Nano-Structured CuO Grown with Aqueous NH3 for Salivary Glucose Detection

CuO nanostructures grown on flexible Cu foil by a simple chemical bath deposition in a solution of aqueous ammonia have been explored for non-invasive and non-enzymatic detection of salivary glucose. The nanostructured electrode developed with 100 µL of aqueous ammonia achieves a high sensitivity of 3243 µA mM-1 cm-2, linear range up to 3 mM, and limit of detection of 0.77 µM. The electrode also demonstrates good anti-interference properties, high reproducibility, repeatability, and long-term stability up to 30 days. In addition, the electrode exhibits remarkable sensitivity of 2865 µA mM-1 cm-2 for salivary glucose detection. To explore its potential for non-invasive detection of actual salivary glucose, pre-prandial and post-prandial salivary glucose of different human volunteers were measured using the electrode and were found to be correlated with corresponding blood glucose levels. Development and investigation of similar sensors for non-invasive detection via untraditional methods would certainly pave the way towards next generation glucose monitoring devices and systems.