Highly Efficient Enzyme-Free Glutamate Sensors Using Porous Network Metal–Organic Framework-Ni-NiO-Ni-Carbon Nanocomposites

This study introduces an innovative electrochemical sensor designed to detect glutamate using a nonenzymatic approach. The sensor utilizes a porous network metal-organic framework (Ni-MOF)-NiO-Ni-Carbon nanocomposite (PNM-NiO-Ni-Carbon) as an electrode modifier, which was synthesized and assessed for its effectiveness. Cyclic voltammetry measurements demonstrated that the PNM-NiO-Ni-Carbon nanocomposite, synthesized at 450 °C, displayed remarkable electrocatalytic activity for glutamate oxidation. The linear range for detection spanned from 5 to 960 μmol/L, and the sensor achieved a low detection limit of 320 nmol/L (S/N = 3), which was comparable to previously reported data. Moreover, the sensor exhibited high accuracy and favorable recovery rates when tested with real samples, thus, demonstrating its potential for rapid glutamate detection. The real samples were analyzed using both electrochemical and high-performance liquid chromatography methods, and the results obtained from the two methods did not differ significantly, validating the sensor's excellent practical performance. Based on our findings, the PNM-NiO-Ni-Carbon system exhibits potential for a wide range of biomedical applications.