Article Enzymes glucose oxidase Bio-sensor platforms Biosensing Techniques Biosensing applications Biosensors Canavalia Chemical sensors Copper Enzymes, Immobilized Equipment Design Field effect transistors Field-effect transistors Graphene Graphene transistors Graphite Heavy metals Humans Hydrolysis of ureas Layer-by-layer assemblies Limit of Detection Long term stability Metabolism Nanoparticles Oxides PEDOT Polyelectrolyte multilayer Polyelectrolytes Proteins