PtNPs decorated chemically derived graphene and carbon nanotubes for sensitive and selective glucose biosensing

Abstract

A hybrid glucose biosensor was developed based on glucose oxidase immobilized on platinum nanoparticles (PtNPs) decorated chemically derived graphene (CG) and carbon nanotube electrode platform for highly sensitive and selective glucose sensing. Chemically derived graphene and carboxylic groups functionalized multiwalled carbon nanotubes composite (C@MWCNTs) were synthesized using one step solvothermal technique to result in a suspension of the synthesized nanocomposite. The nanocomposite solution was drop casted on the gold electrode to form a thin film onto which PtNPs was electrochemically deposited. Glucose oxidase was immobilized on the nanostructured electrode and subsequently coated with nafion for selective glucose sensing. The fabricated hybrid biosensor exhibited good electrocatalytic activity towards glucose with a linear dynamic range of 0.5 mM to 13.5 mM with a fast response time of <5 s. A high sensitivity of 26.5 μA/mM cm2 and a low detection limit of 1.3 μM were observed. The biosensor exhibited a negligible response to common interference species such as uric acid, ascorbic acid and acetaminophen. The pH profile of the hybrid biosensor revealed an optimal pH operating range of 6.5 to 7, whereas the temperature profile revealed increasing oxidation current response with the increase in temperature. The obtained results thus indicate that the nanostructured composite material offers a large surface area and high electrocatalytic activity towards glucose and is a potential candidate material for glucose biosensors.