Chemistry

CLC number: O657.3

High-Efficiency Detection for Silver Ions Based on Fluorescence Enhancement of Peptide-Gold Nanoparticles

基于多肽-金纳米粒子体系荧光增强的银离子高效检测

Core Facility of Wuhan University, Wuhan University, Wuhan 430072, Hubei, China

^† Corresponding author. E-mail: zhouxd@whu.edu.cn; jmhu@whu.edu.cn

Received: 12 September 2024

Abstract

Silver ion (Ag⁺) is a highly toxic metal ion, and its monitoring in water or food resources has become extraordinarily necessary within the scope of human health. In the light of the fact of Ag⁺-induced folding structure of specific peptides, an unlabeled and high-selectivity Ag⁺ assay is presented by means of intrinsic fluorescence of peptides. Under the quenching effect of gold nanoparticles (AuNPs), characteristic fluorescence of peptides could be considerably reduced by rapid modification. Along with the Ag⁺ adding, the fluorescence signals of peptide-AuNPs are largely enhanced by the behavior between peptides and Ag⁺. This is basically involving the formation of 4-coordinated complexes, generating the changes of peptides in structure and fluorescence properties. Under this circumstance, the adverse influence of plenty of interfering ions is suppressed, including the toxic Hg²⁺, Pb²⁺. The results highlight that Ag⁺ ions could be selectively recognized as low as 2.4 nmol/L with a linear range of 5 to 800 nmol/L. In comparison with other programs, the given approach declares simplicity, sensitivity, and superior selectivity. Furthermore, the biosensor excels in the practical application in water samples (e.g., lake, tap and drinking water) owing to its non-interference and on-site rapid determination.

摘要

银离子是一种剧毒的金属离子，其检测对于人类的健康安全至关重要。根据银离子诱导特定多肽折叠这一理论基础，我们利用多肽自身的固有荧光，提出了一种无标记、高选择性的银离子测定方法。借助于金纳米粒子的猝灭作用，多肽的固有荧光能得到显著降低。而随着银离子的加入，多肽逐渐与银离子相互作用，发生构型上的变化，此时多肽-金纳米粒子复合体系的荧光信号得以恢复。这些信号变化主要与多肽-银离子形成的四配位化合物有关，从而使多肽的结构与荧光信号发生了明显变化。基于上述原理，该传感体系表现出良好的选择性，并不会受其他离子(包括汞离子和铅离子)的干扰。实验结果表明，该体系对银离子具备高识别性与高专一性，在5 ~ 800 nmol/L的线性范围内可特异性识别银离子，其检出限可低至2.4 nmol/L。与其他传感体系相比，该方法具有简单快速、灵敏高效、选择性好、具备现场快速测定等优势，在水样(如湖泊、自来水和饮用水)的检测中有着广泛的应用前景。