NanoPOP: Solution-processable Fluorescent Porous Organic Polymer for Highly Sensitive, Selective, and Fast Naked Eye Detection of Mercury

Fluorescence-based detection is one of the most efficient and cost-effective methods for detecting hazardous, aqueous Hg2+. We designed a fluorescent porous organic polymer (TPA-POP-TSC), with a “fluorophore” backbone and a thiosemicarbazide ‘’recep-tor” for Hg2+ targeted sensing. Nanometer-sized TPA-POP-TSC spheres (nanoPOP) were synthesized under mini-emulsion condi-tions and showed excellent solution-processability and dispersity in aqueous solution. The nanoPOP sensor exhibits exceptional sensitivity (Ksv = 1.01×106 M-1) and outstanding selectivity for Hg2+ over other ions with rapid response and full recyclability. Furthermore, the nanoPOP material can be easily coated onto a paper substrate to afford naked-eye-based Hg2+-detecting test strips that are convenient, inexpensive, fast, highly sensitive and reusable. Our design takes advantage of the efficient and selec-tive capture of Hg2+ by thiosemicarbazides (BE = -29.84 KJ mol-1), which facilitates electron transfer from fluorophore to bound recepto...