Development of Highly Sensitive Metal-Free Tetraphenylporphyrin-Based Optical Oxygen Sensing Materials along with ILs and AgNPs

Abstract

An oxygen sensitive optical chemical sensor has been developed based on fluorescence quenching of the meso-tetraphenylporphyrin (H2TPP) immobilized in a silicone derivative along with silver nanoparticles (AgNPs) and different ionic liquids (ILs). Emission spectra of the H2TTP doped thin film exhibited an increment due to the formation of an associated complex between H2TPP and AgNPs. The offered thin films responded to the oxygen in the direction of quenching with extreme sensitivity. Emission and decay-time measurements of the H2TPP in thin solid matrices were studied in the concentration range of 0-100% p(O2). Utilization of the porphyrin dye along with AgNPs and ionic liquid as an additive exhibited higher oxygen sensitivity with respect to the additive-free forms and resulted in many advances such as linear response, improvement in sensor dynamics and extreme sensitivity. Together with additives, the meso-tetraphenylporphyrin-based composites yielded higher Stern-Volmer constant (Ksv), faster response time, and larger linear response range when compared with the additive-free form. The response time of the sensor has been recorded as 90 s