GaAs/AlGaAs heterostructure based photonic biosensor for rapid detection of Escherichia coli in phosphate buffered saline solution

Nazemi, Elnaz; Aithal, Srivatsa; Hassen, Walid; Frost, Éric; Dubowski, Jan J.

doi:10.1016/j.snb.2014.10.111

Cited by 50 publications

(53 citation statements)

References 65 publications

(71 reference statements)

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“…GaAs nanostructures are becoming more widespread in many applications including optoelectronic devices [1], solar cells [2], light-emitting diodes (LEDs) [3], tunnel field-effect transistors (TFETs) [4], thermoelectric devices [5], and biosensing [6]. Top-down and bottom-up methods are two approaches used to produce GaAs nanostructures by a variety of physical [7, 8], chemical [9], and electrochemical etching techniques [10].…”

Section: Introductionmentioning

confidence: 99%

Chemical Composition of Nanoporous Layer Formed by Electrochemical Etching of p-Type GaAs

et al. 2016

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We have performed a detailed characterization study of electrochemically etched p-type GaAs in a hydrofluoric acid-based electrolyte. The samples were investigated and characterized through cathodoluminescence (CL), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). It was found that after electrochemical etching, the porous layer showed a major decrease in the CL intensity and a change in chemical composition and in the crystalline phase. Contrary to previous reports on p-GaAs porosification, which stated that the formed layer is composed of porous GaAs, we report evidence that the porous layer is in fact mainly constituted of porous As2O3. Finally, a qualitative model is proposed to explain the porous As2O3 layer formation on p-GaAs substrate.

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Section: Introductionmentioning

confidence: 99%

Chemical Composition of Nanoporous Layer Formed by Electrochemical Etching of p-Type GaAs

et al. 2016

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“…[3][4][5] Gallium arsenide (GaAs) is a popular photonic material found in fabrication of semiconductor lasers and light emitting devices. We have recently demonstrated rapid detection of Escherichia coli at 10 3 CFU/ml, 6,7 and Legionella pneumophila at 10 4 CFU/ml, 8 using photoluminescence (PL) emitting GaAs/AlGaAs microstructures. The detection sensitivity of such photonic biosensors depends on the efficiency of bacteria immobilization on their surfaces.…”

Section: Introductionmentioning

confidence: 99%

Chemotaxis for enhanced immobilization of Escherichia coli and Legionella pneumophila on biofunctionalized surfaces of GaAs

et al. 2016

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The authors have investigated the effect of chemotaxis on immobilization of bacteria on the surface of biofunctionalized GaAs (001) samples. Escherichia coli K12 bacteria were employed to provide a proof-of-concept of chemotaxis-enhanced bacterial immobilization, and then, these results were confirmed using Legionella pneumophila. The recognition layer was based on a self-assembled monolayer of thiol functionalized with specific antibodies directed toward E. coli or L. pneumophila, together with the enzyme beta-galactosidase (β-gal). The authors hypothesized that this enzyme together with its substrate lactose would produce a gradient of glucose which would attract bacteria toward the biochip surface. The chemotaxis effect was monitored by comparing the number of bacteria bound to the biochip surface with and without attractant. The authors have observed that β-gal plus lactose enhanced the immobilization of bacteria on our biochips with a higher effect at low bacterial concentrations. At 100 and 10 bacteria/ml, respectively, for E. coli and L. pneumophila, the authors observed up to 11 and 8 times more bacteria bound to biochip surfaces assisted with the chemotaxis effect in comparison to biochips without chemotaxis. At 10(4) bacteria/ml, the immobilization enhancement rate did not exceed two times.

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“…Self‐assembly of thiolated alkanes onto gold surfaces has been investigated using different methods, including XPS and 32 P‐radiolabeling 27, neutron reflectivity 28, surface plasmon resonance 29–31, quartz crystal microbalance 32, 33 and electrochemical methods 34–37. In the present study formation of SAM onto gold electrode, activation of hydroxyl groups by the new method and immobilization of anti‐CAL onto modified electrode were characterized by using cyclic voltammetry and electrochemical impedance spectroscopy.…”

Section: Resultsmentioning

confidence: 98%

Quantitative Analysis of a Promising Cancer Biomarker, Calretinin, by a Biosensing System Based on Simple and Effective Immobilization Process

2015

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Calretinin (CAL) is calcium binding protein, and its levels in blood and cerebrospinal fluids are increased, since its expression is increased various cancer types. A novel biosensor system fabricated by immobilization of a specific antibody to CAL, anti‐Calretinin (anti‐CAL), onto a gold electrode surface via an effective covalent binding method using mercaptohexanol, epichlorohydrin, and ethanolamine was reported for the sensitive, selective, and accurate analysis of CAL. The proposed biosensor showed a linear calibration range between 1 ng/mL and 5 ng/mL. LOD and LOQ values were determined as 0.11 ng/mL and 0.38 ng/mL, respectively. The standard deviation related to the reproducibility of the new biosensor system was calculated as 3.95 %. Lastly, in order to state the applicability of the biosensor to early diagnosis of CAL in practice, artificial serum samples spiked with CAL have been analyzed by the proposed biosensor.

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GaAs/AlGaAs heterostructure based photonic biosensor for rapid detection of Escherichia coli in phosphate buffered saline solution

Cited by 50 publications

References 65 publications

Chemical Composition of Nanoporous Layer Formed by Electrochemical Etching of p-Type GaAs

Chemical Composition of Nanoporous Layer Formed by Electrochemical Etching of p-Type GaAs

Chemotaxis for enhanced immobilization of Escherichia coli and Legionella pneumophila on biofunctionalized surfaces of GaAs

Quantitative Analysis of a Promising Cancer Biomarker, Calretinin, by a Biosensing System Based on Simple and Effective Immobilization Process

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