Stern-Volmer mechanistic study on transition metals embedded onto optical fibre for dissolved oxygen sensing and monitoring: A systematic literature review

Abstract

Dissolved oxygen (DO) concentration is the most critical parameter to evaluate water quality, commonly addressed in global freshwater, and seawater aquacultures. Research trends and patterns on optical fibre for environmental DO sensing and monitoring, specifically, photonics, are rising and revolutionilising the current practices. Transition metals have emerged as a promising material for use in determining DO concentration in the water. Their unusual physicochemical and optical properties enable them to be used as an oxygen-sensitive dye and a so-called waveguide in thin-film that can be easily integrated with optical fibre. Thus, the selection of transition metals is important in the early phase of this research to design the optical-based transducers for DO sensing and monitoring. The DO concentration needs to be accurately measured in real-time, as its change is a continuous dynamic process. Gaps were identified utilising various transition metals embedded onto optical fibre for the in-situ determination of DO concentration in the water, contributing new knowledge for future scholarly work. The detection mechanism of DO concentration in the water with various transition metals is briefly outlined and concludes by addressing the real world's laboratory-scale challenges. In short, we focus on the Stern-Volmer model for mechanistic study on transition metals for DO sensing and monitoring.