# Electrochemical synthesis of Betti bases and their application as fluorescent probes for Hg2+ ions

## TL;DR

This paper introduces a green method to synthesize Betti bases and uses them as fluorescent sensors for detecting mercury ions.

## Contribution

The first electrochemical synthesis of Betti bases in deep eutectic solvents and their use as Hg2+ fluorescent probes.

## Key findings

- Compound 4e showed the highest fluorescence intensity among the synthesized Betti base derivatives.
- The fluorescent probe responded linearly to Hg2+ concentrations between 0.2 and 10.0 µM.
- The limit of detection for Hg2+ was 0.041 µM with a Stern-Volmer constant of 2.69 ± 0.07 × 10⁵ M⁻¹.

## Abstract

The present study included the first electrochemical synthesis of Betti bases in deep eutectic solvents as a green and sustainable method of synthesis. The reaction conditions were optimized by varying different factors like time and type of electrode material. The prepared compounds were utilized as fluorescent probe for mercury ions. The fluorescence intensity of the synthesized Betti base derivatives 4a-e was investigated and the highest fluorescence intensity was displayed by compound 4e (the 2-fluorophenyl derivative). The Betti base 4e showed excitation/emission peaks at 368/461 nm, respectively. The Betti based fluorescence was quenched by Hg2+ ions. The fluorescent probe responded linearly to Hg2+ concentration in the range of 0.2 to 10.0 µM. The limit of detection (LOD) was estimated to be 0.041 µM. The Stern-Volmer constant (Ksv) was calculated to be 2.69 ± 0.07 × 105 M-1.