MWCNT modified Ni–Fe LDH/BiVO 4 heterojunction: boosted visible-light-driven photoelectrochemical aptasensor for ofloxacin detection

Sensitivity and selectivity, which can be identified by the photosensitivity of materials and the identification of elements, are two important factors for a photoelectrochemical aptasensor (PEC aptasensor). Herein, a patent PEC aptasensor for specifically detecting ofloxacin (OFL) was exploited, and a visible-light-active MWCNT/LDH/BiVO 4 heterostructure was introduced as a photoactive material and identification elements, respectively. The combination of LDH with BiVO 4 enhanced the photocurrent response, and MWCNT provided higher electron conductivity, which are advantageous for structuring PEC sensors. Furthermore, the two-pot synthesis of MWCNT/LDH/BiVO 4 has the advantage of possessing an environmentally friendly character. Under optimal conditions, the photocurrent response of MWCNT/LDH/BiVO 4 presents a linear trend with OFL concentration from 0.1 to 16 000 nM, and the limit of detection (S/N = 3) is as low as 0.03 nM. This new PEC sensing device afforded an ultra-sensitive sensor which has high selectivity and stability for detecting OFL.