Lubricin (PRG4) antifouling coating enables the development of an immunosensor for the detection of nerve growth factor in cell culture media

Growth factors (GFs) are the unique signaling molecules that enable constant communication and feedback between cells, modulating cell behavior and maintaining the structure and function of tissues. Traditional methods to detect and quantify GFs, such as ELISA, offer high specificity but are usually costly, present lower limits of detection, typically require sample processing, and are time-consuming. Electrochemical sensing emerges as a promising alternative due to their rapid responses and easy operation; however, they are prone to biofouling when challenged in complex biological environments. This study introduces an antifouling agent, lubricin (LUB), into an electrochemical immunosensor for the detection nerve growth factor (NGF). Through the combination of a specific NGF antibody with LUB, the developed sensor presents a great sensitivity, achieving a limit detection of 0.59 ng mL-1 for the target NGF. Our results show that the proposed sensing configuration can detect NGF directly in unprocessed and undiluted cell culture media with much faster analytical responses when compared to ELISA.