Low fouling electrochemical sensing interfaces based on Bovine serum albumin hydrogel for the detection of protein biomarkers in human serum

The development of electrochemical biosensor capable of detecting specific biomarkers in real complex biological samples remains a challenge significantly relevant to a range of disease diagnostic applications. Herein an antifouling electrochemical biosensor suitable for biomarker detection in human serum was constructed based on protein hydrogels. A typical protein bovine serum albumin (BSA) was crosslinked with glutaraldehyde to form a hydrogel, which was freeze-dried and re-swollen to exhibit excellent antifouling capability. The rheological testing revealed that the prepared BSA hydrogel possessed good elasticity with a critical strain value of about 600 %, which is important for the construction of stable hydrogel-based biosensors. Following the immobilization of CA125 antibodies onto the BSA hydrogel modified electrode, an electrochemical biosensor for the detection of CA125 was constructed, with a linear range of 0.1 similar to 1000 U mL(-1) and a limit of detection of 0.026 U mL(-1). Owing to the unique properties of the BSA hydrogel, the biosensor exhibited good stability and excellent antifouling performances, and it was able to detect CA125 in human serum with acceptable accuracy. The strategy of constructing low fouling biosensors based on hydrogels prepared from BSA with biocompatibility and widespread availability represented a very promising advance along the road to develop biosensing devices with robust operation in complex biological fluids.