Gold Nanorod, an Optical Probe to Track HIV Infection

Abstract

Infectious diseases caused by the human immunodeficiency virus (HIV) remain the leading killers of human beings worldwide, and function to destabilize societies in Africa, Asia and the Middle East. Driven by the need to detect the presence of HIV viral sequence, here we demonstrate that the second order nonlinear optical (NLO) properties of gold nanorods can be used for screening HIV-1 viral DNA sequence without any modification, with good sensitivity (100 pico-molar) and selectivity (single base pair mismatch). The hyper Rayleigh Scattering (HRS) intensity increases 58 times when label-free 145-mer, ss-gag gene DNA, was hybridized with 100 pM target DNA. The mechanism of HRS intensity change has been discussed with experimental evidence for higher multipolar contribution to the NLO response of gold nanorods