Fabrication of a novel molecularly imprinted biosensor assisted by multi-way calibration for simultaneous determination of cholesterol and cholestanol in serum samples

Abstract

For the first time, a novel and very interesting methodology has been developed based on fabrication of a novel electrochemical biosensor assisted by multi-way calibration methods for simultaneous determination of cholesterol (CL) and cholestanol (CS). A screen printed carbon electrode (SPCE) was chosen as a platform and gold nanoparticles (Au NPs) were electrodeposited onto its surface. Molecularly imprinted polymers (MIPs) from methacrylic acid, ethylene glycolmethacrylate, 2,2-dimetthoxy-2-phenyliacetonephenon, CL and CS have been successfully synthesized by using the photopolymerization method and then, the MIPs were integrated with multiwalled carbon nanotubes (MWCNTs) and casted onto the surface of Au NPs/SPCE to fabricate the biosensor at its final structure. Modifications applied to the SPCE were characterized electrochemical and spectroscopic methods. When the biosensor was in contact with a binary solution of CL and CS, the CL and CS molecules were embedded within the MIP structure which clogged the pathways within the MIP structure. As a reasonable observation, differential pulse voltammetric (DPV) response of the biosensor in the electrochemical probe solution was changed before and after its incubation in a binary solution of CL and CS. Therefore, by immersing the biosensor in an electrochemical probe solution, its second-order DPV responses were recorded which were used to simultaneous determination of the CL and CS with the help of three-way calibration models constructed by unfolded partial least squares/residual bilinearization (U-PLS/RBL) and multi-way partial least squares/residual bilinearization (N-PLS/RBL). The N-PLS/RBL had a better performance for prediction of the concentrations of CL and CS in synthetic samples which motivated us to couple it with the biosensor for simultaneous determination of the CL and CS in real matrices. Fortunately, co-operation of the MIP and three-way calibration helped us to fabricate a very efficient biosensor with a very good practical performance for simultaneous determination of the CL and CS in real matrices.