Ratiometric fluorescence detection of Hg2+ based on gold nanocluster/carbon quantum dots nanohybrids

Ratiometric fluorescence sensing methods are widely used in analysis and detection due to their high sensitivity and stability. In this work, a ratiometric fluorescence method for sensitive detection of Hg2+ was established using a gold nanoclusters/carbon quantum dots (AuNCs/CQDs) nanohybrid probe. The AuNCs/CQDs nanohybrids probe were simply constructed by mixing blue-light-emitting gold nanoclusters (AuNCs) with an orange-emissive carbon quantum dots (CQDs). The probe had two fluorescence emission peaks at 434 nm and 561 nm when the excitation wavelength was 375 nm. With the addition of Hg2+, the fluorescence at 434 nm decreased and the fluorescence at 561 nm remained unchanged; the fluorescence intensity ratio Delta(F-434/F-561) and Hg2+ concentration have a good linear relationship in the range of 8.32 x 10(-7) to 7.69 x 10(-5) mol L-1, and the limit of detection (LOD) is 3.58 x 10(-7 )mol L-1. The method was applied in the detection of Hg2+ in cosmetics and wastewater, and has potential applications for detecting Hg2+ in other samples.