Hollow bimetallic nanostructures have recently emerged as attractive plasmonic materials due to the ease of optical tunability by changing their size/composition.

Jitendra Satija

Centre for Nanobiotechnology

Vellore Campus

J. Satija

Joseph Tharion

Soumyo Mukherji

Tharion J

Mukherji S.

Fiber optics

Fibers

Gold

Nanospheres

Nanostructures

Plasmons

Polydispersity

Probes

Refractive index

Silver

Substitution reactions

Surface plasmon resonance

Bimetallic nanostructures

Fiber optic biosensor

Galvanic replacement reactions

Gold nanostructures

Human immunoglobulin g

Localized surface plasmon resonance

optical tunability

refractive index sensitivity

Fiber optic sensors

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

RSC Advances

Journal of Nanoscience and Nanotechnology

Bimetallic Hollow Nanostructures for Colorimetric Detection of Picomolar Level of Mercury

Various strategies (single &amp; multi-pot) to synthesize dendrimer-coated metal nanoparticles and their exploration in various biomedical applications.

Journal of Materials Chemistry B

Dendrimer as a multifunctional capping agent for metal nanoparticles for use in bioimaging, drug delivery and sensor applications

Convergence of localized surface plasmon resonance of metal nanoparticles with classical ELISA has emerged as a new class of immunoassays, i.e. plasmonic ELISA, enabling biocatalysis mediated ultrasensitive naked-eye detection of disease biomarkers.

Plasmonic-ELISA: Expanding horizons

α-Synuclein protein, whose aggregation is associated with Parkinson's disease, is detected using a compact, label-free, localized surface plasmon resonance (LSPR) based optical sensor. U-shaped fiber optic probe immobilized with gold nanoparticles (GNP), and subsequently functionalized using a film of chitosan was used as a sensing platform. The chitosan film acts as a sensitive and selective polysaccharide bioreceptor for detection of α-Synuclein. Binding of amyloid proteins to this film causes a localized change of dielectric constant surrounding the nanoparticles, leading to a change in the spectrum at the output end of the fiber. The combination of binding rate kinetics and intensity change was measured to develop a robust sensing platform. The sensor could detect the presence of monomers & amyloid fibrils independently up to 70 nM and could differentiate them in mixtures having fibril to monomer ratio from 0.1 to 10, within 15 min. The present study introduces a new platform for sensitive detection of amyloid fibrils and monomer of α-Synuclein (independently as well as in mixtures) for potential applications in inhibition and aggregation based studies. © 2017 Elsevier B.V.

Sensors and Actuators, B: Chemical

Detection and differentiation of Α-Synuclein monomer and fibril by chitosan film coated nanogold array on optical sensor platform

Hollow gold nanostructures (HGNS) have been used in variety of optical biosensors due to their inherent advantage of operating at near infra red (NIR) wavelength, large extinction coefficient and high dielectric sensitivity. The absorption wavelength of these nanostructures can be modulated by changing the ratio of hollow region to the core shell thickness. The aim of the present study is to incorporate the properties of HGNS, to develop LSPR based U-bent fiber optic sensor for detection of pathogens. The detection was carried out using an experimental set up consisting of a white light source, 200 μm diameter optical fiber having bend diameter of 1.6 mm ± 0. 2 mm and a spectrometer. The HGNS were immobilized on the decladded portion of the fiber optic probe by chemisorptions. The effective plasmon penetration depth of the HGNS immobilized fiber optic sensor was approximated by using alternating layers of positively and negatively charged polyelectrolytes. The HGNS immobilized U-bent fiber optic sensor was used for detection of E.coli B40 strain using bacteriophage T4. The preliminary experiments were carried out with 104 cfu/ml of E.coli B40 and the change in absorbance obtained was approx. 0.042 ± 0.0045 abs. units (n = 3). The response of this sensor was found to be better than spherical gold nanoparticle immobilized sensing platforms. © 2016 SPIE.

Proceedings of SPIE - The International Society for Optical Engineering

Detection of bacteria using bacteriophage with hollow gold nanostructures immobilized fiber optic sensor

The refractive index (RI) sensitivity of a localized surface plasmon resonance (LSPR)-based fiber-optic probes is dependent on surface coverage of gold nanoparticles (GNP), fiber core diameter, and probe geometry. For U-bent LSPR fiber-optic probes, which demonstrated an order higher absorption sensitivity over straight probes, bend diameter and probe length may also have a significant influence on the sensitivity. This study on U-bent fiber-optic LSPR probes is aimed at optimizing these parameters to obtain highest possible RI sensitivity. RI sensitivity increases linearly as a function of surface coverage of GNP in the range of 2–22%. U-bent fiber-optic probes made of 200-, 400-, and 600-μm fiber core diameter show optimum bend diameter value as ∼1.4 mm. In addition, RI sensitivity is almost the same irrespective of fiber core diameter demonstrating flexibility in choice of the fiber and ease in optical coupling. The length of the probe preceding and succeeding the bend region has significantly less influence on RI sensitivity allowing miniaturization of these probes. In addition to these experimental studies, we present a theoretical analysis to understand the relative contribution of evanescent wave absorbance of GNP and refractive losses in the fiber due to GNP, towards the RI sensitivity. © Springer Science+Business Media New York 2013.

Plasmonics

Optimal design for U-bent fiber-optic LSPR sensor probes

Localized Surface Plasmon Resonance-Based Fiber Optic U-Shaped Biosensor for the Detection of Blood Glucose

Small

Highly Size- and Shape-Controlled Synthesis of Silver Nanoparticles via a Templated Tollens Reaction

ACS Applied Materials & Interfaces

Ultrasmall Hollow Gold–Silver Nanoshells with Extinctions Strongly Red-Shifted to the Near-Infrared

Chemical Reviews

Localized Surface Plasmon Resonance Sensors

Facile synthesis of size and wavelength tunable hollow gold nanostructures for the development of a LSPR based label-free fiber-optic biosensor

Journal	Data powered by TypesetRSC Advances
Publisher	Data powered by TypesetRoyal Society of Chemistry
ISSN	20462069
Open Access	No