Optical Biosensors

Borisov, Sergey M.; Wolfbeis, Otto S.

doi:10.1021/cr068105t

Cited by 956 publications

(591 citation statements)

References 405 publications

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“…To address this need, sensor technologies with a wide-range of detection modalities, including optical, mechanical, magnetic, and electrochemical, have been devised 3,4 . The detection systems commonly need to be fast, accurate, and sensitive.…”

Section: Introductionmentioning

confidence: 99%

Effect of Nanoporous Gold Thin Film Morphology on Electrochemical DNA Sensing

2015

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Advances in materials science and chemistry have led to the development of a wide range of nanostructured materials for building novel electrochemical biosensors. A systematic understanding of the challenges related to electrode morphology involved in designing such sensors is essential for developing effective biosensing tools. In this study, we use nanoporous gold (npAu) thin film electrode coatings with sub-micron thicknesses, as a model system to investigate the influence of nanostructuring on DNA-methylene blue (MB) interactions and their application for DNA biosensors. The interaction of single-and double-stranded DNA immobilized onto morphologically different np-Au films with MB was electrochemically interrogated via square wave voltammetry (SWV). The electrochemical signal from these electrodes in response to MB decayed progressively with each SWV scan. The decay rate was governed by accessibility of the electrochemically-active np-Au surface by the analyte. The optimum frequency for extracting the maximum signal via SWV was influenced by the film morphology, where the optimum frequency was lower for the nanoporous morphology with lower density of molecular access points into the porous coating. Overall, the np-Au electrodes exhibited a 10-fold enhancement in probe grafting density and approximately 10-fold higher electrochemical current upon probetarget hybridization as compared to the planar Au electrodes. The np-Au electrodes enabled sensitive detection with a dynamic range of 10 nM to 100 nM that shifts by an order of magnitude for coarsened np-Au morphology due to increased target penetration into the porous network and hence enhanced hybridization efficiency. These findings provide insight into the influence of nanostructuring on the transport mechanisms of small molecules and nucleic acids, and yield an understanding of diverse sensor performance parameters such as DNA grafting density, hybridization efficiency, sensitivity and dynamic range.

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Section: Introductionmentioning

confidence: 99%

Effect of Nanoporous Gold Thin Film Morphology on Electrochemical DNA Sensing

2015

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“…It is defined as a group of metabolic diseases where ultimately the body's pancreas does not produce enough insulin or does not properly respond to insulin produced, resulting in high blood sugar levels over a prolonged period. Glucose meters and other POC devices utilize an assortment of methods for detecting and monitoring biomarkers including electrochemical [16][17][18][19][20], magnetic [21][22][23][24][25][26][27][28][29][30], optical [31][32][33][34], label-free spectroscopic analysis [35][36][37][38][39][40][41][42][43], colorimetric [44][45][46][47][48][49], and plasmonic nanoparticle based sensors [50][51][52]. Generally, electrochemical detection uses potentiometric, amperometric, and impedimetric measurements in conjunction with electroactive tags or free flowing electroactive analytes [17][18][19][20] [15,53,54] are examples of electrochemical and colorimet...…”

Section: Current Commercial Poc Technologiesmentioning

confidence: 99%

“…In many cases, optical approaches are more successful in simultaneously sensing multiple analytes through the use of photoactive dyes conjugated to biorecognition ligands [33]. Indirect sensing through the identification of optically active molecules, including chromophores and fluorophores or other reporter molecules, has improved the sensitivity and multiplexing capabilities of techniques like Raman or fluorescence spectroscopy while simultaneously lowering the limits of detection (LODs) and broadening the dynamic range of spectroscopic analysis [31,90].…”

Section: Optical Analyses For Facilitating Poc Technologiesmentioning

confidence: 99%

Surface enhanced Raman spectroscopy (SERS) for in vitro diagnostic testing at the point of care

et al. 2017

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Point-of-care (POC) device development is a growing field that aims to develop low-cost, rapid, sensitive in-vitro diagnostic testing platforms that are portable, selfcontained, and can be used anywhere -from modern clinics to remote and low resource areas. In this review, surface enhanced Raman spectroscopy (SERS) is discussed as a solution to facilitating the translation of bioanalytical sensing to the POC. The potential for SERS to meet the widely accepted "ASSURED" (Affordable, Sensitive, Specific, Userfriendly, Rapid, Equipment-free, and Deliverable) criterion provided by the World Health Organization is discussed based on recent advances in SERS in vitro assay development. As SERS provides attractive characteristics for multiplexed sensing at low concentration limits with a high degree of specificity, it holds great promise for enhancing current efforts in rapid diagnostic testing. In outlining the progression of SERS techniques over the past years combined with recent developments in smart nanomaterials, high-throughput microfluidics, and low-cost paper diagnostics, an extensive number of new possibilities show potential for translating SERS biosensors to the POC.

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“…The optical signals are collected by a photodector and converted into electrical signals that are further electronically processed. There are many reviews on optical biosensors, the one by Borisov & Wolfbeis, 2008, is highly recommended. The main optical phenomena employed in optical immunosensors are summarized in Table 1.…”

Section: Optical Immunosensorsmentioning

confidence: 99%