A sensitive aptasensor based on molybdenum carbide nanotubes and label-free aptamer for detection of bisphenol A.

To specifically and sensitively identify bisphenol A (BPA) with a simple and rapid method is very important for food safety. Using an anti-BPA aptamer and MoC nanotubes, we developed a label-free and low-background signal biosensor for BPA detection. The anti-BPA aptamer drastically increased the fluorescence signal of N-methylmesoporphyrin IX under an assistance of Help-DNA. Additionally, BPA can interact with the anti-BPA aptamer and switch its conformation to prevent the formation of a G-quadruplex, resulting in fluorescence quenching. Simultaneously, MoC nanotubes can reduce the background signals due to the adsorption of Help-DNA on their surface. This method shows a linear range of 2-20 nM with a detection limit of 2 nM for detecting BPA. This label-free BPA aptasensor with low background signal is inexpensive, easy to use, and can be applied to determine BPA in real water samples. Graphical Abstract A low-background and label-free biosensor was designed based on MoC nanotubes and aptamer for BPA detection.