Development of an electrochemical biosensor for Galectin-3 detection in point-of-care

Abstract

This research work aims the development and optimization of an electrochemical biosensor based on molecularly-imprinted polymers [MIPs], for monitoring a melanoma biomarker, Galectin-3 (Gal-3). As it is a multifunctional protein that plays an important role in different types of tumors including melanoma, and has shown good results as a potential biomarker in several areas, the construction of a biosensor for the detection of this protein would be a simple and quick strategy to support the treatment of this type of pathology. The target molecule was recognized by a MIP material, created on the electrodes surface by electropolymerizing a mixture of analyte (Gal-3) and monomer (2-aminophenol). Then, the protein was removed from the polymeric material by oxalic acid treatment. This process formed a non-conductive polymer with recognition sites showing affinity for the Gal-3. The control of the surface modification was monitored by Raman spectroscopy and electroanalytical techniques, namely electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The analytical performance of the sensor was evaluated by EIS, by following the analytical response of standard solutions ranging from 0.5 ng/mL to 5000 ng/mL Gal-3 in spyked serum. In general, the biosensor displayed good analytical features, considering limit of detection, response time and reproducibility. Overall, this study resulted from the need to create a new strategy for monitoring melanoma through the creation of a cheaper, faster and sensitive device, which can be commercialized and thus integrate the entire process associated with the treatment and follow-up of this pathology.