Gold Nanorod, an Optical Probe to Track HIV Infection

Santosh Kumar

doi:10.4236/jst.2012.21006

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.

Highlights

Infectious diseases remain the leading killers of human civilization worldwide, and function to destabilize societies in Africa, Asia and the Middle East
Driven by the need to detect the presence of human immunodeficiency virus (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
In this article, we demonstrate the second order nonlinear optical (NLO) properties [21,22,23,24,25,26,27] of gold nanomaterial can be used for screening HIV DNA without any modification, with excellent sensitivity (100 pico-molar) and selectivity

Summary

Introduction

Infectious diseases remain the leading killers of human civilization worldwide, and function to destabilize societies in Africa, Asia and the Middle East. Nano-surface fluorescence energy transfer (NSET) [13,14,15,16] and Surface enhanced Raman spectroscopic technique (SERS) [17,18,19,20] have been shown to be highly promising technologies to detect DNA present at very low concentrations. These assays identify specific sequence through hybridization of an immobilized probe to the target analyte after the latter has been modified with a covalently linked label such as a fluorescent or Raman tag. Sensitive, and tunable optical scattering properties, here we have shown that the hyper-Rayleigh scattering (HRS) technique [6,21,22,23,24,25,26,27] which has emerged over the past decade as a powerful method to determine the microscopic non-linear optical (NLO) properties of species in solution, can be used to achieve detection of HIV-DNA with excellent sensitivity (100 pM) and selectivity

Synthesis and Characterization of Gold Nanorods

Preparation of DNA Gold Nanorod Conjugates

Hyper Rayleigh Scattering Spectrosocpy

NLO Properties of Gold Nanorods and Evidence for Multipoles

Sequence Specific HIV-1 Gag Gene DNA Diaginistics

Conclusions