A flexible electrochemical sensor modified by graphene and AuNPs for continuous glucose monitoring

This paper proposed a polyimide based flexible electrochemical sensor with the structure of three electrodes which could be integrated into a PDMS based microfluidic chip for personalized continuous glucose monitoring in subcutaneous interstitial fluid (ISF). The working electrode of the electrochemical sensor was modified by graphene and gold nanoparticles (AuNPs) to improve the glucose measurement resolution. The experimental result demonstrated that the proposed sensor can precisely measure glucose in the linearity range of 0~40mg/dL, the limit of the detection is 0.3mg/dL (S/N=3) which exhibited the potential for hypoglycemia detection in clinics. The sensor was integrated with a microfluidic chip which could be used for extracting and collecting ISF transdermally to form a wearable single-chip device. The device could realize continuous glucose monitoring in the transdermally extracted ISF which avoided the influence of foreign body reaction and the signal drift of current caused by the bioelectricity in human body for the implantable enzyme electrode sensors.