Nonenzymatic electrochemiluminescence glucose sensor based on quenching effect on luminol using attapulgite–TiO2

A new nonenzymatic glucose ECL sensor based on attapulgite (Att) integrated with semiconductor material TiO2 was developed. The prepared material was characterized by transmission electron microscopy (TEM), X-ray diffractometer (XRD), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Based on ECL experimental results, Att–TiO2 composites were found to be able to improve the ECL properties of luminol. When glucose is added into the system, TiO2 NPs serve as a catalyst and dissolved O2 acts as a cosubstrate for the glucose oxidation reaction. Dissolved O2 also worked as coreactant for the luminol ECL emission. Due to the consumption of dissolved O2, a quenching effect would appear on the luminol ECL emission. Under the optimized conditions, the linear logarithmic relationship between ECL intensity and the concentration of glucose was valid in the range from 1.0 mM to 1.0 nM (R = 0.9976) with a detection limit (S/N = 3) of 10.0 pM. In addition, the proposed sensor presented good reproducibility, stability, and sensitivity for glucose detection and can be successfully applied in the determination of glucose in real blood samples.