A “Signal On” Photoelectrochemical Aptasensor For Tetracycline Detection Based On Semiconductor Polymer Quantum Dots

A tetraphenylporphyrin (TPP) doped PFBT polymer quantum dots (TP-Pdots) were synthesized via the reprecipitation method for photoelectrochemical (PEC) aptasensor detection of tetracycline (TC). The TP-Pdots exhibit a superior cathode photocurrent signal. TP-Pdots increase the separation of photo-generated charges, and improve photocurrent conversion efficiency, resulting in enhanced photocurrent response. The aptamer was used as a recognition element and TP-Pdots as a photoactive material to prepare a PEC aptasensor for sensitivity detection of TC. The PEC aptasensor was constructed by immobilizing TP-Pdots on ITO electrode and combining it with aptamer by EDC coupling. After the TC reacts specifically with the aptamer, causing the aptamer to fall off from the TP-Pdots /ITO electrodes surface and the photocurrent intensity restored. This PEC aptamer sensor possesses a wide linear range from 1.0 nmol.l −1 to 1.0 × 10 4 nmol.l −1 with the detection limit of 0.26 nmol.l −1 . Meanwhile, the PEC aptasensor was successfully used for the detection of tetracycline in honey.