Arginine-passivated MAPbBr3 -embedded PMMA nanofibers for fluorescence-based NH3 sensing

Metal halide perovskite nanocrystals (MHPNCs) have emerged as promising fluorescent sensing materials owing to their excellent optical properties. However, surface defects significantly influence their sensing performance, highlighting the importance of defect passivation for improving sensing capability. In this study, a fluorescent NH 3 sensor film was fabricated via electrospinning, in which arginine(ARG)-modified MAPbBr 3 (MA refers to methylammonium) quantum dots were encapsulated within poly(methyl methacrylate) (PMMA) nanofibers to investigate the effect of arginine passivation on NH 3 sensing performance. Under dynamic gas sensing conditions at 25°C and an ambient relative humidity, the sensor exhibited a concentration-dependent NH 3 response in the range of 1.25–200 ppm. The ARG-modified sensor exhibited an approximately 115% higher sensitivity than the sensor without ARG. The sensor showed a more pronounced response toward NH 3 than interfering gases at 200 ppm. Moreover, the maximum response variation was 3.33% during five consecutive NH 3 sensing cycles, and the fluorescence intensity of the sensor membrane remained above 80% of its initial value after 180 days of storage.