Controllable porosities of conjugated microporous polytriphenylamine enable high sensitivity toward trimethylamine at low temperatures
The development of trimethylamine (TMA) gas sensors is crucial for environmental monitoring, food safety, and health surveillance. However, stable detection of TMA at low concentrations and low temperatures remains challenging. In this work, a series of conjugated microporous polytriphenylamine (PTPA) were designed and synthesized with tunable porosity and surface area using Hansen solubility parameters and nanosilica spheres as templates. Compared to pure PTPA (R = 4 for 100 ppm), the modified PTPA derivatives exhibited significantly enhanced TMA sensing performance, with NaF-PTPA achieving a remarkable sensitivity (R = 22 for 100 ppm) and a low detection limit of 0.53 ppm. The NaF-PTPA based sensor also demonstrated excellent long-term stability, maintaining consistent performance over 30 days at 54 °C. The impressive results can be attributed to the protonation (–NH2+), modified porosity and increased surface area. Hence, this strategy presents new insights for the advancement of low-temperature sensing technologies.