Proteinases are involved in a multitude of important physiological processes, such as protein metabolism. For this reason, a conductometric enzyme biosensor based on proteinase K was developed using two types of nanoparticles (gold and magnetic). The enzyme was directly adsorbed on negatively charged nanoparticles and then deposited and cross-linked on a planar interdigitated electrode (IDE). T...

We report a conductometric nanoparticle biosensor array to address the significant variation of electrical property in nanomaterial biosensors due to the random network nature of nanoparticle thin-film. Indium oxide and silica nanoparticles (SNP) are assembled selectively on the multi-site channel area of the resistors using layer-by-layer self-assembly. To demonstrate enzymatic biosensing capa...

Urease was immobilized on platinum electrode both by chemical binding and electropolymerization.The conductometric urea biosensor thus prepared showed a detection limit of 4.9×10-5 M and linear dynamic range from 4.9×10-5 to 5.8×10-3 M for urea concentration when the enzyme is covalently immobilized on Pt electrodes. Conductometric transducers respo...

A highly sensitive, fast, and stable conductometric enzyme biosensor for the determination of nitrate in water is described and validated in natural water samples. The nitrate biosensor is based on a methyl viologen mediator mixed with nitrate reductase (NR) from Aspergillus niger and Nafion® cation-exchange polymer dissolved in a plasticized PVC membrane deposited on the sensitive surface of i...