A fluorescent tool for sensing the battery-pollution event in soil samples based on Zn2+-triggering ratiometric signals

Abstract

The leakage of hazardous substances from batteries leads amount of pollution events for their high toxicity and universal use all over the world. Herein, a fluorescent sensor based on triphenylamine (TPAI) was designed to monitor the battery pollution in the real soil examples. Because Zn2+composes a large part of primary and secondary batteries, TPAI was constructed for high affinity of Zn2+ within an efficient intramolecular charge transfer process that could output an obvious green-to-red (510–600 nm) signal to avoid interference from the background substances. In this way, TPAI showed a low detection limit (4.16 × 10−9 M) and high binding constants towards Zn2+ (2.82 × 1012 M−1). Moreover, TPAI exhibited excellent selectivity for Zn2+ over other metal ions and several common compounds in soil. The sensing mechanism indicated that the selectivity might need to be further optimized through adjusting the bulk of donor segment of TPAI. Then, TPAI was used to discriminate the polluted and unpolluted soil samples through a feasible on-line detection proposal under the self-made mobile platform. Combining with the fluorescent sensors and our mobile platform, we believe this work can provide a practical tool for monitoring the pollution events in diverse environmental examples.