of Chemistry University of Lincoln, Brayford Pool Lincoln Lincolnshire LN6 7TS UK
| | | | - Nicolas H. Voelcker
- Drug Delivery Disposition and Dynamics Monash Institute of Pharmaceutical Sciences Monash University Parkville Victoria VIC 3052 Australia
- Melbourne Centre for Nanofabrication Victorian Node of the Australian National Fabrication Facility Clayton Victoria 3168 Australia
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Clayton Victoria 3168 Australia
| | - Xianfeng Chen
- School of Engineering Institute for Bioengineering The University of Edinburgh Edinburgh EH9 3JL UK
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2
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Stewart KME, Al‐Ghamdi M, Khater M, Abdel‐Rahman EM, Penlidis A. An overview of sensors and sensing materials for heavy metals in aqueous environments. CAN J CHEM ENG 2021. [DOI: 10.1002/cjce.24139] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
| | - Majed Al‐Ghamdi
- National Center for Electronics and Photonics Technology, King Abdulaziz City for Science and Technology (KACST) Riyadh Saudi Arabia
| | - Mahmoud Khater
- Department of Mechanical Engineering KFUPM Dhahran Saudi Arabia
| | - Eihab M. Abdel‐Rahman
- Department of Systems Design Engineering University of Waterloo Waterloo Ontario Canada
| | - Alexander Penlidis
- Department of Chemical Engineering, Institute for Polymer Research University of Waterloo Waterloo Ontario Canada
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3
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Kabir H, Merati M, Abdekhodaie MJ. Design of an effective piezoelectric microcantilever biosensor for rapid detection of COVID-19. J Med Eng Technol 2021; 45:423-433. [PMID: 33998955 DOI: 10.1080/03091902.2021.1921067] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also called COVID-19, is one of the most contagious viruses resulting in a progressive pandemic. Since specific antiviral treatments have not been developed yet and its fatal rate is almost high, early and fast detection is critical for controlling the outbreak. In this study, a piezoelectric microcantilever biosensor has been designed for detecting COVID-19 samples directly without requiring preparation steps. The biosensor acts as a transducer and is coated with the related antibody. When the SARS-CoV-2 antigens adsorbed on the microcantilever top surface through their spike proteins, a surface stress due to the mass change would be prompted leading to the measurable tip deflection and floating voltage. To obtain a biosensor with optimum parameters, different shapes and piezoelectric materials have been assessed and it was concluded that a Poly (vinylidene fluoride) (PVDF) biosensor in a shape of a holed punched form triangle, represented the best result. Therefore, the highly sensitive microcantilever biosensor can detect COVID-19 in clinical samples with various viral loads, rapidly. Also, it is selective enough to differentiate SARS-CoV-2 from other viruses with similar symptoms.
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Affiliation(s)
- Hannaneh Kabir
- Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
| | - Mohsen Merati
- School of Medicine, Tehran University of Medical Science, Tehran, Iran
| | - Mohammad J Abdekhodaie
- Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran.,Yeates School of Graduate Studies, Ryerson University, Toronto, ON, Canada
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4
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Alunda BO, Lee YJ. Review: Cantilever-Based Sensors for High Speed Atomic Force Microscopy. SENSORS (BASEL, SWITZERLAND) 2020; 20:E4784. [PMID: 32854193 PMCID: PMC7506678 DOI: 10.3390/s20174784] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022]
Abstract
This review critically summarizes the recent advances of the microcantilever-based force sensors for atomic force microscope (AFM) applications. They are one the most common mechanical spring-mass systems and are extremely sensitive to changes in the resonant frequency, thus finding numerous applications especially for molecular sensing. Specifically, we comment on the latest progress in research on the deflection detection systems, fabrication, coating and functionalization of the microcantilevers and their application as bio- and chemical sensors. A trend on the recent breakthroughs on the study of biological samples using high-speed atomic force microscope is also reported in this review.
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Affiliation(s)
- Bernard Ouma Alunda
- School of Mines and Engineering, Taita Taveta University, P.O. Box 635-80300 Voi, Kenya;
| | - Yong Joong Lee
- School of Mechanical Engineering, Kyungpook National University, Daegu 41566, Korea
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5
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Agarwal DK, Kushagra A, Ashwin M, Shukla AS, Palaparthy V. Sensitive detection of cardiac troponin-I protein using fabricated piezoresistive microcantilevers by a novel method of asymmetric biofunctionalization. NANOTECHNOLOGY 2020; 31:115503. [PMID: 31751958 DOI: 10.1088/1361-6528/ab5a18] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Microcantilever-based sensor platform has attracted a lot of attention over the time in detection of a variety of molecules due to their miniaturized dimensions. Sensitivity enhancement is an important aspect of such sensors, especially when used for point-of-care diagnostic purpose. However, the major concern while operating these sensors in deflection mode is their sensitivity which mainly relies on selective chemical modification protocols employed on these sensor surfaces. One of the ways of getting better sensitivity is through asymmetric (one side) biofunctionalization of the sensor surface. In the presented work here, we have demonstrated a novel approach of asymmetric biofunctionalization of proteins in overall sensitivity enhancement of piezoresistive silicon nitride-oxide microcantilever sensor platform inside a flow chamber. Herein, using our developed surface chemistry, asymmetrically biofunctionalized microcantilevers first exhibited a greater electrical response in terms of piezoresistance change than their symmetric counterpart in the detection of human immunoglobulins (HIgGs) protein. Finally, these microcantilevers were employed to exhibit the enhanced sensitivity towards the detection of a crucial cardiac marker protein, i.e. Troponin-I (cTnI) down to 250 ng ml-1 using asymmetric biofunctionalization process. This study shows that the developed asymmetric biofunctionalization methodology may be used as a general protocol to detect other important biomarkers of clinical applications with improved sensitivity.
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Affiliation(s)
- Dilip Kumar Agarwal
- Centre for Research in Nanotechnology and Science, Indian Institute of Technology Bombay, Mumbai, India. Centre of Excellence in Nanoelectronics, Dept. of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai, India
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6
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Detection of heart-type fatty acid-binding protein (h-FABP) using piezoresistive polymer microcantilevers functionalized by a dry method. APPLIED NANOSCIENCE 2018. [DOI: 10.1007/s13204-018-0723-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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7
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A Real-Time Thermal Self-Elimination Method for Static Mode Operated Freestanding Piezoresistive Microcantilever-Based Biosensors. BIOSENSORS-BASEL 2018; 8:bios8010018. [PMID: 29495574 PMCID: PMC5872066 DOI: 10.3390/bios8010018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/19/2018] [Accepted: 02/26/2018] [Indexed: 11/16/2022]
Abstract
Here, we provide a method and apparatus for real-time compensation of the thermal effect of single free-standing piezoresistive microcantilever-based biosensors. The sensor chip contained an on-chip fixed piezoresistor that served as a temperature sensor, and a multilayer microcantilever with an embedded piezoresistor served as a biomolecular sensor. This method employed the calibrated relationship between the resistance and the temperature of piezoresistors to eliminate the thermal effect on the sensor, including the temperature coefficient of resistance (TCR) and bimorph effect. From experimental results, the method was verified to reduce the signal of thermal effect from 25.6 μV/°C to 0.3 μV/°C, which was approximately two orders of magnitude less than that before the processing of the thermal elimination method. Furthermore, the proposed approach and system successfully demonstrated its effective real-time thermal self-elimination on biomolecular detection without any thermostat device to control the environmental temperature. This method realizes the miniaturization of an overall measurement system of the sensor, which can be used to develop portable medical devices and microarray analysis platforms.
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8
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Mathew R, Ravi Sankar A. A Review on Surface Stress-Based Miniaturized Piezoresistive SU-8 Polymeric Cantilever Sensors. NANO-MICRO LETTERS 2018; 10:35. [PMID: 30393684 PMCID: PMC6199092 DOI: 10.1007/s40820-018-0189-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/02/2018] [Indexed: 05/30/2023]
Abstract
In the last decade, microelectromechanical systems (MEMS) SU-8 polymeric cantilevers with piezoresistive readout combined with the advances in molecular recognition techniques have found versatile applications, especially in the field of chemical and biological sensing. Compared to conventional solid-state semiconductor-based piezoresistive cantilever sensors, SU-8 polymeric cantilevers have advantages in terms of better sensitivity along with reduced material and fabrication cost. In recent times, numerous researchers have investigated their potential as a sensing platform due to high performance-to-cost ratio of SU-8 polymer-based cantilever sensors. In this article, we critically review the design, fabrication, and performance aspects of surface stress-based piezoresistive SU-8 polymeric cantilever sensors. The evolution of surface stress-based piezoresistive cantilever sensors from solid-state semiconductor materials to polymers, especially SU-8 polymer, is discussed in detail. Theoretical principles of surface stress generation and their application in cantilever sensing technology are also devised. Variants of SU-8 polymeric cantilevers with different composition of materials in cantilever stacks are explained. Furthermore, the interdependence of the material selection, geometrical design parameters, and fabrication process of piezoresistive SU-8 polymeric cantilever sensors and their cumulative impact on the sensor response are also explained in detail. In addition to the design-, fabrication-, and performance-related factors, this article also describes various challenges in engineering SU-8 polymeric cantilevers as a universal sensing platform such as temperature and moisture vulnerability. This review article would serve as a guideline for researchers to understand specifics and functionality of surface stress-based piezoresistive SU-8 cantilever sensors.
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Affiliation(s)
- Ribu Mathew
- School of Electronics Engineering (SENSE), Vellore Institute of Technology (VIT) Chennai, Chennai, Tamil Nadu 600127 India
| | - A. Ravi Sankar
- School of Electronics Engineering (SENSE), Vellore Institute of Technology (VIT) Chennai, Chennai, Tamil Nadu 600127 India
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9
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Choi YS, Gwak MJ, Lee DW. Polymeric cantilever integrated with PDMS/graphene composite strain sensor. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:105004. [PMID: 27802725 DOI: 10.1063/1.4962925] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This paper describes the mechanical and electrical characteristics of a polydimethylsiloxane (PDMS) cantilever integrated with a high-sensitivity strain sensor. The strain sensor is fabricated using PDMS and graphene flakes that are uniformly distributed in the PDMS. In order to prepare PDMS/graphene composite with uniform resistance, a tetrahydrofuran solution is used to decrease the viscosity of a PDMS base polymer solution. A horn-type sonicator is then used to mix the base polymer with graphene flakes. Low viscosity of the base polymer solution improves the reliability and reproducibility of the PDMS/graphene composite for strain sensor applications. After dicing the composite into the desired sensor shape, a tensile test is performed. The experimental results show that the composite with a concentration of 30 wt.% exhibits a linear response up to a strain rate of 9%. The graphene concentration of the prepared materials affects the gauge factor, which at 20% graphene concentration reaches about 50, and with increasing graphene concentration to 30% decreases to 9. Furthermore, photolithography, PDMS casting, and a stencil process are used to fabricate a PDMS cantilever with an integrated strain sensor. The change in resistance of the integrated PDMS/graphene sensor is characterized with respect to the displacement of the cantilever of within 500 μm. The experimental results confirmed that the prepared PDMS/graphene based sensor has the potential for high-sensitive biosensor applications.
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Affiliation(s)
- Young-Soo Choi
- MEMS and Nanotechnology Lab, School of Mechanical Engineering Chonnam National University, Gwangju 500757, South Korea
| | - Min-Joo Gwak
- MEMS and Nanotechnology Lab, School of Mechanical Engineering Chonnam National University, Gwangju 500757, South Korea
| | - Dong-Weon Lee
- MEMS and Nanotechnology Lab, School of Mechanical Engineering Chonnam National University, Gwangju 500757, South Korea
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10
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Mathew R, Sankar AR. Numerical study on the influence of buried oxide layer of SOI wafers on the terminal characteristics of a micro/nano cantilever biosensor with an integrated piezoresistor. Biomed Phys Eng Express 2016. [DOI: 10.1088/2057-1976/2/5/055012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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11
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Lifson MA, Ozen MO, Inci F, Wang S, Inan H, Baday M, Henrich TJ, Demirci U. Advances in biosensing strategies for HIV-1 detection, diagnosis, and therapeutic monitoring. Adv Drug Deliv Rev 2016; 103:90-104. [PMID: 27262924 PMCID: PMC4943868 DOI: 10.1016/j.addr.2016.05.018] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 05/24/2016] [Accepted: 05/25/2016] [Indexed: 01/01/2023]
Abstract
HIV-1 is a major global epidemic that requires sophisticated clinical management. There have been remarkable efforts to develop new strategies for detecting and treating HIV-1, as it has been challenging to translate them into resource-limited settings. Significant research efforts have been recently devoted to developing point-of-care (POC) diagnostics that can monitor HIV-1 viral load with high sensitivity by leveraging micro- and nano-scale technologies. These POC devices can be applied to monitoring of antiretroviral therapy, during mother-to-child transmission, and identification of latent HIV-1 reservoirs. In this review, we discuss current challenges in HIV-1 diagnosis and therapy in resource-limited settings and present emerging technologies that aim to address these challenges using innovative solutions.
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Affiliation(s)
- Mark A Lifson
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Radiology Department, Canary Center at Stanford for Cancer Early Detection, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Mehmet Ozgun Ozen
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Radiology Department, Canary Center at Stanford for Cancer Early Detection, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Fatih Inci
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Radiology Department, Canary Center at Stanford for Cancer Early Detection, Stanford University School of Medicine, Palo Alto, CA, USA
| | - ShuQi Wang
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Radiology Department, Canary Center at Stanford for Cancer Early Detection, Stanford University School of Medicine, Palo Alto, CA, USA; State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China; Institute for Translational Medicine, Zhejiang University, Hangzhou, China
| | - Hakan Inan
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Radiology Department, Canary Center at Stanford for Cancer Early Detection, Stanford University School of Medicine, Palo Alto, CA, USA; Medicine Faculty, Zirve University, Gaziantep, Turkey
| | - Murat Baday
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Radiology Department, Canary Center at Stanford for Cancer Early Detection, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Timothy J Henrich
- Division of Experimental Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Utkan Demirci
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Radiology Department, Canary Center at Stanford for Cancer Early Detection, Stanford University School of Medicine, Palo Alto, CA, USA
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12
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Agarwal DK, Maheshwari N, Mukherji S, Rao VR. Asymmetric immobilization of antibodies on a piezo-resistive micro-cantilever surface. RSC Adv 2016. [DOI: 10.1039/c6ra01440b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
For cantilever-based MEMS sensors, selective chemical modification of the sensing surface is used for the detection of chemical and biological analytes.
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Affiliation(s)
- Dilip Kumar Agarwal
- Centre of Excellence in Nanoelectronics
- Dept. of Electrical Engineering
- IIT Bombay
- Mumbai
- India
| | - Nidhi Maheshwari
- Centre of Excellence in Nanoelectronics
- Dept. of Electrical Engineering
- IIT Bombay
- Mumbai
- India
| | - Soumyo Mukherji
- Centre of Excellence in Nanoelectronics
- Dept. of Electrical Engineering
- IIT Bombay
- Mumbai
- India
| | - V. Ramgopal Rao
- Centre of Excellence in Nanoelectronics
- Dept. of Electrical Engineering
- IIT Bombay
- Mumbai
- India
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13
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Dultsev F, Kolosovsky E, Cooper M, Lomzov A, Pyshnyi D. QCM-based rapid analysis of DNA. SENSING AND BIO-SENSING RESEARCH 2015. [DOI: 10.1016/j.sbsr.2014.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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14
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Ferrier DC, Shaver MP, Hands PJW. Micro- and nano-structure based oligonucleotide sensors. Biosens Bioelectron 2015; 68:798-810. [PMID: 25655465 DOI: 10.1016/j.bios.2015.01.031] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/12/2015] [Accepted: 01/13/2015] [Indexed: 12/26/2022]
Abstract
This paper presents a review of micro- and nano-structure based oligonucleotide detection and quantification techniques. The characteristics of such devices make them very attractive for Point-of-Care or On-Site-Testing biosensing applications. Their small scale means that they can be robust and portable, their compatibility with modern CMOS electronics means that they can easily be incorporated into hand-held devices and their suitability for mass production means that, out of the different approaches to oligonucleotide detection, they are the most suitable for commercialisation. This review discusses the advantages of micro- and nano-structure based sensors and covers the various oligonucleotide detection techniques that have been developed to date. These include: Bulk Acoustic Wave and Surface Acoustic Wave devices, micro- and nano-cantilever sensors, gene Field Effect Transistors, and nanowire and nanopore based sensors. Oligonucleotide immobilisation techniques are also discussed.
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Affiliation(s)
- David C Ferrier
- School of Engineering, University of Edinburgh, Edinburgh EH9 3JL, UK
| | - Michael P Shaver
- School of Chemistry, David Brewster Road, University of Edinburgh, Edinburgh EH9 3FJ, UK
| | - Philip J W Hands
- School of Engineering, University of Edinburgh, Edinburgh EH9 3JL, UK.
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15
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Ghosh S, Mishra S, Mukhopadhyay R. Enhancing sensitivity in a piezoresistive cantilever-based label-free DNA detection assay using ssPNA sensor probes. J Mater Chem B 2014; 2:960-970. [DOI: 10.1039/c3tb21392g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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High S/N ratio slotted step piezoresistive microcantilever designs for biosensors. SENSORS 2013; 13:4088-101. [PMID: 23535637 PMCID: PMC3673072 DOI: 10.3390/s130404088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/01/2013] [Accepted: 03/22/2013] [Indexed: 11/25/2022]
Abstract
This study proposes new microcantilever designs in slotted step configuration to improve the S/N ratio of surface stress-based sensors used in physical, chemical, biochemical and biosensor applications. The cantilevers are made of silicon dioxide with a u-shaped silicon piezoresistor in p-doped. The cantilever step length and piezoresistor length is varied along with the operating voltage to characterise the surface stress sensitivity and thermal drifting sensitivity of the cantilevers when used as immunosensor. The numerical analysis is performed using ANSYS Multiphysics. Results show the surface stress sensitivity and the S/N ratio of the slotted step cantilevers is improved by more than 32% and 22%, respectively, over its monolithic counterparts.
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17
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Atomic force microscopy as a tool applied to nano/biosensors. SENSORS 2012; 12:8278-300. [PMID: 22969400 PMCID: PMC3436029 DOI: 10.3390/s120608278] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/01/2012] [Accepted: 06/05/2012] [Indexed: 11/17/2022]
Abstract
This review article discusses and documents the basic concepts and principles of nano/biosensors. More specifically, we comment on the use of Chemical Force Microscopy (CFM) to study various aspects of architectural and chemical design details of specific molecules and polymers and its influence on the control of chemical interactions between the Atomic Force Microscopy (AFM) tip and the sample. This technique is based on the fabrication of nanomechanical cantilever sensors (NCS) and microcantilever-based biosensors (MC-B), which can provide, depending on the application, rapid, sensitive, simple and low-cost in situ detection. Besides, it can provide high repeatability and reproducibility. Here, we review the applications of CFM through some application examples which should function as methodological questions to understand and transform this tool into a reliable source of data. This section is followed by a description of the theoretical principle and usage of the functionalized NCS and MC-B technique in several fields, such as agriculture, biotechnology and immunoassay. Finally, we hope this review will help the reader to appreciate how important the tools CFM, NCS and MC-B are for characterization and understanding of systems on the atomic scale.
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18
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Comparison between conduction and convection effects on self-heating in doped microcantilevers. SENSORS 2012; 12:1758-70. [PMID: 22438736 PMCID: PMC3304138 DOI: 10.3390/s120201758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 02/01/2012] [Accepted: 02/03/2012] [Indexed: 12/03/2022]
Abstract
The present study investigates the effects of thermal conduction and convection on self-heating temperatures and bimetallic deflections produced in doped microcantilever sensors. These cantilevers are commonly used as sensors and actuators in microsystems. The cantilever is a monolith, multi-layer structure with a thin U-shaped element inside. The cantilever substrate is made of silicon and silicon dioxide, respectively, and the element is p-doped silicon. A numerical analysis package (ANSYS) is used to study the effect of cantilever substrate material, element width, applied voltage and the operating environments on cantilever characteristics. The numerical results for temperature are compared against their analytical models. Results indicate the numerical results are accurate within 6% of analytical, and Si/Si cantilevers are more suitable for biosensors and AFM, whereas, Si/SiO2 are for hotplates and actuators applications.
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Cheneler D, Bowen J, Leigh S, Purssell C, Billson D, Hutchins D, Ward M. Fabrication and analysis of cylindrical resin AFM microcantilevers. Ultramicroscopy 2011; 111:1214-23. [DOI: 10.1016/j.ultramic.2011.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2010] [Revised: 02/25/2011] [Accepted: 03/11/2011] [Indexed: 10/18/2022]
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20
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Anderson RR, Hu W, Noh JW, Dahlquist WC, Ness SJ, Gustafson TM, Richards DC, Kim S, Mazzeo BA, Woolley AT, Nordin GP. Transient deflection response in microcantilever array integrated with polydimethylsiloxane (PDMS) microfluidics. LAB ON A CHIP 2011; 11:2088-96. [PMID: 21547316 DOI: 10.1039/c1lc20025a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We report the integration of a nanomechanical sensor consisting of 16 silicon microcantilevers with polydimethylsiloxane (PDMS) microfluidics. For microcantilevers positioned near the bottom of a microfluidic flow channel, a transient differential analyte concentration for the top versus bottom surface of each microcantilever is created when an analyte-bearing fluid is introduced into the flow channel (which is initially filled with a non-analyte containing solution). We use this effect to characterize a bare (nonfunctionalized) microcantilever array in which the microcantilevers are simultaneously read out with our recently developed high sensitivity in-plane photonic transduction method. We first examine the case of non-specific binding of bovine serum albumin (BSA) to silicon. The average maximum transient microcantilever deflection in the array is -1.6 nm, which corresponds to a differential surface stress of only -0.23 mN m(-1). This is in excellent agreement with the maximum differential surface stress calculated based on a modified rate equation in conjunction with finite element simulation. Following BSA adsorption, buffer solutions with different pH are introduced to further study microcantilever array transient response. Deflections of 20-100 nm are observed (2-14 mN m(-1) differential surface stress). At a flow rate of 5 μL min(-1), the average measured temporal width (FWHM) of the transient response is 5.3 s for BSA non-specific binding and 0.74 s for pH changes.
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Affiliation(s)
- Ryan R Anderson
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA
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Bache M, Taboryski R, Schmid S, Aamand J, Jakobsen MH. Investigations on antibody binding to a micro-cantilever coated with a BAM pesticide residue. NANOSCALE RESEARCH LETTERS 2011; 6:386. [PMID: 21711907 PMCID: PMC3211479 DOI: 10.1186/1556-276x-6-386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 05/16/2011] [Indexed: 05/31/2023]
Abstract
The attachment of an antibody to an antigen-coated cantilever has been investigated by repeated experiments, using a cantilever-based detection system by Cantion A/S. The stress induced by the binding of a pesticide residue BAM (2,6 dichlorobenzamide) immobilized on a cantilever surface to anti-BAM antibody is measured using the CantiLab4© system from Cantion A/S with four gold-coated cantilevers and piezo resistive readout. The detection mechanism is in principle label-free, but fluorescent-marked antibodies have been used to subsequently verify the binding on the cantilever surface. The bending and increase in mass of each cantilever has also been investigated using a light interferometer and a Doppler Vibrometer. The system has been analyzed during repeated measurements to investigate whether the CantiLab4© system is a suited platform for a pesticide assay system.
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Affiliation(s)
- Michael Bache
- Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, 2800 Kongens Lyngby, Denmark
| | - Rafael Taboryski
- Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, 2800 Kongens Lyngby, Denmark
| | - Silvan Schmid
- Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, 2800 Kongens Lyngby, Denmark
| | - Jens Aamand
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster voldgade 10, DK-1350 Copenhagen K, Denmark
| | - Mogens Havsteen Jakobsen
- Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, 2800 Kongens Lyngby, Denmark
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Arlett J, Myers E, Roukes M. Comparative advantages of mechanical biosensors. NATURE NANOTECHNOLOGY 2011; 6:203-15. [PMID: 21441911 PMCID: PMC3839312 DOI: 10.1038/nnano.2011.44] [Citation(s) in RCA: 438] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Mechanical interactions are fundamental to biology. Mechanical forces of chemical origin determine motility and adhesion on the cellular scale, and govern transport and affinity on the molecular scale. Biological sensing in the mechanical domain provides unique opportunities to measure forces, displacements and mass changes from cellular and subcellular processes. Nanomechanical systems are particularly well matched in size with molecular interactions, and provide a basis for biological probes with single-molecule sensitivity. Here we review micro- and nanoscale biosensors, with a particular focus on fast mechanical biosensing in fluid by mass- and force-based methods, and the challenges presented by non-specific interactions. We explain the general issues that will be critical to the success of any type of next-generation mechanical biosensor, such as the need to improve intrinsic device performance, fabrication reproducibility and system integration. We also discuss the need for a greater understanding of analyte-sensor interactions on the nanoscale and of stochastic processes in the sensing environment.
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Affiliation(s)
| | | | - M.L. Roukes
- Kavli Nanoscience Institute and Departments of Physics, Applied Physics, and Bioengineering, California Institute of Technology, MC 149-33 Pasadena, California 91125, USA.
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An analytical model of joule heating in piezoresistive microcantilevers. SENSORS 2010; 10:9668-86. [PMID: 22163433 PMCID: PMC3231039 DOI: 10.3390/s101109668] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Revised: 09/27/2010] [Accepted: 10/09/2010] [Indexed: 11/16/2022]
Abstract
The present study investigates Joule heating in piezoresistive microcantilever sensors. Joule heating and thermal deflections are a major source of noise in such sensors. This work uses analytical and numerical techniques to characterise the Joule heating in 4-layer piezoresistive microcantilevers made of silicon and silicon dioxide substrates but with the same U-shaped silicon piezoresistor. A theoretical model for predicting the temperature generated due to Joule heating is developed. The commercial finite element software ANSYS Multiphysics was used to study the effect of electrical potential on temperature and deflection produced in the cantilevers. The effect of piezoresistor width on Joule heating is also studied. Results show that Joule heating strongly depends on the applied potential and width of piezoresistor and that a silicon substrate cantilever has better thermal characteristics than a silicon dioxide cantilever.
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Tark SH, Das A, Sligar S, Dravid VP. Nanomechanical detection of cholera toxin using microcantilevers functionalized with ganglioside nanodiscs. NANOTECHNOLOGY 2010; 21:435502. [PMID: 20890017 PMCID: PMC3868204 DOI: 10.1088/0957-4484/21/43/435502] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The label-free detection of cholera toxin is demonstrated using microcantilevers functionalized with ganglioside nanodiscs. The cholera toxin molecules bind specifically to the active membrane protein encased in nanodiscs, nanoscale lipid bilayers surrounded by an amphipathic protein belt, immobilized on the cantilever surface. The specific molecular binding results in cantilever deflection via the formation of a surface stress-induced bending moment. The nanomechanical cantilever response is quantitatively monitored by optical interference. The consistent and reproducible nanomechanical detection of cholera toxin in nanomolar range concentrations is demonstrated. The results validated with such a model system suggest that the combination of a microcantilever platform with receptor nanodiscs is a promising approach for monitoring invasive pathogens and other types of biomolecular detection relevant to drug discovery.
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Affiliation(s)
- Soo-Hyun Tark
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Aditi Das
- Department of Biochemistry and Chemistry, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Stephen Sligar
- Department of Biochemistry and Chemistry, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Vinayak P. Dravid
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA
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25
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Kim S, Rahman T, Senesac LR, Davison BH, Thundat T. Piezoresistive cantilever array sensor for consolidated bioprocess monitoring. SCANNING 2009; 31:204-210. [PMID: 20027646 DOI: 10.1002/sca.20159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Cellulolytic microbes occur in diverse natural niches and are being screened for industrial modification and utility. A microbe for consolidated bioprocessing (CBP) development can rapidly degrade pure cellulose and then ferment the resulting sugars into fuels. To identify and screen for novel microbes for CBP, we have developed a piezoresistive cantilever array sensor which is capable of simultaneous monitoring of glucose and ethanol concentration changes in a phosphate buffer solution. 4-mercaptophenylboronic acid and polyethyleneglycol-thiol are employed to functionalize each piezoresistive cantilever for glucose and ethanol sensing, respectively. Successful concentration measurements of glucose and ethanol with minimal interferences are obtained with our cantilever array sensor.
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Affiliation(s)
- Seonghwan Kim
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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26
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Hu W, Anderson R, Qian Y, Song J, Noh JW, Kim S, Nordin GP. Demonstration of microcantilever array with simultaneous readout using an in-plane photonic transduction method. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:085101. [PMID: 19725675 DOI: 10.1063/1.3186735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We demonstrate a microcantilever array with an in-plane photonic transduction method for simultaneous readout of each microcantilever. The array is fabricated on a silicon-on-insulator substrate. Rib waveguides in conjunction with a compact waveguide splitter network comprised of trench-based splitters and trench-based bends route light from a single optical input to each microcantilever on the chip. Light propagates down a rib waveguide integrated into the microcantilever and, at the free end of the microcantilever, crosses a small gap. Light is captured in static asymmetric multimode waveguides that terminate in Y-branches, the outputs of which are imaged onto an InGaAs line scan camera. A differential signal for each microcantilever is simultaneously formed from the two outputs of the corresponding Y-branch. We demonstrate that reasonable signal uniformity is obtained with a scaled differential signal for seven out of nine surviving microcantilevers in an array.
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Affiliation(s)
- Weisheng Hu
- Electrical and Computer Engineering, Brigham Young University, Provo, Utah 84602, USA
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27
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Barlian AA, Park WT, Mallon JR, Rastegar AJ, Pruitt BL. Review: Semiconductor Piezoresistance for Microsystems. PROCEEDINGS OF THE IEEE. INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS 2009; 97:513-552. [PMID: 20198118 PMCID: PMC2829857 DOI: 10.1109/jproc.2009.2013612] [Citation(s) in RCA: 188] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Piezoresistive sensors are among the earliest micromachined silicon devices. The need for smaller, less expensive, higher performance sensors helped drive early micromachining technology, a precursor to microsystems or microelectromechanical systems (MEMS). The effect of stress on doped silicon and germanium has been known since the work of Smith at Bell Laboratories in 1954. Since then, researchers have extensively reported on microscale, piezoresistive strain gauges, pressure sensors, accelerometers, and cantilever force/displacement sensors, including many commercially successful devices. In this paper, we review the history of piezoresistance, its physics and related fabrication techniques. We also discuss electrical noise in piezoresistors, device examples and design considerations, and alternative materials. This paper provides a comprehensive overview of integrated piezoresistor technology with an introduction to the physics of piezoresistivity, process and material selection and design guidance useful to researchers and device engineers.
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28
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Noh JW, Anderson R, Kim S, Cardenas J, Nordin GP. In-plane photonic transduction of silicon-on-insulator microcantilevers. OPTICS EXPRESS 2008; 16:12114-12123. [PMID: 18679487 DOI: 10.1364/oe.16.012114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We demonstrate an in-plane photonic transduction method for microcantilevers, which have been widely investigated for sensor applications. In our approach the microcantilever is etched to form a single mode rib waveguide. Light propagates down the microcantilever and crosses a small gap at the free end of the microcantilever, some of which is captured by an asymmetrical multimode waveguide that terminates in a Y-branch. The Y-branch outputs are used to form a differential signal that is monotonically dependent on microcantilever deflection. The measured differential signal matches simulation when microcantilever rotation is properly accounted for. The measured differential signal sensitivity is 1.4 x 10(-4) nm(-1) and the minimum detectable deflection is 0.35 nm.
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Affiliation(s)
- Jong Wook Noh
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA
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29
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Abstract
This review will provide a general introduction to the field of cantilever biosensors by discussing the basic principles and the basic technical background necessary to understand and evaluate this class of sensors. Microfabricated cantilever sensors respond to changes in their environment or changes on their surface with a mechanical bending in the order of nanometers which can easily be detected. They are able to detect pH and temperature changes, the formation of self-assembled monolayers, DNA hybridization, antibody-antigen interactions, or the adsorption of bacteria. The review will focus on the surface stress mode of microfabricated cantilever arrays and their application as biosensors in molecular life science. A general background on biosensors, an overview of the different modes of operation of cantilever sensors and some details on sensor functionalization will be given. Finally, key experiments and current theoretical efforts to describe the surface stress mode of cantilever sensors will be discussed.
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Affiliation(s)
- Jürgen Fritz
- Jacobs University Bremen, School of Engineering and Science, Campus Ring 1, 28759 Bremen, Germany.
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30
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Nordström M, Keller S, Lillemose M, Johansson A, Dohn S, Haefliger D, Blagoi G, Havsteen-Jakobsen M, Boisen A. SU-8 Cantilevers for Bio/chemical Sensing; Fabrication, Characterisation and Development of Novel Read-out Methods. SENSORS 2008; 8:1595-1612. [PMID: 27879783 PMCID: PMC3663014 DOI: 10.3390/s8031595] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Accepted: 03/03/2008] [Indexed: 11/16/2022]
Abstract
Here, we present the activities within our research group over the last five yearswith cantilevers fabricated in the polymer SU-8. We believe that SU-8 is an interestingpolymer for fabrication of cantilevers for bio/chemical sensing due to its simple processingand low Young's modulus. We show examples of different integrated read-out methodsand their characterisation. We also show that SU-8 cantilevers have a reduced sensitivity tochanges in the environmental temperature and pH of the buffer solution. Moreover, weshow that the SU-8 cantilever surface can be functionalised directly with receptormolecules for analyte detection, thereby avoiding gold-thiol chemistry.
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Affiliation(s)
- Maria Nordström
- MIC - Department of Micro and Nanotechnology, Technical University of Denmark, DTU building 345 East, DK-2800 Kongens Lyngby, Denmark.
| | - Stephan Keller
- MIC - Department of Micro and Nanotechnology, Technical University of Denmark, DTU building 345 East, DK-2800 Kongens Lyngby, Denmark
| | - Michael Lillemose
- MIC - Department of Micro and Nanotechnology, Technical University of Denmark, DTU building 345 East, DK-2800 Kongens Lyngby, Denmark
| | | | - Søren Dohn
- MIC - Department of Micro and Nanotechnology, Technical University of Denmark, DTU building 345 East, DK-2800 Kongens Lyngby, Denmark
| | | | - Gabriela Blagoi
- MIC - Department of Micro and Nanotechnology, Technical University of Denmark, DTU building 345 East, DK-2800 Kongens Lyngby, Denmark
| | - Mogens Havsteen-Jakobsen
- MIC - Department of Micro and Nanotechnology, Technical University of Denmark, DTU building 345 East, DK-2800 Kongens Lyngby, Denmark
| | - Anja Boisen
- MIC - Department of Micro and Nanotechnology, Technical University of Denmark, DTU building 345 East, DK-2800 Kongens Lyngby, Denmark
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31
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Loui A, Ratto TV, Wilson TS, McCall SK, Mukerjee EV, Love AH, Hart BR. Chemical vapor discrimination using a compact and low-power array of piezoresistive microcantilevers. Analyst 2008; 133:608-15. [DOI: 10.1039/b713758c] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Wehrmeister J, Fuss A, Saurenbach F, Berger R, Helm M. Readout of micromechanical cantilever sensor arrays by Fabry-Perot interferometry. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2007; 78:104105. [PMID: 17979440 DOI: 10.1063/1.2785028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The increasing use of micromechanical cantilevers in sensing applications causes a need for reliable readout techniques of micromechanical cantilever sensor (MCS) bending. Current optical beam deflection techniques suffer from drawbacks such as artifacts due to changes in the refraction index upon exchange of media. Here, an adaptation of the Fabry-Perot interferometer is presented that allows simultaneous determination of MCS bending and changes in the refraction index of media. Calibration of the instrument with liquids of known refraction index provides an avenue to direct measurement of bending with nanometer precision. Versatile construction of flow cells in combination with alignment features for substrate chips allows simultaneous measurement of two MCS situated either on the same, or on two different support chips. The performance of the instrument is demonstrate in several sensing applications, including adsorption experiments of alkanethioles on MCS gold surfaces, and measurement of humidity changes in air.
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Affiliation(s)
- Jana Wehrmeister
- Institut für Pharmazie und Molekulare Biotechnologie, Department of Chemistry, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany
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33
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Legay G, Markey L, Meunier-Prest R, Finot E. Measurements of thickness dispersion in biolayers by scanning force microscopy and comparison with spectroscopic ellipsometry analysis. Ultramicroscopy 2007; 107:1111-7. [PMID: 17582684 DOI: 10.1016/j.ultramic.2007.02.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2006] [Accepted: 02/12/2007] [Indexed: 10/23/2022]
Abstract
Measuring the thickness of biological films remains a difficult task when using differential measurements by atomic force microscopy (AFM). The use of microstructured substrates combined with a selective adsorption constitutes an alternative to tribological measurements. The statistical thickness analysis of biological layers, especially via the dispersion measurements, can provide a way to quantify the molecular orientation. AFM thicknesses were then compared with those obtained optically by spectroscopic ellipsometry (SE) and surface plasmon resonance enhanced ellipsometry (SPREE). The biolayers could then be modeled using a vertical gradient of optical index, which reflects height dispersions. Thiol-modified DNA strands of various lengths account for a good biological model for the study of the strand motion in air and in liquid.
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Affiliation(s)
- Guillaume Legay
- Laboratoire de Physique Université de Bourgogne, UMR CNRS 5027, F-21011 Dijon, France
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34
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Shekhawat G, Tark SH, Dravid VP. MOSFET-Embedded Microcantilevers for Measuring Deflection in Biomolecular Sensors. Science 2006; 311:1592-5. [PMID: 16456038 DOI: 10.1126/science.1122588] [Citation(s) in RCA: 229] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A promising approach for detecting biomolecules follows their binding to immobilized probe molecules on microfabricated cantilevers; binding causes surface stresses that bend the cantilever. We measured this deflection, which is on the order of tens of nanometers, by embedding a metal-oxide semiconductor field-effect transistor (MOSFET) into the base of the cantilever and recording decreases in drain current with deflections as small as 5 nanometers. The gate region of the MOSFET responds to surface stresses and thus is embedded in silicon nitride so as to avoid direct contact with the sample solution. This approach, which offers low noise, high sensitivity, and direct readout, was used to detect specific binding events with biotin and antibodies.
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Affiliation(s)
- Gajendra Shekhawat
- International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208, USA.
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35
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Legay G, Finot E, Meunier-Prest R, Cherkaoui-Malki M, Latruffe N, Dereux A. DNA nanofilm thickness measurement on microarray in air and in liquid using an atomic force microscope. Biosens Bioelectron 2006; 21:627-36. [PMID: 16202876 DOI: 10.1016/j.bios.2004.12.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Revised: 12/01/2004] [Accepted: 12/23/2004] [Indexed: 11/29/2022]
Abstract
The measurement of the thickness of DNA films on microarray as a function of the medium (liquid, air) is gaining importance for understanding the signal response of biosensors. Thiol group has been used to attach DNA strands to gold micropads deposited on silicon surface. Atomic force microscopy (AFM) was employed in its height mode to measure the change in the pad thickness and in its force mode to measure the indentation depth of the nanofilm. A good coherence between the height and force modes is observed for the film thickness in air. The adhesion force was found to be an alternative way to measure the surface coverage of the biolayer at nanoscopic scale. However the force analysis (compression, steric and electrostatic) provides baseline information necessary to interpret the AFM height image in liquid. Analysis of the film thickness distribution shows that the height of the DNA strands depends on both the DNA strand length (15-35 base pairs) and the environment (air, liquid). In air, longer strands lay down onto gold surface whereas the charge reversal of gold in liquid causes a repulsion of longer strands, which stand up.
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Affiliation(s)
- Guillaume Legay
- Laboratoire de Physique, UMR CNRS 5027, Université de Bourgogne, BP 47870, 9 Rue A. Savary, 21078 Dijon Cedex, France
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36
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37
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Fabrication of piezoresistive microcantilever using surface micromachining technique for biosensors. Ultramicroscopy 2005. [DOI: 10.1016/j.ultramic.2005.06.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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38
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Calleja M, Nordström M, Alvarez M, Tamayo J, Lechuga LM, Boisen A. Highly sensitive polymer-based cantilever-sensors for DNA detection. Ultramicroscopy 2005; 105:215-22. [PMID: 16051438 DOI: 10.1016/j.ultramic.2005.06.039] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2004] [Revised: 01/12/2005] [Indexed: 11/18/2022]
Abstract
We present a technology for the fabrication of cantilever arrays aimed to develop an integrated biosensor microsystem. The fabrication process is based on spin coating of the photosensitive polymer and near-ultraviolet exposure. Arrays of up to 33 microcantilevers are fabricated in the novel polymer material SU-8. The low Young's modulus of the polymer, 40 times lower than that of silicon, enables to improve the sensitivity of the sensor device for target detection. The mechanical properties of SU-8 cantilevers, such as spring constant, resonant frequency and quality factor are characterized as a function of the dimensions and the medium. The devices have been tested for measurement of the adsorption of single stranded DNA and subsequent interstitial adsorption of lateral spacer molecules. We demonstrate that sensitivity is enhanced by a factor of six compared to that of commercial silicon nitride cantilevers.
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Affiliation(s)
- M Calleja
- Biosensors Group, Nacional Center of Microelectronics (CNM-CSIC), Isaac Newton 8, Tres Cantos, E-28760 Madrid, Spain.
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39
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Wee KW, Kang GY, Park J, Kang JY, Yoon DS, Park JH, Kim TS. Novel electrical detection of label-free disease marker proteins using piezoresistive self-sensing micro-cantilevers. Biosens Bioelectron 2005; 20:1932-8. [PMID: 15741060 DOI: 10.1016/j.bios.2004.09.023] [Citation(s) in RCA: 203] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2004] [Revised: 08/25/2004] [Accepted: 09/20/2004] [Indexed: 11/26/2022]
Abstract
We report an electro-mechanical biosensor for electrical detection of proteins with disease markers using self-sensing piezoresistive micro-cantilevers. Electrical detection, via surface stress changes, of antigen-antibody (Ag-Ab) specific binding was accomplished through a direct nano-mechanical response of micro-fabricated self-sensing micro-cantilevers. A piezoresistive sensor measures the film resistance variation with respect to surface stress caused by biomolecules specific binding. When specific binding occurred on a functionalized Au surface, surface stress was induced throughout the cantilever, resulting in cantilever bending and resistance change of the piezoresistive layer. The cantilever biosensors were used for the detection of prostate specific antigen (PSA) and C-reactive proteins (CRP), which are a specific marker of prostate cancer and cardiac disease. From the above experiment, it was revealed that the sensor output voltage was proportional to the injected antigen concentration (without antigen, 10 ng/ml, 100 ng/ml, 1 microg/ml). PSA and CRP antibodies were found to be very specific for their antigens, respectively. This indicated that the self-sensing micro-cantilever approach is beneficial for detecting disease markers, and our piezoresistive micro-cantilever sensor system is applicable to miniaturized biosensor systems.
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Affiliation(s)
- Kyung Wook Wee
- Microsystem Research Center, Korea Institute of Science and Technology (KIST), Seoul 136-791, Republic of Korea
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