A Highly Sensitive Colorimetric Method for Copper Ions Detection Based on Controlling the Peroxidase-like Activity of Au@Pt Nanocatalysts

Abstract

In this study, a sensitive colorimetric method for the detection of copper ion (Cu 2+ ) was developed based on controlling the peroxidase-like activity of (gold core)@(ultrathin platinum shell) nanocatalysts (Au@Pt-NCs). It was found that D-penicillamine can effectively inhibit the activity of Au@Pt-NCs. After being incubated with Cu 2+ , D-penicillamine lost inhibition toward the catalytic ability of Au@Pt-NCs. Based on the above interaction, a colorimetric detection of Cu 2+ was develop by measuring the colorimetric signal variation of the H2O2-3,3′,5,5′-tetramethylbenzidine (TMB) reaction. This method exhibited high sensitivity and selectivity toward Cu 2+ over a panel of other metal ions. The detection limit of this method was 3.7 nM and the linear range was 20 -300 nM. Moreover, 20 nM Cu 2+ can be distinguished directly by the naked eye. Furthermore, this method was applied to the analysis of water samples with good accuracy. These results demonstrated the excellent application potential of the method.

Enzyme-free Gold-silver Core-shell Nanozyme Immunosensor for the Detection of Haptoglobin

“…21,22 Furthermore, the ability of AuNPs to provide stable immobilization of biomolecules whilst retaining their bioactivity is highly advantageous in the preparation of biosensors. 23 These aforementioned properties of AuNPs have seen them being used as a seed or core in the synthesis of core-shell nanoparticle structure, [24][25][26][27] and as a template for nanoparticle growth. [28][29][30] Gold seeding enables the growth of the nanoparticle shell to be tuned to the shape of the gold seed itself, thus allowing the shape, size and thickness of the nanoparticle to be controlled during synthesis.…”

Umbelliferone as a Small Molecular Peroxidase Mimic towards Sensitive Detection of H2O2 and Glucose

“…Hence, increasing attention has been paid by researchers to discovering and constructing enzyme mimics with similar functions to that of natural enzymes. 5 Since Yan's group reported on the intrinsic peroxidase-like activity of ferromagnetic nanoparticles in 2007, 6 a series of nanomaterial-based artificial enzymes, including metal nanoparticles, [7][8][9] metal oxides and their combined nanostructures, [10][11][12] and carbon-based materials, 13 have also been affirmed to have peroxidase-like activities during the past few decades. They occupied excellent superiorities over traditional natural enzymes, such as easy preparation and storage, design flexibility and good stability under diversified conditions.…”

A Simple Colorimetric Method to Quantify Total Fecal Oil Using Oil-soluble Dyes in Laboratory Animals and Its Correlation with Liquid Chromatography-Mass Spectrometry Analysis

“…We performed experiments using eight oil-soluble dyes that are routinely used to stain fat in feces in order to examine the correlation between the amount of excreted oil and dye. [9][10][11][12] This paper introduces our new simple method, a colorimetric assay, 13,14 which enables the accurate quantification of oil in the excrement of laboratory animals.…”