Non-enzymatic amperometric glucose sensing by novel Cu-MOF synthesized at room temperature

Abstract

Cu-metal–organic framework (Cu-MOF) derived from 1,2,4,5-benzene tetracarboxylic acid (H₄BTC) has been synthesized through a quick and soft-template synthesis at room temperature. XRD, FT-IR, BET, SEM-EDX, and Raman spectroscopy were used for the morphological and microstructural characterization. The as prepared Cu-MOF was drop-cast onto a screen-printed carbon electrode (SPCE) for developing a sensitive enzyme-free electrochemical glucose platform. The electrochemical behaviour was investigated by cyclic voltammetry and amperometric tests, highlighting the good electrochemical sensing properties towards glucose detection. A remarkable enhancement was obtained combining Cu-MOF with chitosan (Cs). The Cs/Cu-MOF/SPCE sensor displayed a high sensitivity of 1378.11 μA cm⁻² mM⁻¹ and a low detection limit of 2 μM (3σ/s) in a linear dynamic range (R² = 0.992) from 2 μM to 1700 μM. The practical applicability of the Cs/Cu-MOF/SPCE sensor was evaluated by detecting glucose in spiked saliva samples resulting in a high recovery percentage (ranging from 95.4% to 108.7%). These results, along with the quick and simple synthesis of Cu-MOFs at room temperature, open new routes for developing efficient enzyme-free glucose sensors.