基于量子点荧光传感对银及银纳米颗粒分析方法研究

A Simple Approach for Speciation Analysis of Silver Ions and Silver Nanoparticles by CdTe QDs

纳米银由于其具有优异的杀菌活性,在日常生产生活中被大量生产并得到广泛应用。然而在纳米银生产、使用过程中,不可避免地会被释放到环境中,对人体的健康、生存环境等造成潜在危害。目前,纳米银的毒性机理尚不明确,但许多研究表明其毒性可能与纳米银容易被氧化从而释放出银离子密切相关[1]。因此,为了科学评价纳米银的暴露风险和进一步了解纳米银的毒性机制,需建立有效的、简单的同时测定银和纳米银的方法[2]。在前期的银纳米形态分析工作基础上[3],本实验中我们发展出一种新型碲化镉量子点荧光传感分析法用于环境水样中银及银纳米的形态分析。利用银及银纳米对量子点荧光响应的差异(银离子能猝灭量子点荧光,而纳米银则不能),通过测定银离子的浓度及总银浓度从而实现环境样品中银及银纳米含量的准确测定。分析方法检出限达0.03ng·mL-1,RSD为2.4%(n=11)。该方法灵敏度高、简单、无需任何色谱分离,已成功用于环境河水样品分析之中。

We developed a simple approach for speciation analysis of Ag+and Ag nanoparticles(AgNPs)based on CdTe nanocrystals.The fluorencence of CdTe QDs was quenched in less than one minute simply by mixing the nanocrystals with Ag+solution at room temperature,while this reaction did not occur when only silver nanoparticles presented.Based on this striking difference,an ultrasensitive and simple method was developed for speciation analysis of Ag+and AgNPs in complex matrices without any preconcentration or extraction procedure.The proposed method retains several unique advantages of sensitivity,speciation analysis,organic reagent-free and simplicity,and has been successfully utilized for speciation analysis of Ag+and AgNPs in environmental water samples.