Portable smartphone integrated paper sensors for fluorescence detection of As(III) in groundwater

Arsenic contamination in groundwater is a supreme environmental problem, and levels of this toxic metalloid must be strictly monitored by a portable, sensitive and selective analytical device. Herein, a new system of smartphone integrated paper sensors with Cu nanoclusters was established for the effective detection of As(III) in groundwater. For the integration system, the fluorescence emissive peak of Cu nanoclusters at 600 nm decreased gradually with increasing As(III) addition. Meanwhile, the fluorescence color also changed from orange to colorless, and the detection limit was determined as 2.93 nM (0.22 ppb) in a wide detection range. The interfering ions also cannot influence the detection selectivity of As(III). Furthermore, the portable paper sensors based on Cu nanoclusters were fabricated for visual detection of As(III) in groundwater. The quantitative determination of As(III) in natural groundwater has also been accomplished with the aid of a common smartphone. Our work has provided a portable and on-site detection technique toward As(III) in groundwater with high sensitivity and selectivity.

地下水砷污染是一类严峻的环境问题，该有毒类金属的含量必须通过便携式、高灵敏且高选择性的分析设备进行严格监测。本研究构建了一种智能手机集成式铜纳米团簇（Cu nanoclusters）纸基传感器新体系，用于高效检测地下水中的三价砷（As(III)）。在该集成体系中，铜纳米团簇在600 nm处的荧光发射峰强度随三价砷添加量的增加而逐渐降低；与此同时，其荧光颜色也由橙色变为无色，且该方法在宽检测范围内的检出限可达2.93 nM（0.22 ppb）。干扰离子不会对三价砷的检测选择性造成影响。进一步地，本研究制备了基于铜纳米团簇的便携式纸基传感器，可实现地下水中三价砷的目视检测；借助普通智能手机，本研究还完成了天然地下水中三价砷的定量测定。本研究为地下水中三价砷的检测提供了一种高灵敏、高选择性的便携式现场检测技术。