Key Laboratory of Green Chemistry & Technology of MOE, College of Chemistry , Sichuan University , Chengdu , Sichuan 610064 , China.
Analytical & Testing Center , Sichuan University , Chengdu , Sichuan 610064 , China.
Anal Chem. 2019 Mar 5;91(5):3359-3366. doi: 10.1021/acs.analchem.8b04609. Epub 2019 Feb 11.
A disposable, instrument-free, height readout paper-based analytical device (HR-PAD) based on a paper strip inkjet-printed with CdTe quantum dots (QDs) was developed for the sensitive speciation analysis of Ag and silver nanoparticles (AgNPs). When the paper strip is immersed into a sample solution, capillary action draws it through the surface and any Ag in the solution quenches the fluorescence of CdTe QDs via a cation exchange reaction between Ag and the CdTe QDs, with the height of the quenched band being proportional to the concentration of Ag. In contrast, fluorescence quenching cannot be observed when only AgNPs are present in solution. Thus, the concentration of AgNPs can be obtained by subtracting the Ag content from the total silver determined by the HR-PAD after digestion with HNO. Under optimized conditions, the methodology provides high selectivity, sensitivity, and accuracy for the detection of Ag or AgNPs in various samples, even at concentrations as low as 0.05 mg L. Precisions of 4.5% and 2.2% RSDs were achieved at concentrations of 1 mg L and 7 mg L of Ag, respectively. Compared to conventional methods, this approach is inexpensive and user-friendly and eliminates the need for expensive and sophisticated detection instruments. The practicality of the method was demonstrated via the speciation analysis of AgNPs and Ag in river water and 12 commercial products with satisfactory results.
一种基于纸带上喷墨打印的碲化镉量子点（CdTe QDs）的一次性、无仪器、高度读数的纸基分析器件（HR-PAD）被开发出来，用于银和银纳米颗粒（AgNPs）的灵敏形态分析。当纸条浸入样品溶液中时，毛细作用将其吸入表面，溶液中的任何 Ag 通过 Ag 与 CdTe QDs 之间的阳离子交换反应猝灭 CdTe QDs 的荧光，猝灭带的高度与 Ag 的浓度成正比。相比之下，当溶液中仅存在 AgNPs 时，无法观察到荧光猝灭。因此，通过 HR-PAD 在 HNO 消解后测定的总银减去 Ag 含量，就可以得到 AgNPs 的浓度。在优化条件下，该方法在各种样品中对 Ag 或 AgNPs 的检测具有高选择性、灵敏度和准确性，即使在低至 0.05 mg/L 的浓度下也是如此。在 1 mg/L 和 7 mg/L 的 Ag 浓度下，分别获得了 4.5%和 2.2%的 RSD 精度。与传统方法相比，该方法成本低廉、易于使用，并且消除了对昂贵和复杂的检测仪器的需求。通过对河水和 12 种商业产品中的 AgNPs 和 Ag 的形态分析，证明了该方法的实用性，结果令人满意。
