Nowadays diabetes comes out as one of the most common diseases. It is estimated that over 400 million people suffer from this illness. Therefore, scientists are bound to find a solution and create a glucose sensor, which will be sensitive, selective, stable as well as easy to produce.
Here, we propose the nanoscale Au-Ti heterostructure functionalized with glucose oxidase specific towards glucose presence. The fabrication of the electrode was realized by anodization of Ti foil and chemical etching resulted in the ordered Ti nanodimples (TiND). Next, gold nanoparticles (AuLr) were prepared by thin Au layer sputtering followed by laser dewetting. Last but not least, the enzyme immobilization via entrapment into the chitosan matrix was performed.
The morphology of Ti nanodimples and Au nanoparticles was investigated by scanning electron microscopy and it is proven that nanoparticle size does not exceed the cavities dimensions. Fourier transformation infrared analysis was utilized to confirm the presence of glucose oxidase and chitosan. Experiments aimed at determining sensor parameters were conducted in 0.1 M PBS with glucose addition. The sensitivity factors of 23.67 and 10.05 µAcm-2mM-1 were determined and correspond to following linear ranges of 0.04 – 15.05 and 15.05 – 40.00 mM. The limit of detection equals only 1.77 µM. The selectivity of prepared electrode material was verified using NaCl, ascorbic acid, fructose, glycine, dopamine, acetylsalicylic acid, uric acid, and acetaminophen. No interference is observed and in addition the material is stable over multicyclic measurements. Moreover, validation in real samples such as human serum, sweat and saliva confirmed the potential application of the sensor for glucose monitoring in physiological fluids.
This work was financed by National Center for Research and Development under grant no LIDER/2/0003/L-8/16/NCBR/2017.