Oxygen vacancies enriched multi-channel-like metal-doped Co₃O₄ nanosheets by Lewis acid etching for detection of small biological molecules in apple juice and wine

Excessive small biological molecules such as Cd(II), Pb(II) and glucose in food pose a non-negligible threat to its inherent quality and human health, which makes it imperative to develop the highly sensitive sensor for Cd(II), Pb(II) and glucose detection. Metal cation-doped Co₃O₄ modified electrode materials have attracted vital interest in the electrochemical detection of Cd(II), Pb(II) and glucose because of their synergetic effect on Cu/Co and oxygen vacancies. Herein, a simple morphology and defect modulation strategy is proposed to synthesize multi-channel-like M-doped Co₃O₄ nanosheets (M = Cu, Mn, Fe, Ni, and Zn) via the Lewis acid etching process. The Cu/Co interaction and oxygen vacancies of Cu-Co₃O₄ multichannel nanosheets play an important role in the simultaneous detection of small biological molecules. The Cu-Co₃O₄ multichannel nanosheets exhibit the sensitivity of 20.59 µA µM⁻¹ for Pb(II), 8.73 µA µM⁻¹ for Cd(II) as well as 1613.86 µA mM⁻¹ cm⁻² for glucose, which is successfully applied in food applications such as apple juice and wine and maintain excellent stability and anti-interference. This design not only successfully constructs oxygen vacancies enriched M-Co₃O₄ multichannel nanosheets, but also demonstrates the application potential of electrochemical sensors in food safety.