Enhanced photoelectrochemical aptasensing triggered by nitrogen deficiency and cyano group simultaneously engineered 2D carbon nitride for sensitively monitoring atrazine

Determination of atrazine (ATZ) residues in aquatic environment has important theoretical and practical significance for protecting the ecological environment and ensuring human health. A photoelectrochemical (PEC) aptasensing based on nitrogen deficiency and cyano group simultaneously engineered two-dimensional (2D) carbon nitride (named as DCN) has been proposed for sensitively detecting ATZ. The introduction of nitrogen deficiency can narrow band gap of DCN, leading to positive position of intermediate electronic state, and improving the absorption of visible light. The intermediate electronic state can function as an electron trap to promote the separation and migration of photogenerated carriers. Cyano groups can trap photoinduced electrons and suppress charge recombination. Gas produced by thermal decomposition has a tailoring effect, endowing DCN with 2D ultra-thin structure, which shortens transmission path of carriers. The synergistic effect of the above enhances PEC performance of DCN. The PEC aptasensing exhibited a wide linear range of 1.0 × 10-4 to 1.0 × 103 pM and a low detection limit of 3.33 × 10-5 pM with excellent selectivity, stability, and satisfactory accuracy during detecting real samples. The proposed design of carbon nitride-based materials may provide a better understanding of the relationship between kind of photoactive materials and PEC performance.