Optical fiber sensors for biocide monitoring: Examples, transduction materials, and prospects

Antifouling biocides are toxic to the marine environment impacting negatively on the aquatic ecosystems. These biocides, namely, tributyltin (TBT) and Cu(I) compounds, are used to avoid biofouling; however, their toxicity turns TBT and Cu(I) monitoring an important health issue. Current monitoring methods are expensive and time-consuming. This review provides an overview of the actual state of the art of antifouling paints' biocides, including their impact and toxicity, as well as the reported methods for TBT and Cu(I) detection over the past decade. The principles of optical fiber sensors (OFS) applications, with focus on environmental applications, and the use of organic chemosensors in this type of sensors are debated. The multiplexing ability of OFS and their application on aquatic environments are also discussed.
The authors would like to gratefully acknowledge the financial. support from Foundation for Science and Technology, I.P (FCT) for the PhD grant SFRH/BD/145639/2019, to the project “SolSensors — Development of Advanced Fiber Optic Sensors for Monitoring the Durability of Concrete Structures”, reference POCI-01- 0145-FEDER-031220 supported by the Program Budget COMPETE — Operational Program Competitiveness and Internationalization — COMPETE 2020 and the Lisbon. Regional Operational Program in its FEDER component and by the budget of FCT and the support of Centro de Química, CQUM, financed by FCT under the project UID/QUI/00686/2020. The authors would like to gratefully acknowledge and recognize the efforts of the two anonymous reviewers for critically reading and providing useful suggestions that were very helpful in improving the manu script readability.