Sensitive non-invasive electrochemical sensing of glucose in saliva using amorphous SnOx decorated one-dimensional CuO nanorods rich in oxygen vacancy defects

The non-enzymatic glucose sensor with high sensitivity is significant for non-invasive glucose continuous monitoring in saliva. Herein, the composite with amorphous SnOx decorated one-dimensional CuO nanorods were prepared via the hydrothermal and sintering procedure. The sensitivity of sensor is 2303 mu A mM-1 cm-2, and the detection range of sensor is 1 mu M to 6000 mu M. For interferences such as dopamine, lactic acid, ascorbic acid, and sodium chloride, the sensor has good selectivity. TPD confirmed that this composite with amorphous SnOx decorated CuO nanorods has oxygen vacancy defects. This enhanced performance should be attributed to the addition of amorphous SnOx, which induces more oxygen vacancy defects. This sensor with good electrochemical performance may be used for continuous detection of saliva with low glucose content. The sensor constructed by CuO-SnOx composite could detect the changes of glucose content in saliva before and after meals. Measuring glucose in saliva samples at different time intervals confirmed that it was closely related to the blood glucose level measured with a commercially available blood glucose meter. Oxygen-enriched vacancy defects induced by structure can improve the performance of sensors, which may provide some new ideas for the synthesis of high-performance sensor composite.

Automated summary

A non-enzymatic glucose sensor with high sensitivity and good selectivity was developed using CuO-SnOx composite material. This sensor can continuously monitor glucose content in saliva and is closely related to blood glucose levels measured by a commercial blood glucose meter.