Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Meilong RD 130, Shanghai 200237, China.
Analyst. 2011 Nov 7;136(21):4558-62. doi: 10.1039/c1an15632b. Epub 2011 Sep 23.
A flexible nanoparticle-based sulfate assay is demonstrated in which the positively-charged gold nanoparticles (cysteamine-AuNPs) act as indicator. The aggregation of cysteamine-AuNPs is selectively induced by sulfate, which allows the rapid colorimetric sensing of sulfate without any precipitant, sample preparation and specific instruments. In this work, the cysteamine-AuNPs probe has been successfully applied to the colorimetric detection of sulfate and demonstrates superior sensitivity with a detection limit of sulfate of ~50 ppb. A surprise finding is that the proposed probe can achieve the goal of real-time monitoring and translating a redox process into an appreciable color change via the aggregation of nanoparticles. This is a novel application of a positively-charged AuNPs-based nanoprobe for sulfate detection, kinetic study of the redox process, and opens up new opportunities for design of more novel colorimetric strategies and expansion of AuNPs-based application in different fields.
一种基于金纳米粒子的灵活硫酸根检测方法，其中带正电荷的金纳米粒子（半胱胺修饰的金纳米粒子）可作为指示剂。硫酸根能选择性诱导半胱胺修饰的金纳米粒子聚集，从而无需沉淀剂、样品制备和特定仪器即可实现快速比色检测硫酸盐。在这项工作中，半胱胺修饰的金纳米粒子探针已成功应用于硫酸盐的比色检测，其检测限达到约 50 ppb，具有优异的灵敏度。一个意外的发现是，该探针可以通过纳米粒子的聚集来实现实时监测和将氧化还原过程转化为明显的颜色变化的目标。这是一种新型的基于带正电荷的 AuNPs 纳米探针在硫酸盐检测、氧化还原过程动力学研究中的应用，为设计更多新颖的比色策略以及扩大 AuNPs 在不同领域的应用开辟了新的机会。
