Preparation of a silver nanoparticle-based dual-functional sensor using a complexation–reduction method

Abstract

A dual-functional sensor based on silver nanoparticles was synthesized by a two-stage procedure consisting of a low-temperature chitosan-Ag(+) complexation followed by a high-temperature reduction of the complex to form chitosan-capped silver nanoparticles (CS-capped Ag NPs). The surface plasmon resonance (SPR) absorption and fluorescence emission of the silver nanoparticles were influenced by the concentration and degradation time of chitosan, and the temperatures of the complexation and reduction reactions. The SPR absorption band was blue-shifted while the intensities of emission and absorption were decreased after reacting the silver nanoparticles with Hg(2+) ions. The silver nanoparticles reacted with Hg(2+) were characterized by high resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and surface-enhanced Raman scattering spectroscopy (SERS). The results suggested that the particle growth and aggregation of the silver nanoparticles were caused by the adsorption of Hg(2+) and deposition of Hg(0) on the nanoparticle surface. Direct correlations of the SPR absorption and fluorescence emission with the concentration of Hg(2+) were useful for quantitative analysis of Hg(2+). It was possible to use the dual-functional silver nanoparticles as a colorimetric and fluorescent sensor for sensitive and selective detection of Hg(2+) ions.

Colorimetric optical chemosensor of toxic metal ion (Hg2+) and biological activity using green synthesized AgNPs

“…The biosynthesized silver nanoparticles (AgNPs) are the most preferred due to their cost-effectiveness, eco-friendliness, and ease of synthesis and have various most effective applications such as in catalysis, antibacteria, nonlinear optics, as optical receptor, bio-labeling, as coating for solar energy absorption, for electrical batteries, therapeutic, anti-HIV activity (5,6). Generally, various approaches, such as sequential injection (7), reduction (8), irradiation-assisted chemical reaction (9), biosynthesis (10), and physical approaches (11,12), have been reported for the synthesis of different shapes and sizes of AgNPs. The synthesis of AgNPs by chemical reduction method is the most common approach.…”

Biosynthesis and characterization of silver nanoparticles prepared from two novel natural precursors by facile thermal decomposition methods

“…Various methods such as sequential injection15, reduction reaction16, irradiation-assisted chemical reaction17, biosynthesis18, and physical methods1920, etc have been devised for the synthesis of SNPs with different shapes and sizes. Among all the examined approaches, biosynthesis methods have attracted great interest since it is an environmental friendly and facile approach.…”

Silver nanoparticles immobilized onto poly(4‐vinylpyridine)‐functionalized magnetic nanoparticles: A robust magnetically recyclable catalyst for oxidant‐free alcohol dehydrogenation

“…Finally, the mixture was magnetically separated, washed several times with deionized water and then dried at 50°C overnight to afford the SMNP-PVP-Ag catalyst. It is worth noting that the presence of the nitrogen atom of pyridine in the structure of SMNP-PVP can increase the physical adsorption of Ag nanoparticles, [35][36][37] and thus the loading of Ag nanoparticles was about 2.62 wt% with respect to our previous work (about 1.48 wt%). [20] Mechanistic studies of alcohol dehydrogenation using Ag nanoparticles supported on SiO 2 , [38] Al 2 O 3 [27] and Fe 3 O 4 @SiO 2 [20] surfaces indicate that Ag nanoparticles along with the hydroxyl groups available on the surfaces can participate simultaneously in dehydrogenation of alcohols.…”