Conjugated polymer sensitized hyperbranched titanium dioxide based photoelectrochemical biosensor for detecting AFP in serum

Alpha fetoprotein(AFP) is an important tumor biomarker associated with some diseases, and its accurate determination is very important for clinical detection. In this paper, a novel conjugated polymer(CP) containing multi-carboxylic group was synthesized and used to fabricate photoelectrochemical biosensor based on CP sensitized hyperbranched titanium dioxide for detection of AFP in serum. The prepared materials were characterized by FT-IR, IR, NMR and UV-Vis, respectively. The absorption wavelength of the hyperbranched titanium dioxide shifted from ultraviolet region(365nm) to visible region(395nm) after modified with CP compound. Which is conducive to broaden the application of titanium dioxide in biomedicine field due to reducing protein denaturation . The results showed that the photoelectrochemical biosensor has a good linear range from 0.1 ng•mL −1 to 1.0×10 2 ng•mL −1 with detection limit of 0.03 ng•mL −1 (S/N=3). The proposed biosensor exhibited the good selectivity , stability and high sensitivity for detecting AFP in serum. This strategy is expected to be used to detect AFP in clinical serum.