A novel VS2 nanosheet-based biosensor for rapid fluorescence detection of cytochrome c

A novel ultrasensitive sensing system for rapid fluorescence detection of cytochrome c (cyt c) was proposed by combining aptamer-based bioassay with VS2 nanosheets. VS2 nanosheets with high fluorescence quenching ability were synthesized by the solution route. A cyt c-binding aptamer was tagged with the fluorescent dye carboxy fluorescein (FAM), acting as the probe. VS2 nanosheets can adsorb the probe and quench its fluorescence efficiently. However, the fluorescence of the probe was retained when it was incubated with cyt c and then mixed with VS2 nanosheet solution. The proposed sensing system shows high selectivity and sensitivity, giving a linear range of 0.75 nM to 50 mu M, and a limit of detection of 0.50 nM.