Flower-like CoO nanowire-decorated Ni foam: A non-invasive electrochemical biosensor for glucose detection in human saliva

Diabetes is a prevalent disease that necessitates invasive and uncomfortable methods for monitoring glucose levels, posing the risk of infection. Consequently, there is an urgent need for non-invasive glucose biosensors to aid in diabetes diagnosis and management. This study presents a novel non-invasive electrochemical biosensor capable of detecting glucose concentration in human saliva. The biosensor utilizes a nickel foam substrate adorned with needle-like CoO nanowires, which offer an ideal surface area for nanowire growth. These nanowires exhibit a self-assembled flower-like nanostructure with a highly porous configuration, presenting an exceptional BET surface area of 154.3 m² g⁻¹ and displaying excellent catalytic performance. The combination of the substrate, nanowires, and nanostructures results in remarkable sensitivity (28.22 mA mM⁻¹ cm⁻²), a low detection limit (0.55 μM), a wide sensing range (0.005-2.525 mM), and satisfactory stability and reproductivity. Experimental results demonstrate a remarkable recovery rate (100.1 %) for glucose detection in real human saliva samples, highlighting the potential of this biosensor for real-time and non-invasive glucose monitoring. This work holds promising implications for the future management of diabetes and the healthcare system dedicated to diabetes patients.