A fluorescent and colorimetric sensor based on a porphyrin doped polystyrene nanoporous fiber membrane for HCl gas detection

Abstract

A facile fluorescent and colorimetric sensor capable of naked-eye detection of gaseous hydrogen chloride (HCl) was developed. This technology uses the optical probe 5,10,15,20-tetraphenylporphyrin immobilized in a polystyrene nanoporous fiber membrane (TPPH₂-PS NFM) which was fabricated by electrospinning. The surface morphology and porous structures of the TPPH₂-PS NFM were characterized and HCl gas sensing properties of the sensor was monitored by fluorescence spectrophotometry. Exposure to HCl gas causes apparent color change of the sensor from pink to yellow-green. The sample of THF-40 showed the maximum pseudo-second-order rate constant due to its largest specific surface area and pore volume. The detection limit was found to be 46 ppb and the response time was 5 s. The sensor exhibits excellent reversibility and prompt response and recovery which shed light on developing low-cost HCl gas sensing systems.