A glucose biosensor based on novel Lutetium bis-phthalocyanine incorporated silica-polyaniline conducting nanobeads

The facile preparation of highly sensitive electrochemical bioprobe based on lutetium phthalocyanine incorporated silica nanoparticles (SiO₂(LuPc₂)) grafted with Poly(vinyl alcohol-vinyl acetate) itaconic acid (PANI(PVIA)) doped polyaniline conducting nanobeads (SiO₂(LuPc₂)PANI(PVIA)-CNB) is reported. The preparation of CNB involves two stages (i) pristine synthesis of LuPc₂ incorporated SiO₂ and PANI(PVIA); (ii) covalent grafting of PANI(PVIA) onto the surface of SiO₂(LuPc₂). The morphology and other physico-chemical characteristics of CNB were investigated. The scanning electron microscopy images show that the average particle size of SiO₂(LuPc₂)PANI(PVIA)-CNB was between 180-220nm. The amperometric measurements showed that the fabricated SiO₂(LuPc₂)PANI(PVIA)-CNB/GOx biosensor exhibited wide linear range (1-16mM) detection of glucose with a low detection limit of 0.1mM. SiO₂(LuPc₂)PANI(PVIA)-CNB/GOx biosensor exhibited high sensitivity (38.53µAmM^-1cm^-2) towards the detection of glucose under optimized conditions. Besides, the real (juice and serum) sample analysis based on a standard addition method and direct detection method showed high precision for measuring glucose at SiO₂(LuPc₂)PANI(PVIA)-CNB/GOx biosensor. The SiO₂(LuPc₂)PANI(PVIA)-CNB/GOx biosensor stored under refrigerated condition over a period of 45 days retains ~ 96.4% glucose response current.