Coumarin-based composite material for the latent fingerprint visualization and electrochemical sensing of hydrogen peroxide

Abstract

Owing to their unique advantages of sensitivity, selectivity, and so on, electrochemical sensing methods are gaining importance in recent times. Given the limitations of single-component sensing systems, developing composite materials with two or more distinct components in suitable proportions for sensing applications is the need of the hour. There have been a plethora of attempts in this regard, wherein composite materials are being used as working electrodes for electrochemical sensing applications. In this regard, herein, we report a simple, hassle-free, and cost-effective synthesis of a redox-active organic molecule capable of electrochemically sensing hydrogen peroxide in its aqueous solution state. The limit of detection (LOD) was found to be as low as 5 nmol L⁻¹ in a linear range of 50–500 nmol L⁻¹. The compound was thoroughly characterized using different spectroscopic techniques. The molecule is both electrochemically and optically active, exhibiting fluorescence properties. This fluorescence behavior was employed in developing a latent fingerprint visualization technique. The redox activity of the compound coupled with photoluminescence properties presents a great opportunity to exploit its usage in electrochemical sensing applications.