Self-powered photoelectrochemical aptasensor based on AgInS₂@Co/Ni-UiO-66@CDs photoelectrode for estradiosl detection

A self-powered photoelectrochemical (PEC) aptasensor was constructed to sensitively detect 17β-estradiol (E₂). Firstly, a reasonable AgInS₂@Co/Ni-UiO-66@Carbon Nanodots (CDs) photoelectrode with excellent photoelectrochemical performance was built by a simple two-step preparation method. The Co and Ni doping markedly improved the activity of UiO-66; the matched energy level of AgInS₂ and Co/Ni-UiO-66 promoted the separation of electron-hole pairs, and the coupling of CDs further enhanced the conductivity and light utilization. Therefore, a steady anode-photocurrent signal output was obtained in 0.0 V bias voltage, providing a reliable photoelectric translating platform for assembling a self-powered PEC aptasensor. The E₂-aptamer was adopted as a recognition unit to enhance the selectivity and sensitivity of the proposed aptasensor. The specific recognition reaction between E₂ and aptamer administering to a raised photocurrent signal and the concentration of E₂ was quantified by counting the fluctuation of the anode-photocurrent signal. The linear response range of the PEC aptasensor was 1.0 × 10^-5-10 nmol/L, and the detection limit (S/N = 3) was lower than 3.0 fmol/L under optimal conditions. The fabricated aptasensor exhibited admirable selectivity, high sensitivity, rapid response, and wide linear range, demonstrating an extensive application prospect for environmental endocrine disruptor detection.