Flexible dibutyl phthalate aptasensor based on self-powered CNTs-rGO enzymatic biofuel cells

To meet the emerging demand of portable and on-site assay, a self-powered and flexible split-type aptasensor was constructed based on an enzymatic biofuel cell (EBFC) by using a flexible glucose oxidase (GOD)/Bi3Ti2O8F/carbon nanotubes-reduced graphene oxide (Bi3Ti2O8F/CNTs-rGO) film as the anode and the aptamers fixed AuNPs/CNTs-rGO film as the selective cathode. Bi3Ti2O8F with H2O2 enzyme-mimicking property and three-dimensional structure was used for the immobilization of GOD to improve the performance of the EBFC. The recognition of dibutyl phthalate (DBP) was performed in DBP containing solutions using the aptamer/AuNPs/CNTs-rGO cathode, and the detection was carried out in the other glucose containing solution. The output power density of the EBFC decreased after recognizing DBP because of the hindered electron transfer. The aptasensor responded linearly to dibutyl phthalate (DBP) (1.0 × 10−14 to 1.0 × 10−9 mol/L) with a detection limit of 1.99 × 10−15 mol/L. The bending and stretching tests didn't influence the output power density of the EBFC, indicating the stability and flexibility of the aptasensor. This sensor had been successfully applied for water sample analysis. It has the potential to be a useful platform for developing implantable, portable, and miniaturized sensors.