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 themeso-tetraphenylporphyrin (H 2 TPP) immobilized in a silicone derivative along with silver nanoparticles(AgNPs) and different ionic liquids (ILs). Emission spectra of the H 2 TTP doped thin film exhibited anincrement due to the formation of an associated complex between H 2 TPP and AgNPs. The offered thinfilms responded to the oxygen in the direction of quenching with extreme sensitivity. Emission and decay-time measurements of the H 2 TPP in thin solid matrices were studied in the concentration range of 0-100%p(O 2 ). Utilization of the porphyrin dye along with AgNPs and ionic liquid as an additive exhibited higheroxygen sensitivity with respect to the additive-free forms and resulted in many advances such as linearresponse, 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 thesensor has been recorded as 90 s.