School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, PR China.
College of Food and Biological Engineering, Jimei University, Xiamen, 361021, PR China.
Anal Chim Acta. 2022 May 29;1209:339832. doi: 10.1016/j.aca.2022.339832. Epub 2022 Apr 14.
The widespread applications of sulfur dioxide and its derivatives is a double-edged sword in terms of ensuring environmental and food safety. In this work, a recyclable flexible upconversion-luminescence sensor was developed for the determination of sulfite in environmental and foodstuff samples. The upconversion nanoparticles (UCNPs) were uniformly doped with polydimethylsiloxane (PDMS) prepolymer and moulded to prepare a flexible upconversion-luminescence substrate, which was further modified with pararosaniline (PRA) dye based on the typical carbodiimide coupling procedure. The principle of the work was based on the inner filter effect (IFE) mechanism between PRA dye and UCNPs. In the presence of target sulfite ions, it selectively binds to PRA moieties fixed on the surface of the flexible sensor, resulting in its bleaching and restoration of the upconversion fluorescence. Under the optimized conditions, a linear response for sulfite concentration in the range of 10-100 nM was obtained. The limit of detection was calculated as 2.24 nM, and the proposed sensor was successfully regenerated and recycled six times. The method was applied in real rainwater samples with spiked recoveries in the range of 94.85%-99.39%, and the coefficient of variation ranged from 1.65% to 4.93%. Hence, the proposed flexible upconversion-luminescence sensor held the attractive potential for efficient sulfite determination in real environmental and food samples.
二氧化硫及其衍生物的广泛应用在确保环境和食品安全方面是一把双刃剑。在这项工作中，开发了一种可回收的柔性上转换发光传感器，用于测定环境和食品样品中的亚硫酸盐。上转换纳米粒子（UCNPs）均匀掺杂聚二甲基硅氧烷（PDMS）预聚物，并成型为制备柔性上转换发光基底，然后进一步通过基于典型的碳二亚胺偶联程序的副品红（PRA）染料进行修饰。这项工作的原理基于 PRA 染料和 UCNPs 之间的内滤效应（IFE）机制。在存在目标亚硫酸盐离子的情况下，它选择性地与固定在柔性传感器表面的 PRA 部分结合，导致其漂白和上转换荧光的恢复。在优化条件下，获得了 10-100 nM 范围内亚硫酸盐浓度的线性响应。检测限计算为 2.24 nM，并且所提出的传感器成功地再生和循环使用了六次。该方法应用于实际雨水样品中，加标回收率在 94.85%-99.39%范围内，变异系数范围为 1.65%-4.93%。因此，所提出的柔性上转换发光传感器在实际环境和食品样品中亚硫酸盐的有效测定中具有吸引力的潜力。
