Design and implementation of an optical oxygen sensor based on thermally activated delayed fluorescence organic materials

Abstract

This paper presents the design and implementation of an optical oxygen sensor based on thermally activated delayed fluorescence (TADF) organic materials. The sensing principle relies on oxygen-induced quenching of delayed fluorescence, which results in measurable variations of emission intensity and decay time. The proposed sensor employs a thin-film TADF layer embedded in a Zeonex polymer matrix, providing high optical transparency and oxygen permeability. The photoluminescence response was analyzed using the Stern–Volmer model to evaluate the quenching behavior and sensitivity of the device. An experimental setup was constructed using a CMOS color photodetector, a UV excitation source, and a microcontroller-based interface for real-time data acquisition. The system enables visual detection of oxygen concentration through distinct emission color changes—from green to blue—corresponding to different quenching levels. The obtained results confirm high reproducibility, rapid response, and stability during multiple measurement cycles. These features make the structure a promising platform for compact, low-cost optical sensors applicable in environmental monitoring, food storage, and biomedical diagnostics.