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Gong C, Yang X, Tang SJ, Zhang QQ, Wang Y, Liu YL, Chen YC, Peng GD, Fan X, Xiao YF, Rao YJ, Gong Y. Submonolayer biolasers for ultrasensitive biomarker detection. LIGHT, SCIENCE & APPLICATIONS 2023; 12:292. [PMID: 38052775 DOI: 10.1038/s41377-023-01335-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 10/18/2023] [Accepted: 11/12/2023] [Indexed: 12/07/2023]
Abstract
Biomarker detection is key to identifying health risks. However, designing sensitive and single-use biosensors for early diagnosis remains a major challenge. Here, we report submonolayer lasers on optical fibers as ultrasensitive and disposable biosensors. Telecom optical fibers serve as distributed optical microcavities with high Q-factor, great repeatability, and ultralow cost, which enables whispering-gallery laser emission to detect biomarkers. It is found that the sensing performance strongly depends on the number of gain molecules. The submonolayer lasers obtained a six-order-of-magnitude improvement in the lower limit of detection (LOD) when compared to saturated monolayer lasers. We further achieve an ultrasensitive immunoassay for a Parkinson's disease biomarker, alpha-synuclein (α-syn), with a lower LOD of 0.32 pM in serum, which is three orders of magnitude lower than the α-syn concentration in the serum of Parkinson's disease patients. Our demonstration of submonolayer biolaser offers great potentials in high-throughput clinical diagnosis with ultimate sensitivity.
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Affiliation(s)
- Chaoyang Gong
- Key Laboratory of Optical Fiber Sensing and Communications (Ministry of Education of China), School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, China
- Key Laboratory of Optoelectronic Technology and Systems (Ministry of Education of China), School of Optoelectronic Engineering, Chongqing University, Chongqing, 400044, China
| | - Xi Yang
- Key Laboratory of Optical Fiber Sensing and Communications (Ministry of Education of China), School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, China
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Centre for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China
| | - Shui-Jing Tang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Centre for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China
| | - Qian-Qian Zhang
- Key Laboratory of Optical Fiber Sensing and Communications (Ministry of Education of China), School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, China
| | - Yanqiong Wang
- Key Laboratory of Optical Fiber Sensing and Communications (Ministry of Education of China), School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, China
| | - Yi-Ling Liu
- Key Laboratory of Optical Fiber Sensing and Communications (Ministry of Education of China), School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, China
| | - Yu-Cheng Chen
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Gang-Ding Peng
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Xudong Fan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Yun-Feng Xiao
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Centre for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China.
| | - Yun-Jiang Rao
- Key Laboratory of Optical Fiber Sensing and Communications (Ministry of Education of China), School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, China.
- Research Centre for Optical Fiber Sensing, Zhejiang Laboratory, Hangzhou, Zhejiang, 310000, China.
| | - Yuan Gong
- Key Laboratory of Optical Fiber Sensing and Communications (Ministry of Education of China), School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, China.
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Demonstration of intracellular real-time molecular quantification via FRET-enhanced optical microcavity. Nat Commun 2022; 13:6685. [PMID: 36335126 PMCID: PMC9637138 DOI: 10.1038/s41467-022-34547-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 10/24/2022] [Indexed: 11/08/2022] Open
Abstract
Single cell analysis is crucial for elucidating cellular diversity and heterogeneity as well as for medical diagnostics operating at the ultimate detection limit. Although superbly sensitive biosensors have been developed using the strongly enhanced evanescent fields provided by optical microcavities, real-time quantification of intracellular molecules remains challenging due to the extreme low quantity and limitations of the current techniques. Here, we introduce an active-mode optical microcavity sensing stage with enhanced sensitivity that operates via Förster resonant energy transferring (FRET) mechanism. The mutual effects of optical microcavity and FRET greatly enhances the sensing performance by four orders of magnitude compared to pure Whispering gallery mode (WGM) microcavity sensing system. We demonstrate distinct sensing mechanism of FRET-WGM from pure WGM. Predicted lasing wavelengths of both donor and acceptor by theoretical calculations are in perfect agreement with the experimental data. The proposed sensor enables quantitative molecular analysis at single cell resolution, and real-time monitoring of intracellular molecules over extended periods while maintaining the cell viability. By achieving high sensitivity at single cell level, our approach provides a path toward FRET-enhanced real-time quantitative analysis of intracellular molecules.
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Zheng L, Zhi M, Chan Y, Khan SA. Multi-color lasing in chemically open droplet cavities. Sci Rep 2018; 8:14088. [PMID: 30237486 PMCID: PMC6147796 DOI: 10.1038/s41598-018-32596-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/10/2018] [Indexed: 11/09/2022] Open
Abstract
In this paper, we demonstrate FRET-based multicolor lasing within chemically open droplet cavities that allow online modulation of the gain medium composition. To do this, we generated monodisperse microfluidic droplets loaded with coumarin 102 (donor), where the spherical droplets acted as whispering gallery mode (WGM) optical cavities in which coumarin 102 lasing (~ 470 nm) was observed. The lasing color was switched from blue to orange by the introduction of a second dye (acceptor, rhodamine 6 G) into the flowing droplet cavities; subsequent lasing from rhodamine 6 G (~ 590 nm) was observed together with the complete absence of coumarin 102 emission. The ability to control color switching online within the same droplet cavity enables sequential detection of multiple target molecules within or around the cavity. As a demonstration of this concept, we show how the presence of FITC-Dextran and methylene blue (MB) in the medium surrounding the lasing droplets can be sequentially detected by the blue and orange laser respectively. The method is simple and can be extended to a range of water-soluble dyes, thus enabling a wide spectral range for the lasing with the use of a single pump laser source.
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Affiliation(s)
- Lu Zheng
- Department of Chemical and Biomolecular Engineering, 3 Engineering Drive 3, National University of Singapore, Singapore, 117582, Singapore
| | - Min Zhi
- Department of Chemistry, 3 Science Drive 3, National University of Singapore, Singapore, 117543, Singapore
| | - Yinthai Chan
- Department of Chemistry, 3 Science Drive 3, National University of Singapore, Singapore, 117543, Singapore.
| | - Saif A Khan
- Department of Chemical and Biomolecular Engineering, 3 Engineering Drive 3, National University of Singapore, Singapore, 117582, Singapore.
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Zheng L, Zhi M, Chan Y, Khan SA. Embedding liquid lasers within or around aqueous microfluidic droplets. LAB ON A CHIP 2017; 18:197-205. [PMID: 29184929 DOI: 10.1039/c7lc00701a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In this paper, we demonstrate the incorporation of dye-based liquid lasers within or around flowing aqueous microfluidic droplets. In particular, we use dye solutions in benzyl alcohol, and either disperse an ensemble of small (∼20 μm) lasing droplets within large (∼500 μm) aqueous droplets flowing in a simple glass capillary-based microfluidic device, or 'wrap' a thin (∼10 μm) lasing benzyl alcohol shell around larger (∼560 μm) microfluidic aqueous droplets. We experimentally and theoretically characterize the lasing behavior in both cases, which is supported by whispering-gallery mode (WGM) optical resonances at the droplet interfaces. We showcase a simple application of our method, which highlights the advantages of having embedded, spatially segregated laser sources within a droplet containing a model analyte solution. With this method, each microfluidic droplet now functions not only as an isolated experiment flask, but is also capable of on drop sensing that exploits WGM-based lasing, thus expanding the possibilities for online monitoring of biophysical/biochemical processes and sensitive detection of biomolecules in droplet-based microfluidics.
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Affiliation(s)
- Lu Zheng
- Department of Chemical and Biomolecular Engineering, 3 Engineering Drive 3, National University of Singapore, Singapore 117582, Singapore.
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Designing a Broadband Pump for High-Quality Micro-Lasers via Modified Net Radiation Method. Sci Rep 2016; 6:38576. [PMID: 27924844 PMCID: PMC5141496 DOI: 10.1038/srep38576] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 11/09/2016] [Indexed: 11/09/2022] Open
Abstract
High-quality micro-lasers are key ingredients in non-linear optics, communication, sensing and low-threshold solar-pumped lasers. However, such micro-lasers exhibit negligible absorption of free-space broadband pump light. Recently, this limitation was lifted by cascade energy transfer, in which the absorption and quality factor are modulated with wavelength, enabling non-resonant pumping of high-quality micro-lasers and solar-pumped laser to operate at record low solar concentration. Here, we present a generic theoretical framework for modeling the absorption, emission and energy transfer of incoherent radiation between cascade sensitizer and laser gain media. Our model is based on linear equations of the modified net radiation method and is therefore robust, fast converging and has low complexity. We apply this formalism to compute the optimal parameters of low-threshold solar-pumped lasers. It is revealed that the interplay between the absorption and self-absorption of such lasers defines the optimal pump absorption below the maximal value, which is in contrast to conventional lasers for which full pump absorption is desired. Numerical results are compared to experimental data on a sensitized Nd3+:YAG cavity, and quantitative agreement with theoretical models is found. Our work modularizes the gain and sensitizing components and paves the way for the optimal design of broadband-pumped high-quality micro-lasers and efficient solar-pumped lasers.
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Abstract
Chlorophylls are essential for photosynthesis and also one of the most abundant pigments on earth. Using an optofluidic ring resonator of extremely high Q-factors (>10(7)), we investigated the unique characteristics and underlying mechanism of chlorophyll lasers. Chlorophyll lasers with dual lasing bands at 680 nm and 730 nm were observed for the first time in isolated chlorophyll a (Chla). Particularly, a laser at the 730 nm band was realized in 0.1 mM Chla with a lasing threshold of only 8 μJ mm(-2). Additionally, we observed lasing competition between the two lasing bands. The presence of laser emission at the 680 nm band can lead to quenching or significant reduction of laser emission at the 730 nm band, effectively increasing the lasing threshold for the 730 nm band. Further concentration-dependent studies, along with theoretical analysis, elucidated the mechanism that determines when and why the laser emission band appears at one of the two bands, or concomitantly at both bands. Finally, Chla was exploited as the donor in fluorescence resonance energy transfer to extend the laser emission to the near infrared regime with an unprecedented wavelength shift as large as 380 nm. Our work will open a door to the development of novel biocompatible and biodegradable chlorophyll-based lasers for various applications such as miniaturized tunable coherent light sources and in vitro/in vivo biosensing. It will also provide important insight into the chlorophyll fluorescence and photosynthesis processes inside plants.
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Affiliation(s)
- Yu-Cheng Chen
- Department of Biomedical Engineering, University of Michigan, 1101 Beal Ave., Ann Arbor, MI 48109, USA.
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Chen Q, Kiraz A, Fan X. Optofluidic FRET lasers using aqueous quantum dots as donors. LAB ON A CHIP 2016; 16:353-9. [PMID: 26659274 PMCID: PMC4703430 DOI: 10.1039/c5lc01004g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
An optofluidic FRET (fluorescence resonance energy transfer) laser is formed by putting FRET pairs inside a microcavity acting as a gain medium. This integration of an optofluidic laser and the FRET mechanism provides novel research frontiers, including sensitive biochemical analysis and novel photonic devices, such as on-chip coherent light sources and bio-tunable lasers. Here, we investigated an optofluidic FRET laser using quantum dots (QDs) as FRET donors. We achieved lasing from Cy5 as the acceptor in a QD-Cy5 pair upon excitation at 450 nm, where Cy5 has negligible absorption by itself. The threshold was approximately 14 μJ mm(-2). The demonstrated capability of QDs as donors in the FRET laser greatly improves the versatility of optofluidic laser operation due to the broad and large absorption cross section of the QDs in the blue and UV spectral regions. The excitation efficiency of the acceptor molecules through a FRET channel was also analyzed, showing that the energy transfer rate and the non-radiative Auger recombination rate of QDs play a significant role in FRET laser performance.
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Affiliation(s)
- Qiushu Chen
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Alper Kiraz
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA. and Department of Physics, Koç University, Rumelifeneri Yolu, Sariyer, 34450 Istanbul, Turkey
| | - Xudong Fan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
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Fan X, Yun SH. The potential of optofluidic biolasers. Nat Methods 2014; 11:141-7. [PMID: 24481219 DOI: 10.1038/nmeth.2805] [Citation(s) in RCA: 265] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 11/04/2013] [Indexed: 01/05/2023]
Abstract
Optofluidic biolasers are emerging as a highly sensitive way to measure changes in biological molecules. Biolasers, which incorporate biological material into the gain medium and contain an optical cavity in a fluidic environment, can use the amplification that occurs during laser generation to quantify tiny changes in biological processes in the gain medium. We describe the principle of the optofluidic biolaser, review recent progress and provide our outlooks on potential applications and directions for developing this technology.
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Affiliation(s)
- Xudong Fan
- Biomedical Engineering Department, University of Michigan, Ann Arbor, Michigan, USA
| | - Seok-Hyun Yun
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Cambridge, Massachusetts, USA
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Bog U, Laue T, Grossmann T, Beck T, Wienhold T, Richter B, Hirtz M, Fuchs H, Kalt H, Mappes T. On-chip microlasers for biomolecular detection via highly localized deposition of a multifunctional phospholipid ink. LAB ON A CHIP 2013; 13:2701-7. [PMID: 23649356 DOI: 10.1039/c3lc50149c] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We report on a novel approach to realize on-chip microlasers, by applying highly localized and material-saving surface functionalization of passive photonic whispering gallery mode microresonators. We apply dip-pen nanolithography on a true three-dimensional structure. We coat solely the light-guiding circumference of pre-fabricated poly(methyl methacrylate) resonators with a multifunctional molecular ink. The functionalization is performed in one single fabrication step and simultaneously provides optical gain as well as molecular binding selectivity. This allows for a direct and flexible realization of on-chip microlasers, which can be utilized as biosensors in optofluidic lab-on-a-chip applications. In a proof-of-concept we show how this highly localized molecule deposition suffices for low-threshold lasing in air and water, and demonstrate the capability of the ink-lasers as biosensors in a biotin-streptavidin binding experiment.
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Affiliation(s)
- Uwe Bog
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany.
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Passaro VMN, Troia B, Notte ML, Leonardis FD. Photonic resonant microcavities for chemical and biochemical sensing. RSC Adv 2013. [DOI: 10.1039/c2ra21984k] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Zhang X, Lee W, Fan X. Bio-switchable optofluidic lasers based on DNA Holliday junctions. LAB ON A CHIP 2012; 12:3673-3675. [PMID: 22790530 DOI: 10.1039/c2lc40183e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Bio-switchable optofluidic lasers based on DNA Holliday junctions were demonstrated. Nearly 100% wavelength switching was achieved through reversible conformational change of the Holliday junction controlled by magnesium ionic strength.
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Affiliation(s)
- Xingwang Zhang
- Department of Biomedical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109, USA
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Lee W, Luo Y, Zhu Q, Fan X. Versatile optofluidic ring resonator lasers based on microdroplets. OPTICS EXPRESS 2011; 19:19668-19674. [PMID: 21996908 DOI: 10.1364/oe.19.019668] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We develop a novel nL-sized microdroplet laser based on the capillary optofluidic ring resonator (OFRR). The microdroplet is generated in a microfluidic channel using two immiscible fluids and is subsequently delivered to the capillary OFRR downstream. Despite the presence of the high refractive index (RI) carrier fluid, the lasing emission can still be achieved for the droplet formed by low RI solution. The lasing threshold of 1.54 µJ/mm(2) is achieved, >6 times lower than the state-of-the-art, thanks to the high Q-factor of the OFRR. Furthermore, the lasing emission can be conveniently coupled into an optical fiber. Finally, tuning of the lasing wavelength is achieved via highly efficient fluorescence resonance energy transfer processes by merging two different dye droplets in the microfluidic channel. Versatility combined with improved lasing characteristics makes our OFRR droplet laser an attractive platform for high performance optofluidic lasers and bio/chemical sensing with small sample volumes.
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Affiliation(s)
- Wonsuk Lee
- Department of Biomedical Engineering, University of Michigan, 1101 Beal Ave., Ann Arbor, MI 48109, USA
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Sun Y, Shopova SI, Wu CS, Arnold S, Fan X. Bioinspired optofluidic FRET lasers via DNA scaffolds. Proc Natl Acad Sci U S A 2010; 107:16039-42. [PMID: 20798062 PMCID: PMC2941270 DOI: 10.1073/pnas.1003581107] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Optofluidic dye lasers hold great promise for adaptive photonic devices, compact and wavelength-tunable light sources, and micro total analysis systems. To date, however, nearly all those lasers are directly excited by tuning the pump laser into the gain medium absorption band. Here we demonstrate bioinspired optofluidic dye lasers excited by FRET, in which the donor-acceptor distance, ratio, and spatial configuration can be precisely controlled by DNA scaffolds. The characteristics of the FRET lasers such as spectrum, threshold, and energy conversion efficiency are reported. Through DNA scaffolds, nearly 100% energy transfer can be maintained regardless of the donor and acceptor concentration. As a result, efficient FRET lasing is achieved at an unusually low acceptor concentration of micromolar, over 1,000 times lower than that in conventional optofluidic dye lasers. The lasing threshold is on the order of μJ/mm(2). Various DNA scaffold FRET lasers are demonstrated to illustrate vast possibilities in optofluidic laser designs. Our work opens a door to many researches and applications such as intracavity bio/chemical sensing, biocontrolled photonic devices, and biophysics.
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Affiliation(s)
- Yuze Sun
- Biomedical Engineering Department, University of Michigan, 1101 Beal Avenue, Ann Arbor, MI 48109
- Department of Biological Engineering, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211; and
| | - Siyka I. Shopova
- Department of Biological Engineering, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211; and
- MicroParticle PhotoPhysics Lab, Polytechnic Institute of New York University, Brooklyn, NY 11201
| | - Chung-Shieh Wu
- Department of Biological Engineering, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211; and
| | - Stephen Arnold
- MicroParticle PhotoPhysics Lab, Polytechnic Institute of New York University, Brooklyn, NY 11201
| | - Xudong Fan
- Biomedical Engineering Department, University of Michigan, 1101 Beal Avenue, Ann Arbor, MI 48109
- Department of Biological Engineering, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211; and
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Fan X, White IM, Shopova SI, Zhu H, Suter JD, Sun Y. Sensitive optical biosensors for unlabeled targets: A review. Anal Chim Acta 2008; 620:8-26. [PMID: 18558119 PMCID: PMC10069299 DOI: 10.1016/j.aca.2008.05.022] [Citation(s) in RCA: 794] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2008] [Revised: 05/10/2008] [Accepted: 05/12/2008] [Indexed: 02/07/2023]
Abstract
This article reviews the recent progress in optical biosensors that use the label-free detection protocol, in which biomolecules are unlabeled or unmodified, and are detected in their natural forms. In particular, it will focus on the optical biosensors that utilize the refractive index change as the sensing transduction signal. Various optical label-free biosensing platforms will be introduced, including, but not limited to, surface plasmon resonance, interferometers, waveguides, fiber gratings, ring resonators, and photonic crystals. Emphasis will be given to the description of optical structures and their respective sensing mechanisms. Examples of detecting various types of biomolecules will be presented. Wherever possible, the sensing performance of each optical structure will be evaluated and compared in terms of sensitivity and detection limit.
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