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Dopamine biosensor based on surface functionalized nanostructured nickel oxide platform

Roychoudhury, Appan, Basu, Suddhasatwa, Jha, Sandeep Kumar
Biosensors & bioelectronics 2016 v.84 pp. 72-81
Fourier transform infrared spectroscopy, X-ray diffraction, anionic surfactants, atomic force microscopy, biosensors, detection limit, dopamine, electrochemistry, electrodes, indium tin oxide, light scattering, nanoparticles, nickel, polyethylene terephthalates, shelf life, sodium dodecyl sulfate, sol-gel processing, transmission electron microscopy
A dopamine biosensor has been developed using nickel oxide nanoparticles (NPs) and tyrosinase enzyme conjugate. Nickel oxide (NiO) NPs were synthesized by sol–gel method using anionic surfactant, sodium dodecyl sulphate (SDS), as template to control the size of synthesized nanoparticles. The structural and morphological studies of the prepared NPs were carried out using X-ray diffraction (XRD), transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques. Afterwards, tyrosinase enzyme molecules were adsorbed on NiO NPs surface and enzyme coated NPs were deposited on indium tin oxide (ITO) coated flexible polyethylene terephthalate (PET) substrate by solution casting method. The formation of enzyme–NPs conjugate was investigated by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) techniques and used in selective detection and estimation of neurochemical dopamine by electrochemical method. The fabricated Tyrosinase/NiO/ITO electrode exhibits high sensitivity of 60.2nA/µM in linear detection range (2–100μM) with a detection limit of 1.038μM. The proposed sensor had a response time of 45s, long shelf life (45 days) with good reproducibility and selectivity in presence of interfering substances and was validated with real samples. The tyrosinase enzyme functionalized NiO platform has good bio-sensing efficacy and can be used in detection of other catecholamines and phenolic neurochemicals.