A novel glucose sensor using lutetium phthalocyanine as redox mediator in reduced graphene oxide conducting polymer...

Herein, we report a scalable synthesis of multifunctional conducting polyacrylic acid (PAA) hydrogel (MFH) integrated with reduced grapheme oxide (rGO), vinyl substituted polyaniline (VS-PANI) and lutetium Phthalocyanine (LuPc₂) as three dimensional robust matrix for glucose oxidase (GOx) immobilization (PAA-rGO/VS-PANI/LuPc₂/GOx-MFH). We have integrated the multicomponents such as PAA with rGO, and VS-PANI through free radical polymerization using methylene bis-acrylamide, and ammonium persulphate as the cross linker and initiator. The LuPc₂ was then doped to form multifunctional hydrogel (PAA-rGO/VS-PANI/LuPc₂-MFH). Finally, biosensor was fabricated by immobilizing GOx into PAA-rGO/VS-PANI/LuPc₂-MFH and subsequently used for electrochemical detection of glucose. The PAA-rGO/VS-PANI/LuPc₂/GOx-MFH biosensor exhibited high sensitivity (15.31μAmM^-1cm^-2) for the detection of glucose over a concentration range of 2-12mM with a low detection limit of 25µm. The PAA-rGO/VS-PANI/LuPc₂-MFH biosensor showed a fast response time (1s) to the addition of glucose with high storage stability of 3 months. The real sample analysis reveals that PAA-rGO/VS-PANI/LuPc₂/GOx-MFH could be effectively used as an electrochemical biosensor in industrial as well clinical diagnosis.