A sensitive photoelectrochemical aptasensor for enrofloxacin detection based on plasmon-sensitized bismuth-rich bismuth oxyhalide

Highly sensitive detection of enrofloxacin (ENR) is crucial for contaminant detection and environmental protection. A sensitive and selective photoelectrochemical (PEC) aptasensor was assembled by Au nanoparticles sensitized Bi24O31Br10 (Au/Bi24O31Br10) composites for detecting ENR. Due to the synergistic effect of bismuth-rich strategy and surface plasmon resonance (SPR) effect, Au/Bi24O31Br10 possessed promoted visible light absorption capacity further enhancing PEC performance and detection sensitivity of the constructed PEC aptasensor. By chemically adsorption effect between the sulfhydryl modified aptamer and Au nanoparticles, the ENR-aptamer was introduced into the PEC sensor to achieve highly selective detection of ENR. The PEC ENR aptasensor based on Au/Bi24O31Br10 composites possessed a broad linear detection scope (0.72–36000 ng L−1), satisfactory limit of detection (0.30 ng L−1, S/N = 3), high selectivity and stability. This work provides a new way for the trace detection of antibiotics in environmental analysis field.