Gold-nanoparticle-based miniaturized laser-induced fluorescence probe for specific DNA hybridization detection: studies on size-dependent optical properties

Abstract

A compact, highly specific, inexpensive and user friendly optical fibre laser-induced fluorescence (LIF) sensor based on fluorescence quenching by nanoparticles has been developed to detect single-strand (ss-) DNA hybridization at femtomolar level. The fluorescence of fluorophore-tagged ss-DNA increases by a factor of 80 when it binds to a complimentary DNA, while the addition of single-base mismatch DNA had no effect on the fluorescence efficiency. We present theoretical and experimental results on dye fluorescence quenching induced by gold nanoparticles having different particle sizes. Fluorescence spectra clearly show that the quenching efficiency decreases with increasing size of the gold nanoparticles and increasing the distance between dye and nanoparticles. The mechanism of size- and distant-dependent fluorescence quenching has been discussed. Effects of various influential experimental parameters and configurations were investigated in order to optimize and miniaturize the sensor performance.

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

“…Transmission electron microscope (TEM) and UV-visible absorption spectrum were used to characterize the nanoparticles. The particle concentration was measured by UV-visible spectroscopy using the molar extinction coefficients at the wavelength of the maximum absorption of each gold colloid as reported recently 11,[25][26][27][28] [ (15) …”

Biosynthesis of gold nanoparticles using chloroplasts

“…[1][2][3][4] Among various MNPs, gold nanoparticles (GNPs) have been extensively studied based on their unique optoelectronic and electrochemical properties. The unique properties of GNPs have been potentially of interest for biological applications including sensors, 5,6 catalysts, 7 optical probes, [8][9][10] tumor photothermal therapy, 11 biomedical engineering, 12 and surface-enhanced Raman scattering (SERS). [13][14][15] Today, biosynthesis of GNPs using plants or plant extracts, 16,17 fungus, [18][19][20] and bacteria, 21,22 has been actively exploited.…”

Enzymatic Formation of Gold Nanoparticles Using <i>Phanerochaete Chrysosporium</i>

“…Synthesis of metal nanoparticles of various size and shape and their colloidal stabilization through biomolecule immobilization is very essential due to their usefulness in many applications such as sensors [1], catalysis [2], chemical [3], optoelectronics [4], single-electron transistors, light emitters [5], and in vivo imaging [6]. The wide range of applications shown by nanomaterials is mainly due to their large surface area and small size.…”