LAUSR

Abstract In view of the possible toxic effects of ofloxacin (OFL) on human health, the design of high-performance photoelectrochemical (PEC) aptasensor is urgently needed for detecting the residual OFL. Herein, a PEC aptasensor using NiFe layered double hydroxide (NiFe LDH)/graphitic carbon nitride (g-CN) heterojunction has been developed for efficient and selective detection of OFL. On one hand, the unique morphology structure with g-CN-wrapped flower-like NiFe LDH can promote the close contact between the two materials and accelerate the electrons transfer. Additionally, the introduction of strongly visible-light-response NiFe LDH flower in heterojunction promotes the visible light harvesting efficiency, which can provide a contrast for that of g-CN. On the other hand, the formation of heterojunction at the semiconductor interface of between NiFe LDH and g-CN can accelerate the effective separation and migration of photoinduced charge, thus greatly increasing the change of photocurrent signal. Based on the satisfactory PEC performance of the heterojunction, OFL-aptamer as specific recognition element was anchored on the modified electrode to fabricate highly specific and selective PEC OFL aptasensor. The developed aptasensor platform possessed linear response in the wide range (0.0001-1 nM) with low limit of detection (LOD, 0.035 pM), anti-interference capability, and high feasibility for monitoring OFL in real water and milk samples. We expect that this simple and low-cost design of PEC aptasensor on the basis of LDHs-based photoactive materials can widen the practical application for determination of environmental pollutants in PEC field.