Work

AgNPs-based Label-Free Colloidal SERS Nanosensor for the Rapid and Sensitive Detection of Stress-Proteins Expressed in Response to Environmental-Toxins

Year: 2013

Type: article

Abstract: Among several physical, chemical and immunoassay-based methods for the detection of biomolecules, the Enzyme-Linked Immuno-Sorbent Assay (ELISA) is the standard technique that is routinely used for quantification of known proteins.However, it is a label-based, end-point sensor technique that is time-consuming, labor-intensive and fairly costly.This sandwich assay typically involves a series of peptide binding and washing steps.Here, we report a Surface-Enhanced Raman Spectroscopy (SERS) immuno-nanosensor technique that allows rapid and label-free extracellular detection of proteins compared to ELISA, and can potentially be used for intracellular detection.Our study shows that the silver nanoparticles (AgNPs) based SERS sensor can detect the stress-proteins, HSP70 and RAD54 expressed by yeast in response to environmental-toxins, in a dose dependent manner.As compared to the multi-step sandwich ELISA technique, the detection of stress-proteins using the SERS sensor is a simple two-step process.The simplicity of the SERS nanosensor design allowed the rapid detection of proteins within two hours in a fairly cost-effective and user-friendly approach.The SERS sensor we reported has an edge over ELISA as it directly quantifies the proteins without using any label (label-free) and also gives qualitative information about the antigen-antibody interaction.The SERS sensor showed good correlation and comparable sensitivity with ELISA.However, SERS was found to be less reproducible.Compared to previous reports on SERS-based protein detection techniques, our colloidal SERS sensor is easy to fabricate, offers improved biocompatibility, and allows rapid detection of the proteins in a cellular environment at picogram-levels.As a result, the SERS sensor demonstrates great potential for biomedical and environmental sensor technology (BEST) allowing label-free, rapid and sensitive detection, and could possibly replace ELISA.

Source: Journal of Biosensors & Bioelectronics

DOI: 10.4172/2155-6210.s12-005

Authors: Vinay Bhardwaj, Supriya Srinivasan, Anthony J McGoron

Institution: Florida International University

Language: English

Topic: Gold and Silver Nanoparticles Synthesis and Applications

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: hybrid

Funders: U.S. Department of Defense, Florida International University