Abstract: The present disclosure provides an aqueous based electrically conductive ink, which is essentially solvent free and includes a nano-scale conducting material; a binding agent; and an enzyme. In one embodiment, the ink includes at least one of a mediator, a cross-linking agent and a substrate as well. In one further embodiment, the present disclosure provides electrically conductive ink including a single walled, carboxylic acid functionalized carbon nanotube; 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride and N-hydroxy succinimide (NHS) ester; polyethyleneimine; an aqueous buffer; and glucose oxidase.