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Oliveira SC, Soares S, Rodrigues ACM, Gonçalves BV, Soares AMVM, Santos N, Kumar S, Almeida P, Marques C. Optical fiber immunosensors based on surface plasmon resonance for the detection of Escherichia coli. OPTICS EXPRESS 2024; 32:10077-10092. [PMID: 38571228 DOI: 10.1364/oe.518723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 02/10/2024] [Indexed: 04/05/2024]
Abstract
Every year, millions of people suffer some form of illness associated with the consumption of contaminated food. Escherichia coli (E. coli), found in the intestines of humans and other animals, is commonly associated with various diseases, due to the existence of pathogenic strains. Strict monitoring of food products for human consumption is essential to ensure public health, but traditional cell culture-based methods are associated with long waiting times and high costs. New approaches must be developed to achieve cheap, fast, and on-site monitoring. Thus, in this work, we developed optical fiber sensors based on surface plasmon resonance. Gold and cysteamine-coated fibers were functionalized with anti-E. coli antibody and tested using E. coli suspensions with concentrations ranging from 1 cell/mL to 105 cells/mL. An average logarithmic sensitivity of 0.21 ± 0.01 nm/log(cells/mL) was obtained for three independent assays. An additional assay revealed that including molybdenum disulfide resulted in an increase of approximately 50% in sensitivity. Specificity and selectivity were also evaluated, and the sensors were used to analyze contaminated water samples, which verified their promising applicability in the aquaculture field.
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2
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Juste-Dolz A, Fernández E, Micó G, Bru LA, Muñoz P, Avella-Oliver M, Pastor D, Maquieira Á. Surface Bragg gratings of proteins patterned on integrated waveguides for (bio)chemical analysis. Mikrochim Acta 2023; 191:63. [PMID: 38157073 DOI: 10.1007/s00604-023-06124-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/23/2023] [Indexed: 01/03/2024]
Abstract
The incorporation of biomacromolecules onto silicon waveguiding microstructures constitutes a growing trend that pushes towards compact and miniaturized biosensing systems. This paper presents the integration of one-dimensional periodic nanostructures of proteins on the surface of micrometric silicon waveguides for transducing binding events between biomacromolecules. The study demonstrates this new bioanalytical principle by experimental results and theoretical calculations, and proves that rib waveguides (1--1.6-µm width) together with protein gratings (495--515-nm period) display suitable spectral responses for this optical biosensing system. Protein assemblies of bovine serum albumin are fabricated on the surface of silicon nitride waveguides, characterized by electron microscopy, and their response is measured by optical frequency domain reflectometry along the fabrication process and the subsequent stages of the biorecognition assays. Detection and quantification limits of 0.3 and 3.7 µg·mL-1, respectively, of specific antibodies are inferred from experimental dose-response curves. Among other interesting features, the results of this study point towards new miniaturized and integrated sensors for label-free bioanalysis.
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Affiliation(s)
- Augusto Juste-Dolz
- Instituto Interuniversitario de Investigación de Reconocimiento Molecular y Desarrollo Tecnológico (IDM), Universitat Politècnica de València, Universitat de València, 46022, Valencia, Spain
| | - Estrella Fernández
- Instituto Interuniversitario de Investigación de Reconocimiento Molecular y Desarrollo Tecnológico (IDM), Universitat Politècnica de València, Universitat de València, 46022, Valencia, Spain
| | - Gloria Micó
- Photonics Research Labs, ITEAM, Universitat Politècnica de València, 46022, Valencia, Spain
| | - Luis A Bru
- Photonics Research Labs, ITEAM, Universitat Politècnica de València, 46022, Valencia, Spain
| | - Pascual Muñoz
- Photonics Research Labs, ITEAM, Universitat Politècnica de València, 46022, Valencia, Spain
| | - Miquel Avella-Oliver
- Instituto Interuniversitario de Investigación de Reconocimiento Molecular y Desarrollo Tecnológico (IDM), Universitat Politècnica de València, Universitat de València, 46022, Valencia, Spain.
- Departamento de Química, Universitat Politècnica de València, 46022, Valencia, Spain.
| | - Daniel Pastor
- Photonics Research Labs, ITEAM, Universitat Politècnica de València, 46022, Valencia, Spain.
| | - Ángel Maquieira
- Instituto Interuniversitario de Investigación de Reconocimiento Molecular y Desarrollo Tecnológico (IDM), Universitat Politècnica de València, Universitat de València, 46022, Valencia, Spain.
- Departamento de Química, Universitat Politècnica de València, 46022, Valencia, Spain.
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Dey TK, Trono C, Biswas P, Giannetti A, Basumallick N, Baldini F, Bandyopadhyay S, Tombelli S. Biosensing by Polymer-Coated Etched Long-Period Fiber Gratings Working near Mode Transition and Turn-around Point. BIOSENSORS 2023; 13:731. [PMID: 37504129 PMCID: PMC10377345 DOI: 10.3390/bios13070731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/10/2023] [Accepted: 07/12/2023] [Indexed: 07/29/2023]
Abstract
A methodology to enhance the sensitivity of long-period fiber gratings (LPFGs) based on the combination of three different enhancement approaches is presented; the methods here adopted are the working near mode transition (MT) of a cladding mode (CM), working near the turn-around point of a CM and the enhancement of the evanescent field of CMs by reducing the cladding diameter or by increasing the order number of CMs. In order to combine these enhancement methodologies, an electrostatic self-assembly (ESA) process was used to deposit a polymeric overlay, with a chosen thickness, onto the etched fiber. The add-layer sensitivity of the sensor was theoretically calculated, and the demonstration of the real applicability of the developed LPFG as a biosensor was performed by means of an IgG/anti-IgG immunoassay in human serum in a thermostated microfluidic system. The limits of detection (LODs) calculated by following different procedures (three times the standard deviation of the blank and the mean value of the residuals) were 6.9 × 10-8 µg/mL and 4.5 × 10-6 µg/mL, respectively. The calculated LODs demonstrate the effectiveness of the applied methodology for sensitivity enhancement.
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Affiliation(s)
- Tanoy Kumar Dey
- Central Glass and Ceramic Research Institute, CSIR-CGCRI, 196 Raja S C Mullick Road, Kolkata 700032, India
| | - Cosimo Trono
- Istituto di Fisica Applicata "Nello Carrara", CNR-IFAC, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
| | - Palas Biswas
- Central Glass and Ceramic Research Institute, CSIR-CGCRI, 196 Raja S C Mullick Road, Kolkata 700032, India
| | - Ambra Giannetti
- Istituto di Fisica Applicata "Nello Carrara", CNR-IFAC, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
| | - Nandini Basumallick
- Central Glass and Ceramic Research Institute, CSIR-CGCRI, 196 Raja S C Mullick Road, Kolkata 700032, India
| | - Francesco Baldini
- Istituto di Fisica Applicata "Nello Carrara", CNR-IFAC, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
| | - Somnath Bandyopadhyay
- Central Glass and Ceramic Research Institute, CSIR-CGCRI, 196 Raja S C Mullick Road, Kolkata 700032, India
| | - Sara Tombelli
- Istituto di Fisica Applicata "Nello Carrara", CNR-IFAC, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
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4
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Al-Hamd RK, Al-Janabi A. Evaluation of the laser wavelength role on tooth bleaching in terms of color change, roughness, and microhardness with pulpal rapid temperature monitoring: an in vitro study. APPLIED OPTICS 2023; 62:5475-5486. [PMID: 37706865 DOI: 10.1364/ao.494591] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 06/16/2023] [Indexed: 09/15/2023]
Abstract
This in-vitro study evaluates the efficacy of the teeth bleaching approach using different laser wavelengths (405 nm blue diode, 940 nm infrared diode, and Er,Cr:YSGG 2780 nm lasers) in comparison to the conventional method using light-emitting diode (LED) sources (420-480) nm. Eighty caries-free sound human premolars were randomly divided into four groups (N=20). Each group received a different bleaching procedure. Then each group was further subdivided into two subgroups (N=10) stained with different solutions. The pulp chamber temperature rise was recorded using an optical fiber sensor with a novel design and fabrication. The color was analyzed using a digital spectrophotometer. Five samples of each subgroup were tested for surface roughness, while the others were tested for Vickers microhardness. The bleaching process with a short wavelength 405 nm blue diode laser showed the best results for the shade, with a minimum pulpal temperature increase indicating no possible necrosis and hence maintaining tooth vitality. Additionally, a remarkable reduction in bleaching time was achieved compared to the conventional approach. This process also yielded the highest color change (Δ E) and increased microhardness, with no noticeable change to the tooth roughness. The 405 nm blue diode laser applied for bleaching showed the best bleaching activity against tested stains and negligible pulpal temperature rise with a noticeable reduction in the bleaching time. The proposed novel method to measure temperature change could be used to develop a promising smart sensor for quick, effective, repeatable, and in-situ monitoring of human body temperature.
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5
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Potdar RP, Khollam YB, Shaikh SF, Raut RW, Pandit B, More PS. Evanescent wave sensor for potassium ion detection with special reference to agricultural application. J Photochem Photobiol A Chem 2023. [DOI: 10.1016/j.jphotochem.2023.114707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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6
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Chang YH, Tsai SY, Chow CW, Wang CC, Tsai DC, Liu Y, Yeh CH. Unmanned-aerial-vehicle based optical camera communication system using light-diffusing fiber and rolling-shutter image-sensor. OPTICS EXPRESS 2023; 31:18670-18679. [PMID: 37381574 DOI: 10.1364/oe.492547] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 04/24/2023] [Indexed: 06/30/2023]
Abstract
We put forward and demonstrate a light-diffusing fiber equipped unmanned-aerial-vehicle (UAV) to provide a large field-of-view (FOV) optical camera communication (OCC) system. The light-diffusing fiber can act as a bendable, lightweight, extended and large FOV light source for the UAV-assisted optical wireless communication (OWC). During UAV flying, the light-diffusing fiber light source could be tilted or bended; hence, offering large FOV as well as supporting large receiver (Rx) tilting angle are particularly important for the UAV-assisted OWC systems. To improve the transmission capacity of the OCC system, one method based on the camera shutter mechanism, which is known as rolling-shuttering is utilized. The rolling-shuttering method makes use of the feature of complementary-metal-oxide-semiconductor (CMOS) image sensor to extract signal pixel-row by pixel-row. The data rate can be significantly increased since the capture start time for each pixel-row is different. As the light-diffusing fiber is thin and occupies only a few pixels in the CMOS image frame, Long-short-term-memory neural-network (LSTM-NN) is used to enhance the rolling-shutter decoding. Experimental results show that the light-diffusing fiber can satisfactorily act as an "omnidirectional optical antenna" providing wide FOVs and 3.6 kbit/s can be achieved, accomplishing the pre-forward error correction bit-error-rate (pre-FEC BER = 3.8 × 10-3).
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7
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Xu H, Fu Z, Wei Y. Optimization of deliquescence-proof perovskite-like Cs 3ErF 6 phosphor and dual-mode luminescent intensity ratio thermometry. OPTICS EXPRESS 2023; 31:9123-9134. [PMID: 36860011 DOI: 10.1364/oe.485500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
The susceptibility of Cs-based fluorides to deliquescence has led to the fact that lanthanide-doped Cs-based fluorides and their related applications have hardly been reported. Herein, the method to solve the deliquescence of Cs3ErF6 and its excellent temperature measurement performance were discussed in this work. Initially, the soaking experiment of Cs3ErF6 found that water had irreversible damage to the crystallinity of Cs3ErF6. Subsequently, the luminescent intensity was ensured by the successful isolation of Cs3ErF6 from the deliquescence of vapor by the silicon rubber sheet encapsulation at room temperature. In addition, we also removed moisture by heating samples to obtain temperature-dependent spectra. According to spectral results, two luminescent intensity ratio (LIR) temperature sensing modes were designed. The LIR mode which can quickly respond to temperature parameters by monitoring single band Stark level emission named as "rapid mode". The maximum sensitivity of 7.362%K-1 can be obtained in another "ultra-sensitive mode" thermometer based on the non-thermal coupling energy levels. This work will focus on the deliquescence effect of Cs3ErF6 and the feasibility of silicone rubber encapsulation. At the same time, a dual-mode LIR thermometer is designed for different situations.
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8
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Lobry M, Guyot C, Kinet D, Chah K, Caucheteur C. Plasmonic biosensing with tilted fiber Bragg gratings interrogated using a 512-pixel spectrometer. OPTICS LETTERS 2023; 48:976-979. [PMID: 36790993 DOI: 10.1364/ol.476445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Plasmonic tilted fiber Bragg gratings (TFBGs) are very efficient for fast, accurate, and minimally invasive biosensing. Their transmitted amplitude spectrum is a dense comb of narrowband cladding mode resonances (full width at half maximum < 1 nm) that is usually demodulated using highly resolved (wavelength resolution < 10 pm) devices. This work demonstrates the possibility of using a coarsely resolved spectrometer (166 pm) to read out the amplitude spectrum of a gold-coated TFBG. A refined analysis of the spectral content has allowed us to develop signal processing that provides a refractometric sensitivity of 2656 nm/RIU. This is a fivefold improvement compared to previously reported read-out techniques. Biosensing has then been successfully implemented with gold-coated TFBGs implemented in reflection mode for the detection of insulin, with specific antibodies grafted on the gold surface. Our experimental work is a first step toward the industrialization of the FBG technology, as it opens the door to fast parallel biosensing, profiting from the multiple sensing channels (up to 64) of the interrogator and its high processing speed (repetition rate up to 3 kHz).
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9
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Szczerska M, Wityk P, Listewnik P. Impact of temperature on optical sensing in biology based on investigation of SARS-CoV-2. JOURNAL OF BIOPHOTONICS 2023; 16:e202200186. [PMID: 36153308 PMCID: PMC9537954 DOI: 10.1002/jbio.202200186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
In this paper, we present an investigation of the influence of the temperature on the sensing of biological samples. We used biofunctionalized microsphere-based fiber-optic sensor to detect immunoglobulin G attached to the sensor head at temperatures relevant in biological research: 5°C, 25°C, and 55°C. The construction of the sensor allowed us to perform measurements in the small amount of solution. The results of our experiment confirm substantial changes in the measured reflected optical power, indicating the need to control the temperature during such measurements. The sensitivity of the sensor used in this research is 8.82 nW/°C. Coefficient R was also calculated and it equals 0.998, which shows good fit between theoretical linear fit and obtained measured data.
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Affiliation(s)
- Małgorzata Szczerska
- Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunications and InformaticsGdańsk University of TechnologyGdańskPoland
| | - Paweł Wityk
- Department of Biopharmaceutics and PharmacodynamicsMedical University of GdańskGdańskPoland
| | - Paulina Listewnik
- Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunications and InformaticsGdańsk University of TechnologyGdańskPoland
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10
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Leal-Junior A, Lopes G, Macedo LC, Duque W, Frizera A, Marques C. Heterogeneous Optical Fiber Sensor System for Temperature and Turbidity Assessment in Wide Range. BIOSENSORS 2022; 12:1041. [PMID: 36421159 PMCID: PMC9688452 DOI: 10.3390/bios12111041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/01/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
This paper presents the development of an optical fiber sensor system for multiparametric assessment of temperature and turbidity in liquid samples. The sensors are based on the combination between fiber Bragg gratings (FBGs), intensity variation and surface plasmon resonance (SPR) sensors. In this case, the intensity variation sensors are capable of detecting turbidity with a resolution of about 0.5 NTU in a limited range between 0.02 NTU and 100 NTU. As the turbidity increases, a saturation trend in the sensor is observed. In contrast, the SPR-based sensor is capable of detecting refractive index (RI) variation. However, RI measurements in the turbidity calibrated samples indicate a significant variation on the RI only when the turbidity is higher than 100 NTU. Thus, the SPR-based sensor is used as a complementary approach for the dynamic range increase of the turbidity assessment, where a linearity and sensitivity of 98.6% and 313.5 nm/RIU, respectively, are obtained. Finally, the FBG sensor is used in the temperature assessment, an assessment which is not only used for water quality assessment, but also in temperature cross-sensitivity mitigation of the SPR sensor. Furthermore, this approach also leads to the possibility of indirect assessment of turbidity through the differences in the heat transfer rates due to the turbidity increase.
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Affiliation(s)
- Arnaldo Leal-Junior
- Graduate Program of Electrical Engineering of Federal, University of Espírito Santo, Vitória 29075-910, Brazil
- Mechanical Engineering Department of Federal, University of Espírito Santo, Vitória 29075-910, Brazil
| | - Guilherme Lopes
- Physics Department & I3N, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Leandro C. Macedo
- Graduate Program of Electrical Engineering of Federal, University of Espírito Santo, Vitória 29075-910, Brazil
| | - Welton Duque
- Graduate Program of Electrical Engineering of Federal, University of Espírito Santo, Vitória 29075-910, Brazil
| | - Anselmo Frizera
- Graduate Program of Electrical Engineering of Federal, University of Espírito Santo, Vitória 29075-910, Brazil
| | - Carlos Marques
- Physics Department & I3N, University of Aveiro, 3810-193 Aveiro, Portugal
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Yang Y, Zhao R, Wang Y, Song D, Jiang B, Guo X, Liu W, Long F, Song H, Hao R. Rapid and universal detection of SARS-CoV-2 and influenza A virus using a reusable dual-channel optic fiber immunosensor. J Med Virol 2022; 94:5325-5335. [PMID: 35859097 PMCID: PMC9349508 DOI: 10.1002/jmv.28015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/12/2022] [Accepted: 07/15/2022] [Indexed: 12/15/2022]
Abstract
Establishment of rapid on-site detection technology capable of concurrently detecting SARS-Cov-2 and influenza A virus is urgent to effectively control the epidemic from these two types of important viruses. Accordingly, we developed a reusable dual-channel optical fiber immunosensor (DOFIS), which utilized the evanescent wave-sensing properties and tandem detection mode of the mobile phase, effectively accelerating the detection process such that it can be completed within 10 min. It could detect the nucleoprotein of multiple influenza A viruses (H1N1, H3N2, and H7N9), as well as the spike proteins of the SARS-CoV-2 Omicron and Delta variants, and could respond to 20 TCID50 /ml SARS-CoV-2 pseudovirus and 100 TCID50 /ml influenza A (A/PR/8/H1N1), presenting lower limit of detection and wider linear range than enzyme-linked immunosorbent assay. The detection results on 26 clinical samples for SARS-CoV-2 demonstrated its specificity (100%) and sensitivity (94%), much higher than the sensitivity of commercial colloidal gold test strip (35%). Particularly, DOFIS might be reused more than 80 times, showing not only cost-saving but also potential in real-time monitoring of the pathogenic viruses. Therefore, this newly-developed DOFIS platform is low cost, simple to operate, and has broad spectrum detection capabilities for SARS-CoV-2 mutations and multiple influenza A strains. It may prove suitable for deployment as a rapid on-site screening and surveillance technique for infectious disease.
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Affiliation(s)
- Yi Yang
- Chinese PLA Center for Disease Control and PreventionBeijingChina
| | - Rongtao Zhao
- Chinese PLA Center for Disease Control and PreventionBeijingChina
| | - Yule Wang
- Chinese PLA Center for Disease Control and PreventionBeijingChina
| | - Dan Song
- School of Environment and Natural ResourcesRenmin University of ChinaBeijingChina
| | - Bo Jiang
- Department of Toxicology and Sanitary Chemistry, School of Public HealthCapital Medical UniversityBeijingChina,Beijing Key Laboratory of Environmental ToxicologyCapital Medical UniversityBeijingChina
| | - Xudong Guo
- Chinese PLA Center for Disease Control and PreventionBeijingChina
| | - Wanying Liu
- Chinese PLA Center for Disease Control and PreventionBeijingChina
| | - Feng Long
- School of Environment and Natural ResourcesRenmin University of ChinaBeijingChina
| | - Hongbin Song
- Chinese PLA Center for Disease Control and PreventionBeijingChina
| | - Rongzhang Hao
- Chinese PLA Center for Disease Control and PreventionBeijingChina,Department of Toxicology and Sanitary Chemistry, School of Public HealthCapital Medical UniversityBeijingChina,Beijing Key Laboratory of Environmental ToxicologyCapital Medical UniversityBeijingChina
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12
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Huang J, Wei F, Cui Y, Hou L, Lin T. Fluorescence immunosensor based on functional nanomaterials and its application in tumor biomarker detection. RSC Adv 2022; 12:31369-31379. [PMID: 36349017 PMCID: PMC9624183 DOI: 10.1039/d2ra04989a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 10/19/2022] [Indexed: 09/29/2023] Open
Abstract
An immunosensor is defined as an analytical device that detects the binding of an antigen to its specific antibody by coupling an immunochemical reaction to the surface of a device called a transducer. Fluorescence immunosensing is one of the most promising immunoassays at present, and has the advantages of simple operation, fast response and high stability. A traditional fluorescence immunosensor often uses an enzyme-labelled antibody as a recognition unit and an organic dye as a fluorescence probe, so it is easily affected by environmental factors with low sensitivity. Nanomaterials have unique photostability, catalytic properties and biocompatibility, which open up a new path for the construction of stable and sensitive fluorescence immunosensors. This paper briefly introduces different kinds of immunosensors and the role of nanomaterials in the construction of immunosensors. The significance of fluorescent immunosensors constructed from functional nanomaterials to detect tumor biomarkers was analyzed, and the strategies to further improve the performance of fluorescent immunosensors and their future development trend were summarized.
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Affiliation(s)
- Juanjuan Huang
- School of Chemistry and Pharmaceutical Science, State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University Guilin 541004 P. R. China
| | - Fenghuang Wei
- School of Chemistry and Pharmaceutical Science, State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University Guilin 541004 P. R. China
| | - Yuling Cui
- Jinan Center for Food and Drug Control Jinan 250102 Shandong China
| | - Li Hou
- School of Chemistry and Pharmaceutical Science, State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University Guilin 541004 P. R. China
| | - Tianran Lin
- School of Chemistry and Pharmaceutical Science, State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University Guilin 541004 P. R. China
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13
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Li M, Singh R, Wang Y, Marques C, Zhang B, Kumar S. Advances in Novel Nanomaterial-Based Optical Fiber Biosensors-A Review. BIOSENSORS 2022; 12:bios12100843. [PMID: 36290980 PMCID: PMC9599727 DOI: 10.3390/bios12100843] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 05/24/2023]
Abstract
This article presents a concise summary of current advancements in novel nanomaterial-based optical fiber biosensors. The beneficial optical and biological properties of nanomaterials, such as nanoparticle size-dependent signal amplification, plasmon resonance, and charge-transfer capabilities, are widely used in biosensing applications. Due to the biocompatibility and bioreceptor combination, the nanomaterials enhance the sensitivity, limit of detection, specificity, and response time of sensing probes, as well as the signal-to-noise ratio of fiber optic biosensing platforms. This has established a practical method for improving the performance of fiber optic biosensors. With the aforementioned outstanding nanomaterial properties, the development of fiber optic biosensors has been efficiently promoted. This paper reviews the application of numerous novel nanomaterials in the field of optical fiber biosensing and provides a brief explanation of the fiber sensing mechanism.
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Affiliation(s)
- Muyang Li
- Shandong Key Laboratory of Optical Communication Science and Technology, School of Physics Science and Information Technology, Liaocheng University, Liaocheng 252059, China
| | - Ragini Singh
- College of Agronomy, Liaocheng University, Liaocheng 252059, China
| | - Yiran Wang
- Shandong Key Laboratory of Optical Communication Science and Technology, School of Physics Science and Information Technology, Liaocheng University, Liaocheng 252059, China
| | - Carlos Marques
- Department of Physics & I3N, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Bingyuan Zhang
- Shandong Key Laboratory of Optical Communication Science and Technology, School of Physics Science and Information Technology, Liaocheng University, Liaocheng 252059, China
| | - Santosh Kumar
- Shandong Key Laboratory of Optical Communication Science and Technology, School of Physics Science and Information Technology, Liaocheng University, Liaocheng 252059, China
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14
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Lobry M, Loyez M, Debliquy M, Chah K, Goormaghtigh E, Caucheteur C. Electro-plasmonic-assisted biosensing of proteins and cells at the surface of optical fiber. Biosens Bioelectron 2022; 220:114867. [DOI: 10.1016/j.bios.2022.114867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/16/2022] [Accepted: 10/27/2022] [Indexed: 11/16/2022]
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15
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Tian Z, Yao Y, Yuan J, Zhang L, Chen NK, Zhang Y, Wang M, Wu Q. Post chemical etching of tapered seven-core fiber sensor for enhanced figure of merit. OPTICS LETTERS 2022; 47:4672-4675. [PMID: 36107060 DOI: 10.1364/ol.469107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
A post chemical etching process to a tapered seven-core fiber (TSCF) is proposed and experimentally demonstrated to effectively adjust the mode profiles of high-order supermodes, aimed to improve the figure of merit (FOM). The experimental results show that the FOM of an etched TSCF is as high as 1431.36 1/RIU, a 7.32-times enhancement compared with that of TSCF without etching, provided the TSCF has the same taper waist diameter of 19.20 µm. The proposed method opens a new, to the best of our knowledge, method for optimizing optical fiber sensor performance.
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Şolomonea BG, Jinga LI, Antohe VA, Socol G, Antohe I. Cadmium Ions' Trace-Level Detection Using a Portable Fiber Optic-Surface Plasmon Resonance Sensor. BIOSENSORS 2022; 12:bios12080573. [PMID: 36004969 PMCID: PMC9405698 DOI: 10.3390/bios12080573] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 05/02/2023]
Abstract
Environmental pollution with cadmium (Cd) is a major concern worldwide, with prolonged exposure to this toxic heavy metal causing serious health problems, such as kidney damage, cancer, or cardiovascular diseases, only to mention a few. Herein, a gold-coated reflection-type fiber optic--surface plasmon resonance (Au-coated FO-SPR) sensor is manufactured and functionalized with (i) bovine serum albumin (BSA), (ii) chitosan, and (iii) polyaniline (PANI), respectively, for the sensitive detection of cadmium ions (Cd2+) in water. Then, the three sensor functionalization strategies are evaluated and compared one at a time. Out of these strategies, the BSA-functionalized FO-SPR sensor is found to be highly sensitive, exhibiting a limit of detection (LOD) for Cd2+ detection at nM level. Moreover, the presence of Cd2+ on the FO-SPR sensor surface was confirmed by the X-ray photoelectron spectroscopy (XPS) technique and also quantified consecutively for all the above-mentioned functionalization strategies. Hence, the BSA-functionalized FO-SPR sensor is sensitive, provides a rapid detection time, and is cheap and portable, with potential applicability for monitoring trace-level amounts of Cd within environmental or potable water.
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Affiliation(s)
- Bianca-Georgiana Şolomonea
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), Atomiştilor Street 409, 077125 Măgurele, Ilfov, Romania; (B.-G.Ş.); (L.-I.J.)
- Faculty of Physics, Research and Development Center for Materials and Electronic & Optoelectronic Devices (MDEO), University of Bucharest, Atomiştilor Street 405, 077125 Măgurele, Ilfov, Romania;
| | - Luiza-Izabela Jinga
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), Atomiştilor Street 409, 077125 Măgurele, Ilfov, Romania; (B.-G.Ş.); (L.-I.J.)
| | - Vlad-Andrei Antohe
- Faculty of Physics, Research and Development Center for Materials and Electronic & Optoelectronic Devices (MDEO), University of Bucharest, Atomiştilor Street 405, 077125 Măgurele, Ilfov, Romania;
- Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCLouvain), Place Croix du Sud 1, B-1348 Louvain-la-Neuve, Belgium
| | - Gabriel Socol
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), Atomiştilor Street 409, 077125 Măgurele, Ilfov, Romania; (B.-G.Ş.); (L.-I.J.)
- Correspondence: (G.S.); (I.A.)
| | - Iulia Antohe
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), Atomiştilor Street 409, 077125 Măgurele, Ilfov, Romania; (B.-G.Ş.); (L.-I.J.)
- Academy of Romanian Scientists (AOSR), Splaiul Independenţei 54, 050094 Bucharest, Romania
- Correspondence: (G.S.); (I.A.)
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17
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Pandey PS, Raghuwanshi SK, Shadab A, Ansari MTI, Tiwari UK, Kumar S. SPR Based Biosensing Chip for COVID-19 Diagnosis-A Review. IEEE SENSORS JOURNAL 2022; 22:13800-13810. [PMID: 36346093 DOI: 10.1109/jsen.2021.3133007] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/06/2022] [Accepted: 06/06/2022] [Indexed: 05/24/2023]
Abstract
Surface Plasmon Resonance (SPR) techniques are highly accurate in detecting biomolecular like blood group measurement, food adulteration, milk adulteration and recently developing as a rapid detection for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. In order to validate the clinical diagnosis, Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) of nasopharyngeal swabs has been utilized, which is time consuming and expensive. For fast and accurate detection of the SARS-CoV-2 virus, SPR based biosensing chips are described in this review article. SPR sensors have the potential to be employed for fast, accurate, and portable SARS-CoV-2 virus diagnosis. To combat the SARS-CoV-2 pandemic, there is considerable interest in creating innovative biosensors that are quick, reliable, and sensitive for COVID-19 diagnosis.
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Affiliation(s)
- Purnendu Shekhar Pandey
- Optical Fiber Sensor LaboratoryDepartment of Electronics EngineeringIndian Institute of Technology (Indian School of Mines) Dhanbad Dhanbad Jharkhand 826004 India
| | - Sanjeev Kumar Raghuwanshi
- Department of Electronics EngineeringIndian Institute of Technology (Indian School of Mines) Dhanbad Dhanbad Jharkhand 826004 India
| | - Azhar Shadab
- Optical Fiber Sensor LaboratoryDepartment of Electronics EngineeringIndian Institute of Technology (Indian School of Mines) Dhanbad Dhanbad Jharkhand 826004 India
| | - Md Tauseef Iqbal Ansari
- Optical Fiber Sensor LaboratoryDepartment of Electronics EngineeringIndian Institute of Technology (Indian School of Mines) Dhanbad Dhanbad Jharkhand 826004 India
| | - Umesh Kumar Tiwari
- Advanced Materials and Sensors DivisionCentral Scientific Instruments Organisation (CSIO) Chandigarh 160030 India
| | - Santosh Kumar
- Shandong Key Laboratory of Optical Communication Science and Technology, School of Physics Science and Information TechnologyLiaocheng University Liaocheng 252059 China
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18
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Pandey PS, Raghuwanshi SK, Shadab A, Ansari MTI, Tiwari UK, Kumar S. SPR Based Biosensing Chip for COVID-19 Diagnosis-A Review. IEEE SENSORS JOURNAL 2022; 22:13800-13810. [PMID: 36346093 PMCID: PMC9423036 DOI: 10.1109/jsen.2022.3181423] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/06/2022] [Accepted: 06/06/2022] [Indexed: 05/13/2023]
Abstract
Surface Plasmon Resonance (SPR) techniques are highly accurate in detecting biomolecular like blood group measurement, food adulteration, milk adulteration and recently developing as a rapid detection for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. In order to validate the clinical diagnosis, Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) of nasopharyngeal swabs has been utilized, which is time consuming and expensive. For fast and accurate detection of the SARS-CoV-2 virus, SPR based biosensing chips are described in this review article. SPR sensors have the potential to be employed for fast, accurate, and portable SARS-CoV-2 virus diagnosis. To combat the SARS-CoV-2 pandemic, there is considerable interest in creating innovative biosensors that are quick, reliable, and sensitive for COVID-19 diagnosis.
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Affiliation(s)
- Purnendu Shekhar Pandey
- Optical Fiber Sensor LaboratoryDepartment of Electronics EngineeringIndian Institute of Technology (Indian School of Mines) Dhanbad Dhanbad Jharkhand 826004 India
| | - Sanjeev Kumar Raghuwanshi
- Department of Electronics EngineeringIndian Institute of Technology (Indian School of Mines) Dhanbad Dhanbad Jharkhand 826004 India
| | - Azhar Shadab
- Optical Fiber Sensor LaboratoryDepartment of Electronics EngineeringIndian Institute of Technology (Indian School of Mines) Dhanbad Dhanbad Jharkhand 826004 India
| | - Md Tauseef Iqbal Ansari
- Optical Fiber Sensor LaboratoryDepartment of Electronics EngineeringIndian Institute of Technology (Indian School of Mines) Dhanbad Dhanbad Jharkhand 826004 India
| | - Umesh Kumar Tiwari
- Advanced Materials and Sensors DivisionCentral Scientific Instruments Organisation (CSIO) Chandigarh 160030 India
| | - Santosh Kumar
- Shandong Key Laboratory of Optical Communication Science and Technology, School of Physics Science and Information TechnologyLiaocheng University Liaocheng 252059 China
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19
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Dang H, Zhang Y, Qiao Y, Li J. Refractive Index and Temperature Sensing Performance of Microfiber Modified by UV Glue Distributed Nanoparticles. Polymers (Basel) 2022; 14:polym14122425. [PMID: 35746001 PMCID: PMC9228800 DOI: 10.3390/polym14122425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/04/2022] [Accepted: 06/13/2022] [Indexed: 02/01/2023] Open
Abstract
Dielectric materials with high refractive index have been widely studied to develop novel photonic devices for modulating optical signals. In this paper, the microfibers were modified by silicon nanoparticles (NPs) and silver NPs mixed in UV glue with ultra-low refractive index, respectively, whose corresponding optical and sensing properties have been studied and compared. The influence from either the morphological parameters of microfiber or the concentration of NPs on the refractive index sensing performance of microfiber has been investigated. The refractive index sensitivities for the microfiber tapers elaborated with silver NPs and silicon NPs were experimentally demonstrated to be 1382.3 nm/RIU and 1769.7 nm/RIU, respectively. Furthermore, the proposed microfiber was encapsulated in one cut of capillary to develop a miniature temperature probe, whose sensitivity was determined as 2.08 nm/°C, ranging from 28 °C to 43 °C.
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Affiliation(s)
- Hongtao Dang
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Electronic Information, Xijing University, Xi’an 710123, China; (H.D.); (Y.Z.); (Y.Q.)
| | - Yan Zhang
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Electronic Information, Xijing University, Xi’an 710123, China; (H.D.); (Y.Z.); (Y.Q.)
| | - Yukun Qiao
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Electronic Information, Xijing University, Xi’an 710123, China; (H.D.); (Y.Z.); (Y.Q.)
| | - Jin Li
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Electronic Information, Xijing University, Xi’an 710123, China; (H.D.); (Y.Z.); (Y.Q.)
- College of Information Science and Engineering, Northeastern University, Shenyang 110819, China
- Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao 066004, China
- Correspondence:
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A method for the controllable fabrication of optical fiber-based localized surface plasmon resonance sensors. Sci Rep 2022; 12:9566. [PMID: 35688862 PMCID: PMC9187767 DOI: 10.1038/s41598-022-13707-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 05/26/2022] [Indexed: 12/12/2022] Open
Abstract
Optical fiber-based Localized Surface Plasmon Resonance (OF-LSPR) biosensors have emerged as an ultra-sensitive miniaturized tool for a great variety of applications. Their fabrication by the chemical immobilization of gold nanoparticles (AuNPs) on the optic fiber end face is a simple and versatile method. However, it can render poor reproducibility given the number of parameters that influence the binding of the AuNPs. In order to develop a method to obtain OF-LSPR sensors with high reproducibility, we studied the effect that factors such as temperature, AuNPs concentration, fiber core size and time of immersion had on the number and aggregation of AuNPs on the surface of the fibers and their resonance signal. Our method consisted in controlling the deposition of a determined AuNPs density on the tip of the fiber by measuring its LSPR signal (or plasmonic signal, Sp) in real-time. Sensors created thus were used to measure changes in the refractive index of their surroundings and the results showed that, as the number of AuNPs on the probes increased, the changes in the Sp maximum values were ever lower but the wavelength shifts were higher. These results highlighted the relevance of controlling the relationship between the sensor composition and its performance.
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21
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Soares MS, Silva LCB, Vidal M, Loyez M, Facão M, Caucheteur C, Segatto MEV, Costa FM, Leitão C, Pereira SO, Santos NF, Marques CAF. Label-free plasmonic immunosensor for cortisol detection in a D-shaped optical fiber. BIOMEDICAL OPTICS EXPRESS 2022; 13:3259-3274. [PMID: 35781957 PMCID: PMC9208605 DOI: 10.1364/boe.456253] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/22/2022] [Accepted: 03/28/2022] [Indexed: 05/02/2023]
Abstract
Measuring cortisol levels as a stress biomarker is essential in many medical conditions associated with a high risk of metabolic syndromes such as anxiety and cardiovascular diseases, among others. One technology that has a growing interest in recent years is fiber optic biosensors that enable ultrasensitive cortisol detection. Such interest is allied with progress being achieved in basic interrogation, accuracy improvements, and novel applications. The development of improved cortisol monitoring, with a simplified manufacturing process, high reproducibility, and low cost, are challenges that these sensing mechanisms still face, and for which solutions are still needed. In this paper, a comprehensive characterization of a D-shaped fiber optic immunosensor for cortisol detection based on surface plasmon resonance (SPR) enabled by gold coating is reported. Specifically, the sensor instrumentation and fabrication processes are discussed in detail, and a simulation with its complete mathematical formalism is also presented. Moreover, experimental cortisol detection tests were performed for a detection range of 0.01 to 100 ng/mL, attaining a logarithmic sensitivity of 0.65 ± 0.02 nm/log(ng/mL) with a limit of detection (LOD) of 1.46 ng/mL. Additionally, an investigation of signal processing is also discussed, with the main issues addressed in order to highlight the best way to extract the sensing information from the spectra measured with a D-shaped sensor.
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Affiliation(s)
- Maria S. Soares
- i3N, Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Luís C. B. Silva
- Electrical Engineering Dept., Federal University of Espírito Santo, Fernando Ferrari Avenue, 29075-910, Brazil
| | - Miguel Vidal
- i3N, Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Médéric Loyez
- University of Mons, Boulevard Dolez 31, 7000 Mons, Belgium
| | - Margarida Facão
- i3N, Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal
| | | | - Marcelo E. V. Segatto
- Electrical Engineering Dept., Federal University of Espírito Santo, Fernando Ferrari Avenue, 29075-910, Brazil
| | - Florinda M. Costa
- i3N, Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Cátia Leitão
- i3N, Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Sónia O. Pereira
- i3N, Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Nuno F. Santos
- i3N, Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal
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22
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Vidal M, Soares MS, Loyez M, Costa FM, Caucheteur C, Marques C, Pereira SO, Leitão C. Relevance of the Spectral Analysis Method of Tilted Fiber Bragg Grating-Based Biosensors: A Case-Study for Heart Failure Monitoring. SENSORS 2022; 22:s22062141. [PMID: 35336312 PMCID: PMC8954114 DOI: 10.3390/s22062141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/23/2022] [Accepted: 03/08/2022] [Indexed: 01/16/2023]
Abstract
Optical fiber technology has rapidly progressed over the years, providing valuable benefits for biosensing purposes such as sensor miniaturization and the possibility for remote and real-time monitoring. In particular, tilted fiber Bragg gratings (TFBGs) are extremely sensitive to refractive index variations taking place on their surface. The present work comprises a case-study on the impact of different methods of analysis applied to decode spectral variations of bare and plasmonic TFBGs during the detection of N-terminal B-type natriuretic peptide (NT-proBNP), a heart failure biomarker, namely by following the most sensitive mode, peaks of the spectral envelopes, and the envelopes’ crossing point and area. Tracking the lower envelope resulted in the lowest limits of detection (LOD) for bare and plasmonic TFBGs, namely, 0.75 ng/mL and 0.19 ng/mL, respectively. This work demonstrates the importance of the analysis method on the outcome results, which is crucial to attain the most reliable and sensitive method with lower LOD sensors. Furthermore, it makes the scientific community aware to take careful attention when comparing the performance of different biosensors in which different analysis methods were used.
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Affiliation(s)
- Miguel Vidal
- Physics Department & I3N, University of Aveiro, 3810-193 Aveiro, Portugal; (M.V.); (M.S.S.); (F.M.C.); (C.M.); (S.O.P.)
| | - Maria Simone Soares
- Physics Department & I3N, University of Aveiro, 3810-193 Aveiro, Portugal; (M.V.); (M.S.S.); (F.M.C.); (C.M.); (S.O.P.)
| | - Médéric Loyez
- Electromagnetism and Telecommunication Department, University of Mons, 31 Bld Dolez, 7000 Mons, Belgium; (M.L.); (C.C.)
| | - Florinda M. Costa
- Physics Department & I3N, University of Aveiro, 3810-193 Aveiro, Portugal; (M.V.); (M.S.S.); (F.M.C.); (C.M.); (S.O.P.)
| | - Christophe Caucheteur
- Electromagnetism and Telecommunication Department, University of Mons, 31 Bld Dolez, 7000 Mons, Belgium; (M.L.); (C.C.)
| | - Carlos Marques
- Physics Department & I3N, University of Aveiro, 3810-193 Aveiro, Portugal; (M.V.); (M.S.S.); (F.M.C.); (C.M.); (S.O.P.)
| | - Sónia O. Pereira
- Physics Department & I3N, University of Aveiro, 3810-193 Aveiro, Portugal; (M.V.); (M.S.S.); (F.M.C.); (C.M.); (S.O.P.)
| | - Cátia Leitão
- Physics Department & I3N, University of Aveiro, 3810-193 Aveiro, Portugal; (M.V.); (M.S.S.); (F.M.C.); (C.M.); (S.O.P.)
- Correspondence:
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