Bio-inspired Magnetite/lignin/polydopamine-glucose Oxidase Biosensing Nanoplatform. From Synthesis, Via Sensing Assays to Comparison with Others Glucose Testing Techniques

Glucose monitoring has become a crucial part of diabetes care, and is also of importance in the food industry. However, the measurements are subject to certain limitations and errors. These may result from many factors, including the strip manufacturing process, inappropriate storage, temperature, coding, aging, etc. Here, we discuss the measurement of glucose in real samples using techniques such as photometric assay, glucometers, and using a proposed biosensor. Biosensor platforms based on the multicomponent material magnetite/lignin/polydopamine-glucose oxidase with the addition of ferrocene and a dedicated carbon paste electrode (CPE/FeO/Lig/PDA/GOx/Fc) were fabricated for glucose detection in real, commercially available glucose-based samples. To determine the morphological features of the materials, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), atomic force microscopy (AFM) and zeta potential measurements were carried out. Moreover, to determine the effectiveness of glucose oxidase immobilization the Bradford assays was applied. Analysis of glucose-based products was carried out based on photometric measurements using an AU480 Chemical Analyzer from Beckam Coulter, with the use of three glucometers (Wellion Calla light® WELL 900LB, CERA-CHEK 1Code®Model G400, iXell®Rev.04/10-PL), and with the use of our proposed CPE/FeO/Lig/PDA/GOx/Fc biosensor. Tests on real samples demonstrated the repeatability of the results. The results showed that this biosensor has excellent potential for application in the determination of glucose in various commercial products.