Enhancing charge separation/transfer based on Co(II) doped tubular g-C3N4 for photoelectrochemical atrazine aptasensing

Atrazine (ATZ) is one of the most widely used triazine herbicides with characteristics of easy mobility, high persistence and difficult degradation. Its bioaccumulation causes a serious problem to aqueous environment. Therefore, it is a pressing need for highly sensitive and selective detection of ATZ to deal with water pollution quickly. In this work, Photoelectrochemical (PEC) aptasensor was been formed by Co(II) doped g-C3N4 nanotubes (Co(II)/g-C3N4) for the specific detection of ATZ. The tubular structure can provide multiple light reflection/ scattering channels for rapid and long-distance electron transfer, which is favorable to promote photo-generated carriers separation. The Co(II) is located in the interlayer of g-C3N4, which can modulate the electronic structure and energy band to promote PEC performance of g-C3N4. Due to the specific recognition between aptamer and ATZ, aptamer can be used to enhance the selectivity of sensor. The PEC aptasensor showed a low detection limit (3.33 x10-3 fM) and a broad linear range (1 x10-2 - 1 x103 fM) of ATZ. Furthermore, the PEC aptasensor exhibited excellent selectivity and stability in real water sample. This work not only provides a simplified and cost-effective method for detecting ATZ, but also provides insights into the detection of other pollutants.