A highly sensitive fluorescent probe based on functionalised ionic liquids for timely detection of trace Hg2+ and CH3Hg+ in food

A novel fluorescent probe was fabricated using fluorescein-based ionic liquids (ILs) to effectively achieve rapid and accurate detection of Hg²⁺ and CH₃Hg⁺ in food. A probe developed by addition of modified fluorescein into the functionalised ILs presented a promising sensitivity toward Hg²⁺ and CH₃Hg⁺ at concentrations of 0.4 and 60 nM, respectively. In addition, the novel probe could achieve visual and timely detection of Hg²⁺ and CH₃Hg⁺ by the naked eyes at concentrations of 0.1 and 1 μM, respectively. The probe could also overcome the interference of potential ions and common organic ligands and detect Hg²⁺ and CH₃Hg⁺ in real food samples, such as green tea and liquor. The probe could be converted into a paper-based sensor to visually detect Hg²⁺ and CH₃Hg⁺ at levels as low as 10 nM.