Improvement of the O2 detection: Substituent’s effect on Pd(II) mesotetraphenylporphyrin probes

Abstract

Luminescence-based sensors are among the most promising tools for detection of oxygen gas. Improving the performance of such sensors is still an issue that requires an optimization of its composition which includes an oxygen sensitive probe embedded in a polymeric matrix with or without additives. Our approach is based on design of oxygen sensitive probes and aims at understanding the relationship between the structural variation of the probe and its oxygen sensing ability. In this context, our choice focuses on a non-symmetric palladium meso-tetraphenylporphyrin bearing three electron donor hexyloxy (-OC6H13) and one electron withdrawing phenylacetylide substituents (3-Pd). Poly (trimethylsilyl propyne) [poly(TMSP)] was privileged as polymeric matrix material due to is high oxygen permeability, also silver nanoparticles (AgNPs) were added to magnify the sensor sensitivity. The AgNP supported 3-Pd-doped poly(TMSP) microfiber [AgNP-(3-Pd)MF] in its optimal composition shows an exceptional intensity ratio value I0/I100 = 335, a high Stern-Volmer constant (KSV = 6.4274%−1), a short response time (2 s), and quite low limit of detection (4.66 × 10-4 %−1).