# An Anthracene-Based Hg2+ Fluorescent Probe with Dithioacetal: Simple Synthesis, High Selectivity and Sensitivity, and Dual-Mode Detection Capability

## TL;DR

This paper introduces a new low-cost, fast, and sensitive method to detect mercury pollution in water using anthracene-based fluorescent probes.

## Contribution

The study presents a novel anthracene-based Hg2+ fluorescent probe with dual-mode detection and high selectivity.

## Key findings

- AN-4S probe has a wide linear response range (0~40 μmol/L) and high sensitivity (4.93 × 10−8 mol/L) to Hg2+.
- The probes can detect Hg2+ using both 'turn-off' and 'turn-on' modes within 1 minute.
- The reaction mechanism was confirmed using 1H NMR, FT-IR, and Job’s curves, showing a 1:1 or 1:2 molar ratio with Hg2+.

## Abstract

With the development of the chemical industry, the threat of mercury pollution to human health is increasing. Therefore, it is necessary to develop a low-cost, convenient and efficient Hg2+ detection method. In this study, anthracene-based Hg2+ fluorescent probes AN-2S and AN-4S were synthesized by a dithioacetal reaction for the rapid and efficient detection of the Hg2+ concentration in water. Through molecular structure design and synthesis route optimization, the complexity and cost of the probe synthesis were greatly reduced. AN-2S and AN-4S had good water solubility, rapid response abilities and anti-interference abilities, and could specifically detect Hg2+ using “turn-off” or “turn-on” detection modes within 1 min. The AN-4S probe showed a wide linear response range (0~40 μmol/L) and high sensitivity (4.93 × 10−8 mol/L) to Hg2+ in 99% aqueous solutions, over a pH range of 5~13. The reaction mechanism between the probe and Hg2+ was determined using 1H NMR and FT-IR spectra and Job’s curves. It was proven that the AN-2S and AN-4S probes react with Hg2+ in a molar ratio of 1:1 or 1:2. The dual-detection mode enabled the probes to be used not only for the accurate quantitative detection of Hg2+ under a fluorescence spectrometer, but also for rapid qualitative analysis using a UV flashlight as a test strip, showing a broad practical application potential.