Polyacrylic acid/polyethylene glycol hybrid antifouling interface for photoelectrochemical immunosensing of CYFRA 21-1 based on TiO2/PpIX/Ag@Cu2O composite.

A photoelectrochemical (PEC) transducer based on composite TiO2/PpIX/Ag@Cu2O was prepared for the detection of CYFRA 21-1. TiO2 nanomaterials were synthesized by hydrothermal method. TiO2/PpIX/Ag@Cu2O composites were obtained by combining protoporphyrin Ⅸ (PpIX) molecules and Ag@Cu2O on TiO2. This composite material has strong absorption in visible light region and excellent photoelectric chemical properties. Ascorbic acid (AA) is a good electron donor, which can remove photogenerated holes in liquid environment to inhibit the recombination of photogenerated electrons and hole pairs, thus enhancing the photocurrent and improving its stability. The results showed that the sensor can quantitatively test CYFRA 21-1 in the range of 0.1 pg/mL∼100 ng/mL. The photoelectric chemical sensor has the advantages of high sensitivity, low detection line limit and wide linear range.