Electrochemical sensor based on molecularly imprinted polymer for rapid quantitative detection of brain-derived neurotrophic factor

Abstract

Neurodegenerative disorders necessitate early detection for timely diagnosis and treatment. Here, we present an electrochemical sensor comprising a robust biomimetic receptor, a molecularly imprinted polymer (MIP), integrated with a system of thin film metal electrodes for rapid detection of brain-derived neurotrophic factor (BDNF) as a potential neurodegenerative disorder biomarker. The MIP-based sensor utilizes the surface imprinting approach, where controlled polymer growth around the protein template creates geometrically-fit imprinted sites on the receptor surface. Following thorough characterization, the performance of the sensor was studied by differential pulse voltammetry. Under optimal conditions, the sensor exhibits an impressive limit of detection of 9 pg/mL for BDNF, showing over 5-fold selectivity against closely related neurotrophic factor proteins (CDNF and MANF) and 30-fold selectivity against proteins with similar pI values (e.g., CD48). Competitive binding assays further confirmed the sensor's selectivity, with BDNF inhibiting the binding of interfering proteins. Successful validation of BDNF detection in complex biological samples, specifically fetal bovine serum, highlighted the sensor's potential for real sample analysis. Compared to conventional biosensors, the presented strategy could unlock a new route to develop a highly desirable, robust sensing platform with strong affinity, specificity, and cost-effectiveness for diagnosing neurodegenerative disorders.