Reaction-based conjugated polymer fluorescent probe for mercury(II): good sensing performance with "turn-on" signal output

Based on a Hg2+- promoted deprotection reaction of dithioacetal, the conjugated polymer PDT was designed. PDT exhibited significant fluorescence enhancement along with an apparent red-shift upon the addition of mercury ions. Due to the specific chemical reaction, the response was very fast with good selectivity towards Hg2+. Other metal ions, including K+, Na+, Li+, Ba2+, Mg2+, Pb2+, Ca2+, Mn2+, Fe2+, Co2+, Fe3+, Cu2+, Ni2+, Al3+, Cd2+, Cr3+, and Zn2+, had nearly no influence on the sensing process. Moreover, PDT showed high sensitivity with the detection limit of 1.0 x 10(-6) mol L-1 and 1 x 10(-5) mol L-1 in solution and as test strips, respectively, as a result of the molecular wire and signal amplification effects.