Fabrication of a novel molecularly imprinted biosensor assisted by higher-order calibration methods and a computer-generated experimental design for determination of thyroglobulin in the presence of thyroxine and triiodothyronine as uncalibrated interference

Abstract

In this work, a novel electrochemical biosensor was fabricated by modification of a rotating glassy carbon electrode (GCE) with fullerene C60-ionic liquid (C60-IL), and electrochemical synthesis of molecularly imprinted polymers (MIPs) on its surface for selective and sensitive determination of thyroglobulin (TG) in the presence of thyroxine (T4) and triiodothyronine (T3) as uncalibrated interference. The MIPs were synthesized onto the surface of electrochemically activated C60-IL/GCE by electropolymerization of 4-aminothiophenol, methacrylic acid, ethylene glycol dimethacrylate (as cross linker), and TG (as template molecule). By incubation of the biosensor in TG solution, the TGs were entrapped within the pathways of the MIPs, and by incubation of the biosensor in electrochemical probe solution, the pathways for reaching the probe molecules to biosensor were decreased which caused the hydrodynamic differential pulse voltammetric (HDPV) response of the biosensor to be decreased. The effects of experimental parameters on response of the biosensor were optimized by a quadratic central composite design, and at optimized conditions determination of TG in the presence of T4 and T3 as uncalibrated interference was performed. The selectivity of the biosensor was further assisted by supporting the biosensor response with the help of second-order calibration methods and generation of second-order HDPV data with the aim of exploiting second-order advantage. Second-order calibration models were developed by MCR-ALS, PARAFAC2, N-PLS/RBL, and U-PLS/RBL with the aim of choosing the best model for assisting the biosensor for selective determination of the TG in the presence of T4 and T3 as uncalibrated interference. The results confirmed the best performance was observed for the biosensor assisted by PARAFAC2 in both synthetic and real matrices which was comparable with HPLC-UV as the reference method, and can be suggested as an alternative method for chromatographic methods.