A SYBR Green I-based aptasensor for the label-free, fluorometric, and anti-interference detection of MeHg

Methylmercury (MeHg⁺) is a common form of organic mercury that is substantially more toxic than inorganic mercury and is more likely to accumulate in organisms through biological enrichment. Therefore, developing a method to enable the specific and rapid detection of MeHg⁺ in seafood is important and remains challenging to accomplish. Herein, a rapid, label-free fluorescence detection method for MeHg⁺ determination was developed based on SYBR Green I. The detection system implemented "add and measure" detection mode can be completed in 10 min. Under optimal assay conditions, the detection platform showed a linear relationship with the concentration of MeHg⁺ within 1-50 nM (Y = 8.573x + 42.89, R² = 0.9928), with a detection limit of 0.3218 nM. The results obtained for competitive substances, such as inorganic mercury ions and anions, show a high specificity of the method. In addition, this method successfully detected MeHg⁺ in seawater and marine products, with an accompanying spike recovery rate of 96.45-105.1%.