Synergistic pNiPc-COF/GO hetero-structures for ultrasensitive non-enzymatic glucose electrochemical sensing

This study synthesized a novel pNiPc-COF via low-temperature molten salt method and composited it with GO. The synergy between them overcomes the conductivity bottleneck of pure COFs. • The electrochemical sensor based on this composite shows exceptional glucose detection performance, with a sensitivity of 875.71 μA·mM −1 ·cm −2 and a detection limit of 0.103 μM. • The sensor shows over 90% selectivity for glucose amid common interferents, along with excellent long-term stability and high repeatability. • The sensor's linear range is 0.15–9.45 mM, covering the physiological glucose window (3–6 mM) and extending to higher concentrations. Glucose electrochemical sensors underpin clinical diagnosis, biomanufacturing, food quality control and environmental surveillance. Covalent organic frameworks (COFs) are attractive for electroanalysis, yet nearly all COF glucose sensors require glucose oxidase immobilization, limiting long-term stability and scalability. Herein, we fabricate an enzyme-free glucose electrocatalyst: nickel phthalocyanine COF (pNiPc-COF) hybridized with graphene oxide (GO) via one-pot solvothermal treatment. XRD, SEM, FTIR, TGA and XPS confirm uniform pNiPc-COF/GO heterostructures; electroanalytical tests reveal strong synergistic glucose oxidation from dense Ni catalytic sites and fast charge transport in GO. At +0.65 V vs. SCE, the sensor achieves 5 s response over 0.15–9.45 mM glucose, with sensitivity of 875.71 μA mM −1  cm −2 and LOD = 0.103 μM (S/N = 3). It also exhibits strong anti-interference capability, offering a stable, high-performance enzyme-free platform for clinical glucose quantification. Download: Download high-res image (114KB) Download: Download full-size image