Fluorescent Ag Nanoprobes for the Highly Selective Detection of Mercury (II) Ions and Colorimetric Detection of Hydrogen Peroxide

Abstract

In this article, we report on the easy synthesis of fluorescent Ag nanoclusters (Ag NCs) and demonstrate their multifunctional use in highly selective sensing Hg 2+ and colorimetric detection of H 2 O 2 and glucose. The red emission fluorescent Ag NCs were prepared using polymethacrylic acid sodium salt (PMAA) and polyvinylpyrrolidone (PVP) as templates via a convenient hydrothermal process. The Ag NCs were then used in the sensitive and selective detection of Hg 2+ based on the fluorescence quenching behavior. The detection limit was 10 nM in the linear range from 10 nM to 16 M. We further demonstrate the novel use of the as-prepared Ag NCs as a dual channel probe for colorimetric and fluorescence turn-on detection of H 2 O 2 and glucose.

Glucose Sensor Using Redox Active Oligonucleotide-Templated Silver Nanoclusters

“…However, the findings of this study suggest that these two peaks might be caused by different oxidation states, with no size change. A number of groups who used NC/NPs as glucose sensors saw an irreversible PL/absorbance shift or quenching caused by NC/NPs agglomeration or disintegration [20,23,30,31]. In contrast, the Ag NCs in this study had a reversible PL change, which is advantageous for use as a cheaper, reusable sensor.…”

“…The H 2 O 2 detection limit for these Ag NCs was 0.025 µM, well below the glucose concentration in human blood [30]. Polymethacrylic acid and sodium salt (PMAA) and polyvinylpyrrolidone (PVP) templated, red-emissive Ag NCs acted as a turn-on detector for H 2 O 2 and glucose, so that the PL was enhanced with increasing glucose concentration in the range of 0.01–0.5 mM, attributed to NC etching [31].…”

Synthesis of highly stable fluorescent poly(methacrylic acid-co-itaconic)-protected silver nanoclusters and sensitive detection of Cu2+

“…Studies were rst performed to investigate the effects of different metallic ions, including Ba 2+ , Ca 2+ , Cd 2+ , Co 2+ , Cu 2+ , Fe 3+ , K + , Mg 2+ , Zn 2+ , Mn 2+ , and Pb 2+ , on the uorescence intensity of P(MAA-co-IA)-protected AgNCs solution. 19,33 As shown in Fig. 5A, the uorescence intensity of the AgNCs is greatly quenched in the presence of Cu 2+ , while that of the AgNCs is almost unchangeable in the absence of Cu 2+ (see ESI, Fig.…”

“…18 To date, AgNCs synthesized by using polyelectrolyte template containing carboxylic functional groups possess high uorescence and great stability because the carboxylic groups can not only bind the metal ions but also manipulate the conformation of the polymer according to different pH solutions. [19][20][21][22] As we all know, copper, as one of the most fundamental trace elements and a vital cofactor for many enzymes in the human body, plays an irreplaceable role in some physiological processes. 12,13,18 Abnormal copper content may cause negative effects on human health and even serious diseases, such as Alzheimer's disease, Parkinson's disease, and motor neuron disease.…”

Sensitive Hg2+ Ion Detection Using Metal Enhanced Fluorescence of Novel Polyvinyl Pyrrolidone (PVP)-Templated Gold Nanoparticles

“…Tang et al detected Hg 2þ by aggregation quenching, which caused by the interaction of Hg 2þ and carboxyl groups of polymethacrylic acid sodium salt (PMAA). 26 Guan et al synthesized Au NPs using an electrostatic self-assembly technique between negatively charged poly (g-glutamic acid) (PGA) and positively charged CTAB-capped Au NPs; then they used the absorbance ratio(A 750 /A 580 ) to quantify the Hg 2þ concentration with a sensitivity of 1.9 nM. 27 Shen et al 28 used fluorescence intensity of the oxidation products of o-phenylenediamine to quantify Hg 2þ concentration.…”