This study demonstrates the effect of size and concentration of the gold nanoparticles (AuNP) labels on the sensitivity of evanescent wave absorbance (EWA) based fiber optic sandwich immunobiosensor. A plasmonic sandwich immunoassay using human Immunoglobulin G (HIgG) and goat anti-HIgG (GaHIgG) was performed on aU-bent polymethyl methacrylate (PMMA) based plastic optical fiber (POF) probe (core diameter \pmb{500\ \mu} \mathbf{m} and bend diameter 1.4 mm). Enhanced EWA response was observed with 60 nm AuNP labels for the analyte concentration \pmb{1\ \mu} \mathbf{g}/\mathbf{ml} in comparison to 20, 40 and 80 nm AuNP labels. Furthermore, on optimizing the GAbs concentration the sensitivity of the sensor enhanced significantly with \pmb{20\times 60} nm labels with a LOD of 100 fg/ml. The advantages such as ease in fiber probe handling and simple instrumentation are highly promising for development of fiberoptic biosensors for various applications. © 2018 IEEE.

Sai V V Raghavendra

Department of Applied Mechanics

M. Divagar

Concentration (process)

Fiber optic sensors

Fiber optics

Gold Nanoparticles

immunology

Metal nanoparticles

NANOMETALS

Optical fibers

PLASMONIC NANOPARTICLES

Plasmonics

Plasmons

Polymethyl methacrylates

Probes

Silicon compounds

Analyte concentration

EFFECT OF SIZES

Evanescent wave

Human immunoglobulin g

IMMUNOBIOSENSOR

PLASTIC OPTICAL FIBER (POF)

SANDWICH IMMUNOASSAY

size

PLASTIC OPTICAL FIBERS

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Fiber Optic Plasmonic Sandwich Immunosensor: Influence of AuNP Label Size and Concentration

Proceedings of IEEE Sensors

This study demonstrates a simple evanescent wave absorbance based sensing scheme for plasmonic sandwich immunoassay with the help of U-bent fiber probes as transducers. High absorbance sensitivity of the U-bent probes (200 μm core and 1.5 mm bend diameter) is exploited for sensitive detection of a small number of gold nanoparticles (AuNP) labels bound to the probe for the first time. Using 13 nm AuNP labels conjugated with recognition antibodies, picomolar detection limit (2 pM or 0.3 ng/ml) for human immunoglobulin (HIgG) is achieved. The absorbance sensitivity and dynamic range were 0.019 A530nm/log (ng/ml) and 1-105 ng/ml respectively. Nonspecific adsorption (NSA) of labels is minimized to less than 2% by PEGylation. The ease in U-bent probe fabrication and simple optoelectronic instrumentation consisting of an LED and a fiber optic spectrometer could facilitate extensive use of U-bent probes for several biosensing applications. © 2015 Elsevier B.V. All rights reserved.

Sensors and Actuators, B: Chemical

Evanescent wave absorbance based U-bent fiber probe for immunobiosensor with gold nanoparticle labels

This study presents design and development of evanescent wave absorbance based U-bent plastic optical fiber (POF) probe with high sensitivity and its applications to refractive index (RI) sensing. The probes were fabricated by a controlled decladding procedure to remove the fluorinated polymer without damaging the poly methyl methacrylate (PMMA) core and a simple and scalable fabrication technique to obtain POF U-bent probes of desired geometry. U-bent probes of fiber diameter from 250 to 1000 μm were fabricated and optimum bend diameter for each fiber diameter was investigated. The sensitivity was found to be maximum when the bend diameter of the probe varies from 2 to 3 times the fiber diameter. Probes with 500 μm core and 1.25 mm bend diameter showed highest sensitivity (5.57ΔA560 nm/ΔRIU) in the visible region to RI changes from 1.33 to 1.47 with a resolution better than 1 milli RI units. Furthermore, U-bent probes were amine functionalized and coated with gold nanoparticles to obtain a localized surface plasmon resonance (LSPR) based RI sensor that has an 8-fold improvement in RI sensitivity, hence extending their applicability to plasmonic biosensing. © 2016 Elsevier B.V. All rights reserved.

Development of LSPR based U-bent plastic optical fiber sensors

Sensors

Development of Lateral Flow Assay Based on Size-Controlled Gold Nanoparticles for Detection of Hepatitis B Surface Antigen

Analytical Chemistry

Fiber-Optic Chemical Sensors and Biosensors (2013–2015)

Enhancing Sensitivity of Surface Plasmon Resonance Biosensors by Functionalized Gold Nanoparticles: Size Matters

Journal	Data powered by TypesetProceedings of IEEE Sensors
Publisher	Data powered by TypesetInstitute of Electrical and Electronics Engineers Inc.
ISSN	19300395
Open Access	No