Highly Sensitive Visual Detection of Copper Ions Based on the Shape-Dependent LSPR Spectroscopy of Gold Nanorods

Abstract

ABSTRACT:We have developed a novel approach to the rapid visual detection of Cu 2+ in natural samples based on the copper-mediated leaching of gold nanorods (GNRs). In the presence of hexadecyltrimethylammonium bromide, which can reduce the redox potential of Au(I)/ Au, the GNRs are catalytically etched by Cu 2+ preferentially along the longitudinal direction. And as a result, the localized surface plasmon resonance extinction peak shifts to short wavelength, accompanied by a color change from blue to red. The leaching mechanism has been carefully discussed in a series of control experiments. Under optimal conditions, this sensor exhibits good sensitivity (LOD = 0.5 nM). Most importantly, the approach is highlighted by its high selectivity for and tolerance of interference, which enables the sensor to detect Cu 2+ directly in a complex matrix, especially in seawater. Moreover, such a nanoparticle-based sensor is also successfully applied to test paper for the visual detection of Cu 2+ .

Iodine-Mediated Etching of Gold Nanorods for Plasmonic ELISA Based on Colorimetric Detection of Alkaline Phosphatase

“…These results are consistent with our previous reports. 11,17 Experimental results also indicate that CTA + and I − (halide ions) have synergy effects on the etching of gold nanoparticles ( Figure S1B). …”

A highly sensitive colorimetric metalloimmunoassay based on copper-mediated etching of gold nanorods

“…[37][38][39][40] In this work, we combine the conventional metalloimmunoassay with copper-mediated etching of gold nanoparticles proposed in our previous work to develop an effective immunoassay using a microplate reader or a spectrophotometer as readout. The experiment results show that this immunoassay is more sensitive than the traditional ELISA and HRP mimic nanomaterial tag-based immunoassay.…”

Highly sensitive on-site detection of glucose in human urine with naked eye based on enzymatic-like reaction mediated etching of gold nanorods

“…Gold nanorods (GNRs) have gained increasing attention in fabrication of nonaggregation-based colorimetric sensors (Liu et al, 2013;Saa et al, 2014;Zhang et al, 2015aZhang et al, , 2014aZhang et al, , 2014bZhang et al, , 2015b) based on shapedependent LSPR property (Pérez-Juste et al, 2005). In contrast to aggregation-based sensors, this kind of sensors possesses obvious advantages: (1) they are label-free, avoiding the modification of nanoparticles; (2) they don't face the false positive signal from autoaggregation; (3) they can be made into test paper; (Zhang et al, 2014b) and (4) GNRs have tunable plasmonic bands and high stability. Most recently, some researchers have successfully applied GNRs for glucose sensing (Liu et al, 2013;Saa et al, 2014).…”