Ligand-to-metal charge transfer (LMCT) complex: New approach to non-enzymatic glucose sensors based on TiO2

Titanium metal covered with titanium dioxide (Ti/TiO2) was used as a promising non-enzymatic glucose sensor demonstrating a new approach to electrochemical glucose determination. A Ti/TiO2 nanotubes-glucose complex formation on an electrode surface was demonstrated by infrared, Raman, and X-ray photoelectron spectroscopy. The main electrochemical method used for glucose detection was electrochemical impedance spectroscopy as a promising method for an easy electrochemical determination. To the best of our knowledge, this kind of sensor has never been studied especially in case of non-enzymatic glucose detection. Ti/TiO2 glucose sensor displays a wide practical linear range (1–15 mM) in a pH neutral condition, which cover the typical range in diabetic patients. The selectivity and the limit of detection were 8.3 kΩ·mM−1 and 1.2 mM, respectively. Therefore this kind of a system is very promising candidate for blood glucose sensing which should be able to replace enzymatic glucose sensors. Based on the properties of the prepared sensors, TiO2 is an unrivalled material for glucose sensing comparable with the enzymatic sensors.