A paper disk equipped with graphene/polyaniline/Au nanoparticles/glucose oxidase biocomposite modified screen-printed electrode: Toward whole blood glucose determination

In this work, a convenient, fast, low cost, small sample volume and in situ detection of glucose in human whole blood has been developed by using a disposable screen-printed carbon electrode (SPCE) coupled with a paper disk. To perform the assay, the SPCE was modified with graphene/polyaniline/Au nanoparticles/glucose oxidase (Gr/PANI/AuNPs/GOD) biocomposite and then covered by a paper disk impregnated with the sample. After introducing PBS on the paper disk, the electrochemical measurement was carried out. The assay was based on measuring the current decrease of flavin adenine dinucleotide (FAD) in GOD provoked by the enzyme-substrate reaction using differential pulse voltammetry (DPV). The analytical performance was comparable to conventional methods, and covered the full range of clinically relevant concentrations of glucose in whole blood. This new paper-based electrochemical glucose sensor shows promise in applying point-of-care (POC) device in whole blood tests, and particularly being appropriate for use in the developing world and in resource-limited settings.