Novel PSMA-Coated On-Off-On Fluorescent Chemosensor Based on Organic Dots with AIEgens for Detection of Copper (II), Iron (III) and Cysteine

Herein, a novel on-off-on fluorescent chemosensor for copper (II) ion (Cu(2+)), iron (III) ion (Fe(3+)) and cysteine is developed simply by the nano-precipitation method. The prepared organic dots with AIEgens (AIE dots) are advantageous over other metal ions in detecting Cu(2+), Fe(3+) with high selectivity and sensitivity by forming agglomerations (on-off). The agglomerations formed by AIE dots and Cu(2+) redistributed and the fluorescence was obviously recovered in the presence of cysteine (off-on). This sensor has a wide linear range for Cu(2+), Fe(3+) and cysteine. The fluorescent detection limits of AIE dots are calculated to be 107 nM for Cu(2+), 120 nM for Fe(3+) and 78 nM for cysteine, respectively. These results indicate that the AIE dots can be used as a potential probe for Cu(2+), Fe(3+) and cysteine detection.