A gold nanorod-based fluorometric immunoassay (nanoELIFA) displayed ∼3.5-fold higher sensitivity (amplified signal) when compared to conventional ELIFA.

Chandra Sekaran N

Centre for Nanobiotechnology

Vellore Campus

Amitava Mukherjee

Alex S.A

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

Gold nanorod-based fluorometric ELISA for the sensitive detection of a cancer biomarker

New Journal of Chemistry

In the current study, we emphasize that osteopontin is overexpressed in oral squamous cell carcinoma. Overexpression of osteopontin levels was confirmed by mRNA quantification studies and immunohistochemistry analysis. Based on this, a gold nanoparticle–based ELISA system was developed for non-invasive osteopontin detection. The incorporation of AuNRs (Gold nanorods) or AuNSs (Gold nanospheres) in the conventional ELISA improved the sensitivity of analyses. A considerably lowered detection limit in case of AuNR (detection limit: 0.02 ng mL− 1) and AuNS (detection limit: 0.03 ng mL− 1) modified assay was obtained as compared to commercially available OPN ELISA kit (detection limit: 0.14 ng mL− 1). The modified ELISA had a wide linear detection range (0.31–20 ng mL− 1), good reproducibility, and specificity against the tested interferents in the saliva. Finally, the nanoELISA was validated with osteopontin spiked in artificial and normal saliva samples and observed to show good recovery (95.4–97.85%), which indicates the application potential of the developed kit for real sample analysis. © 2017 Elsevier B.V.

Clinica Chimica Acta

A facile gold nanoparticle–based ELISA system for detection of osteopontin in saliva: Towards oral cancer diagnostics

Gold nanorods (AuNRs) used for biomedical applications could be encountered by biomolecules in the bloodstream, of which IgG is the most abundant antibody. With a view to mitigate their side effect on encountered proteins, the effect of Au concentration (5–40 μM) and functionalization (CTAB-positive;PSS-negative; PEG-neutral) of AuNRs was investigated on the stability of a model protein, IgG (1 μM). Electron microscopic images and particle size analyses indicated least aggregation behavior for PEG-AuNRs, which can be correlated to their neutral charge (from zeta potential analyses) or stearic hindrance of PEG chains. Variations in tryptophan domain were probed by UV–visible absorption and fluorescence quenching studies. Synchronous fluorescence study helped to provide information regarding variations in the hydrophobic region of IgG. The denaturation studies also indicated the stability of AuNR–IgG complex formation. These studies showed that positively charged IgG (pI: 7.8 ± 1.0) was mostly affected by negatively charged PSS-AuNRs and least affected by PEG-AuNRs. This was verified by secondary structural investigations performed using CD and FTIR spectroscopy. For cytotoxicity studies on human lymphocytes, CTAB-AuNRs are known to show higher toxicity compared to PSS-AuNRs and PEG-AuNRs (least). Though PSS-functionalized AuNRs were shown to affect cells to a lesser degree based on the negative charge of cell membrane, they could hamper with positively charged biomolecules in the bloodstream before they reach the target, which must also be considered for choosing the right AuNR functionalization. Thus, this work indicates the effect of different AuNR functionalization on protein and cellular toxicity and stresses the necessity to use neutral particles to mitigate their side effect for theranostic applications. © 2016 Elsevier B.V.

Materials Science and Engineering: C

Significance of surface functionalization of Gold Nanorods for reduced effect on IgG stability and minimization of cytotoxicity

Talanta

Fluorescence ELISA based on glucose oxidase-mediated fluorescence quenching of quantum dots for highly sensitive detection of Hepatitis B

Journal of Immunological Methods

A copper based enzyme-free fluorescence ELISA for HER2 detection

PLOS ONE

Antibody-nanoparticle conjugates to enhance the sensitivity of ELISA-based detection methods

Journal	Data powered by TypesetNew Journal of Chemistry
Publisher	Data powered by TypesetRoyal Society of Chemistry (RSC)
ISSN	1144-0546
Open Access	0