Multiple Logic Fluorescent Thermometer System Based on N-Isopropylmethacrylamide Copolymer Bearing Dicyanomethylene-4H-pyran Moiety

The development of polymeric systems that can integrate individual basic logic gates into combinational circuits has been extremely interesting as smart materials. A novel thermometer fluorescent sensor poly(NIPMAM-co-MDCPDP) consisting of N-isopropylmethacrylamide (NIPMAM) as a thermoresponsive unit and dicyanomethylene-4H-pyran derivative as a dipolar-sensitive fluorophore unit was designed. Poly(NIPMAM-co-MDCPDP) performs fluorescence quenching merely by coordination with Cu2+ ions or increasing temperature in neutral or acid aqueous solution. The ON-OFF fluorescence response of poly(NIPMAM-co-MDCPDP) is driven by a temperature-induced phase transition from coil to globule and the capture of Cu2+ ions, resulting in a decrease of the ICT efficiency in neutral solution. The combinational serial NOR logic operation as well as two INHIBIT logic gates was constructed with three inputs: various pH, temperature change, and Cu2+ ions. The proposed combinational