MnO2 Nanospheres Assisted by Cysteine Combined with MnO2 Nanosheets as a Fluorescence Resonance Energy Transfer System for Switch-on Detection of Glutathione

Manganese dioxide nanosheets combined with cysteine-assisted emitting manganese dioxide nanospheres (Cys-MnO2 nanospheres) is fabricated for the first time as an off-on fluorescence detection platform for glutathione (GSH). In this sensing system, Cys-MnO2 nanospheres served as energy donors, while MnO2 nanosheets were used as both energy acceptors and recognition units. MnO2 nanosheets can effectively quench the fluorescence of Cys-MnO2 nanospheres through the fluorescence resonance energy transfer (FRET). The addition of GSH could reduce MnO2 nanosheets into Mn2+, disrupting the FRET process and restoring the fluorescence of Cys-MnO2 nanospheres. Under the optimum conditions, the switch-on platform we established has a wide response to GSH with a range of 5-50 mu M and 150-800 mu M, as well as a superior specificity. Importantly, all components of the sensor are nontoxic, biocompatible, easily prepared, and have a high utilization of raw materials. Moreover, the sensing system achieved satisfactory results in human serum, showing a tremendous potential in the field of biomedicine.

Automated summary

The combination of manganese dioxide nanosheets and cysteine-assisted emitting manganese dioxide nanospheres has been fabricated for fluorescence detection of glutathione. The system achieved wide response range and superior specificity, showing potential in the field of biomedicine.