Significant influence of controllable surface oxygen vacancies of CuO for enhancing sensitivity of glucose detection

Oxygen vacancies enriched CuO nanoflakes was reported to accelerate the adsorbed hydroxyl ions to promote the formation of Cu 3+ species, which reduce the one-potential and facilitate the glucose oxidation. • CuO nanoflakes with abundant surface oxygen vacancies was simply synthesized. • High-angle annular dark-field image, X-ray photoelectron spectroscopy, and electron spin resonance were employed to prove the existence of enriched oxygen vacancies. • Oxygen vacancies improve the adsorption and stabilization of OH – to in favor of the formation of Cu 3+ species, which reduces the onset-potential and facilitates the glucose oxidation. • lower onset-potential of +0.22 V, ultrahigh sensitivity of 4870 μA mM −1 cm −2 , higher selectivity, fast response time with about 2s were obtained as glucose sensor. The construction of oxygen vacancies, as one of defects engineering, is a promising strategy to boost the electrocatalytic activity. Herein, CuO nanoflakes enriched with oxygen vacancies were successfully synthesised via a simple one-pot method with stirring. High-angle annular dark-field scanning, X-ray photoelectron spectroscopy and electron spin resonance spectroscopy were performed to confirm the existence of enriched oxygen vacancies. The as-synthesised CuO nanoflakes enriched with oxygen vacancies and exhibited an excellent performance for glucose detection with a lower onset-potential of +0.22 V, ultrahigh sensitivity of 4870 μA mM −1 cm −2 and low detection limit of 0.5 μM. The superior performance of the CuO nanoflakes may be attributed to surface oxygen vacancies, which accelerate the adsorbed hydroxyl ions to promote the formation of Cu 3+ species, thereby, reducing the one-potential and facilitating the glucose oxidation. This work would serve the guide for the rational design of other efficient catalysts for glucose detection via constructing oxygen vacancies.