Highly selective FET-type glucose sensor based on shape-controlled palladium nanoflower-decorated graphene

Abstract

The glucose concentration in human body fluids is main marker for diagnose diabetes mellitus, which is a disease caused by insufficient insulin. Although diagnostic devices based on glucose level in the blood have been commercialized, a non-invasive detection methodology is required. Here, selectivity enhanced field-effect-transistor (FET)-type glucose sensor based on shape-controlled palladium nanoflower-decorated CVD graphene (SPNFG) with glucose oxidase (GOx) and nafion was fabricated using surface functionalization, electrodeposition and spin coating techniques. The surface-functionalized CVD graphene is used as substrate for electrodeposition and a p-type channel for FET-type sensor. The palladium nanoflower (PNF) shape was controlled by adjusting the sulfuric acid concentration in the electrolyte during the electrodeposition. Nafion and GOx layer were deposited onto SPNFG using spincoating method. The GOx/Nafion/SPNFG electrode within FET system was applied to high sensitive and selective glucose sensor. The GOx/Nafion/SPNFG based sensors exhibit high selectiviy for uric acid and ascorbic acid with low minimum detection limit for glucose (1 nM). and The high durability can be expected for the FET-type sensor by virtue of direct decoration of palladium on the CVD graphene surface. (c) 2018 Elsevier B.V. All rights reserved.