OBJECTIVETo prepare a zinc porphyrinated polyimide nanofibrous membrane for rapid detection of trace amount of ammonia.

METHODSZinc porphyrin chromophore was copolymerized into polyimide backbones and the according nanofibrous membrane was prepared by electrospinning technique. Ammonia detection was achieved by recording the color and spectral changes of the membrane before and after exposing to the target gas. The sensitivity, selectivity and detection limit of prepared membrane were further studied.

RESULTSThe obtained nanofibrous membrane preserved typical photophysical properties of zinc porphyrin chromophores. When exposed to ammonia, a dual chromo and spectrum responses of the nanofibrous membrane were observed. The binding affinity constant and the detection limit of zinc porphyrinated polyimide nanofibrous membrane calculated from surface plasmon resonance (SPR) analysis and UV-vis were 3.33 X10³ L/mol and 3.13 mg/m³, respectively.

CONCLUSIONThe membrane prepared in this study exhibits good sensitivity, selectivity and reproducibility towards ammonia detection.