Gold‐Nanorod‐Based Sensing of Sequence Specific HIV‐1 Virus DNA by Using Hyper‐Rayleigh Scattering Spectroscopy

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 45 times when a 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.

Selective Detection of Mercury (II) Ion Using Nonlinear Optical Properties of Gold Nanoparticles

“…However, when the particle size approaches the wavelength, the dipolar picture may no longer provide a complete description, and higher multipolar interactions should be considered, as we discussed before. 20 Since there is a center of inversion in nanoparticle, the HRS intensity arising from a gold nanoparticle cannot be due to electric-dipole contribution. At the microscopic scale, the breaking of the centrosymmetry is required for the harmonic generation process at the surface of the particle.…”

“…This contribution is very important when the size of the particle is no longer negligible when compared to the wavelength, as we reported before. 20,[24][25][26] Figure 2 shows how the HRS intensity varies after addition of different concentrations of Hg (II) into modified gold nanoparticle solution (12 nM). We observed a very distinct HRS intensity change (about 1.2 times) even after addition of 5 ppb Hg(II) as shown in Figure 2b.…”

Application of nanodiagnostics in point-of-care tests for infectious diseases

“…For instance, the gold nanorods have been used to diagnose HIV through their second-order nonlinear optical properties. 46 A 100 picomolar target DNA can be recognized by a 145-mer oligonucleotide probe, which was recorded by a hyperRayleigh scattering (HRS) spectroscopy with high sensitivity and selectivity. The gold nanorods have demonstrated a rapid, simple, and efficient detection of single-base-mismatch HIV-1 virus DNA through the HRS intensity changes.…”

Application of Dynamic Light Scattering and Absorption Spectroscopy to Studies of Systems with Colloidal Gold Nanoparticles + DNA

“…Как показано на рис. 6, нормализованное стандартное отклонение составляет около 0.06 и основанный на ДРС нижний предел обнаружения составляет около 10 пМ оцДНК, что существенно меньше предела чувствительности спектроскопии экс-тинкции, полученного ранее в работах [44,45]. Следует, однако, отметить, что имеется от-личие более чем на два-три порядка в пределах чувствительности детекции оцДНК, согласно нашим данным и данным работы [44] (10− 100 пM), с одной стороны, и по данным работы [46] (0.1 пM), с другой.…”