Amperometric and photometric responses of in situ coupled glucose oxidase-poly (propylene imine) dendrimer based glucose biosensor

In this work, poly (propylene imine) dendrimer (PPI) was coupled to glucose oxidase enzyme (GOx) in situ and used as a bioreceptor in a glucose biosensor. The coupling was accomplished by the use of 1-ethyl-3-(dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) linker. Ultraviolet visible spectroscopy, Fourier transform infra red spectroscopy and scanning electron microscopy were used to confirm the coupling reaction. A biosensor was then prepared by drop coating the GOx-PPI onto a glassy carbon electrode and then used for the amperometric detection of glucose. The bio-recognition of glucose by the GOx-PPI was observed with a detection limit of 0.1 mM. Photometric responses showed good enzyme stability and activity with a Michaelis-Menten constant of 0.127 mM.