Journal of Nanomedicine & Nanotechnology

Abstract

Assembly of a Dual Aptamer Gold Nanoparticle Conjugate Ensemble in the Specific Detection of Thrombin when Coupled with Dynamic Light Scattering Spectroscopy

Vishala S Ramyah Aaryasomayajula, Tiffany Severs, Kartik Ghosh, Robert DeLong, Xianfeng Zhang, Saikat Talapatra and Adam K Wanekaya

We demonstrate an extremely facile, rapid, specific and selective method for detecting proteins using aptamerconjugated gold nanoparticles coupled with dynamic light scattering (DLS) at ambient conditions. Addition of proteins to aptamer-conjugated gold nanoparticles (GNPs) induced the formation of protein-aptamer-gold nanoparticle conjugate complexes. The average hydrodynamic diameter of the nanoconjugate complexes as measured by DLS, increased with the corresponding increase in protein concentration. This correlation formed the analytical basis of the assay. The nanoparticles and nanoconjugate complexes were characterized by transmission electron microscopy, ultra-violet visible spectroscopy and DLS. Various parameters affecting the assay were optimized. Using thrombin as the model analyte, we demonstrated the detection of as low as 1.41 nM (0.05 μg/mL) of the protein. A linear dynamic range of up to 300 nM (11 μg/mL) was realized. The presence of other interfering proteins such as BSA showed no effect on the assay response.The presence of other interfering proteins such as bovine serum albumin (BSA) showed no significant effect on the assay response.