A Fluorescence Strategy for Silver Ion Assay via Cation Exchange Reaction and Formation of Poly(thymine)-templated Copper Nanoclusters

Abstract

The detection of Ag + ions in the environment and biological systems is important to both environmental monitoring and modern medicine. Herein, a novel and label-free method was developed for Ag + detection, which utilizes a florescence strategy combining DNA-templated copper nanoclusters (Cu NCs) with cation exchange reactions. The method is primarily based on the effective detection of an Ag +-triggered cation exchange reaction and the release of free Cu 2+ from CuS nanoparticles (CuS NPs), while the probe T30 serves as an effective template for the formation of fluorescenceinducing Cu NCs. Under optimal conditions, this sensing system displays high sensitivity with a 50 nM limit of detection and a range from 0-100 μM. In addition, the proposed method exhibits high selectivity and, therefore, was successfully applied to the analysis of real samples. Overall, these results demonstrate that our established method has advantages of design and operation simplicity, as well as cost-effectiveness.

Recyclable fluorescence sensing based on copper clusters for simultaneous determination of copper ions and ammonia

“…23,24 In recent years, metal nanocluster-based fluorescent probes have been used for the selective determination of metal ions. 25–29 For example, strategies for Cu 2+ detection have been reported by the formation and aggregation of Cu nanoclusters with glutathione (GSH), bovine serum albumin (BSA), 30–32 etc. In these processes, fluorescent Cu clusters are obtained by reaction between copper ions and reducing agents in organic solvents or alkaline solutions for a period of time.…”

Cascade signal amplification using Hg2+-induced oxidation of silver nanoparticles and cation exchange reaction for ICP-MS bioassay

“…Alternatively, chemical signal amplification which capitalizes on nanomaterials 13 or redox reactions 14 can amplify the output signal in a simple, low-cost and rapid way. For one, the large amounts of ions encapsulated in ionic nanocrystals (such as CuS NPs 15 ) can be released via reaction with certain cations (such as Ag + and Hg 2+ ), called cation exchange reaction (CER), in a fast and gentle way, which is suitable for biological analysis. For example, a research group reported a tertiary signal amplification system consisting of CHA, CER between CuS NPs and free Ag + released from C–Ag–C, and prereduction reactions of Hg 2+ competed with released Cu 2+ from CER to achieve the highly sensitive, fast and homogeneous quantification of mucin 1 and A549 cells.…”