Curcumin-capped gold nanorods as optical sensing platform for sequence-specific detection of DNA based on their self-assembly

Abstract

We are reporting curcumin-induced gold nanorods as an optical sensing platform for the detection of sequence-specific DNA targets through their self-assembly. The combined effect of eco-friendly reducing agent (i.e., curcumin) and silver nitrate in a basic medium (i.e., pH 10) has been attributed to the formation of small gold nanorods (AuNRs) having approximate length and diameter i.e., 19.7 +/- 0.8 nm and 6.0 +/- 0.5 nm, respectively, and lower longitudinal surface plasmon resonance (SPR) enable to detect and analyze different biomarkers. Further, for evaluating cellular uptake of as-synthesized AuNRs, the cytotoxicity study has been carried out by 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay on A549 cells and HEPG2 cell lines, respectively, and shown approximately similar cytotoxicity. Interestingly, an as-synthesized optically and electronically active AuNRs-based nano biosensing platform enables to detection of sequence-specific DNA targets with a low level of detection limit i.e., LOD 8.6 +/- 0.15 pM for the complementary target (CT) DNA with higher sensitivity and better selectivity. Finally, this study suggests a simplistic bio-mediated approach to tuning the shape and size of AuNRs for sensitive, selective, and reliable nano-biosensing platforms for sequence-specific DNA detection related to cancer cells.