A strategy to Employ Polymerised Riboflavin in the Development of Electrochemical Biosensors

Electrochemically polymerised riboflavin (PRf) film was applied in development of glutamate and hypoxanthine biosensors using appropriate oxidases as recognition elements. PRf served as an enzyme immobilisation matrix composed of natural monomer and as a redox mediator. The PRf film was deposited on glassy carbon electrode (GCE) or on the laser-designed microstructures of the chitosan-graphene oxide (Chit-GO) film deposited on glass slide, which served as a chip sensor. The redox polymer was stable and efficient mediator, however, Chit-GO was placed on the top of PRf/GCE in order to increase the response signal. Such an approach allowed to extend the stability of glutamate and hypoxanthine biosensors to at least 1 month and 15 days, respectively. The chip microelectrode was a single use disposable biosensor due to insufficiently good Chit-GO adhesion on the top of the cover-glass. The glutamate microbiosensor had extremely high sensitivity of 16 μA cm−2 μmol L−1.