Electrochemically Activated Conductive Ni-Based MOFs for Non-enzymatic Sensors Toward Long-Term Glucose Monitoring

Electronic Chemical Sensors Based on Conductive Framework Materials

The development of portable electronic chemical sensors is key to solving a number of challenges, including monitoring environmental and industrial hazards, as well as understanding and improving human health. Framework materials possess several desirable characteristics that make them well-suited for electroanalytical applications, including high surface area, atomically precise distribution of active sites, and tunable properties that can be leveraged through modular reticular chemistry. This review highlights the emergence of conductive framework materials as active components in electrically transduced chemical sensors, including the development of new materials for the detection of a wide variety of analytes in both gas and liquid phase. The efforts to gain fundamental understanding of the molecular interactions and sensing mechanisms between framework materials and analytes are described, along with applications of these materials on portable and flexible substrates. The review suggests areas for further study, including the study of material-analyte interactions at the molecular level and the continued development of scalable methods for the integration of framework materials into low-power, portable sensing devices.

Trends in conductive MOFs for sensing: A review

Metal-organic frameworks (MOFs) are porous, ordered arrays formed by coordination bonds between organic ligands and metal ions or clusters. The highly tunable properties of the MOF structure and performance make it possible to meet the needs of many applications. Conductive MOFs are essential in the domain of sensing due to their electrical conductivity, porosity, and catalytic properties, offering an effective platform for detection. Numerous sensing devices that utilize conductive MOFs have been created. This text presents a thorough overview of the diverse applications of conductive MOFs within the sensing field. The results of this work provide insights into the properties and synthesis methods of conductive MOFs and the working mechanisms of sensors based on conductive MOFs, which will help to deepen the study of such materials, provide a new vision for the design and production of novel functional materials, and promote the development and application of sensors based on conductive MOFs.

Recent Progress in MOF-Based Electrochemical Sensors for Non-Enzymatic Glucose Detection

In recent years, substantial advancements have been made in the development of enzyme-free glucose sensors utilizing pristine metal-organic frameworks (MOFs) and their combinations. This paper provides a comprehensive exploration of various MOF-based glucose sensors, encompassing monometallic MOF sensors as well as multi-metal MOF combinations. These approaches demonstrate improved glucose detection capabilities, facilitated by the augmented surface area and availability of active sites within the MOF structures. Furthermore, the paper delves into the application of MOF complexes and derivatives in enzyme-free glucose sensing. Derivatives incorporating carbon or metal components, such as carbon cloth synthesis, rGO-MOF composites, and core-shell structures incorporating noble metals, exhibit enhanced electrochemical performance. Additionally, the integration of MOFs with foams or biomolecules, such as porphyrins, enhances the electrocatalytic properties for glucose detection. Finally, this paper concludes with an outlook on the future development prospects of enzyme-free glucose MOF sensors.

A portable ascorbic acid in sweat analysis system based on highly crystalline conductive nickel-based metal-organic framework (Ni-MOF)

Conductive metal-organic frameworks can provide unique porous structures, large pore volumes, many catalytically active sites and high crystallinity, and so are becoming increasingly important and attractive as electrocatalytic materials. The present work synthesized nanorods of the conductive compound Ni₃(2,3,6,7,10,11-hexaiminotriphenylene)₂ (Ni₃(HITP)₂) with a high degree of crystallinity from HITP ligands and Ni²⁺ ions. Screen-printed electrodes made with this material were employed to fabricate an enzyme-free sensor for the detection of ascorbic acid (AA). The sensor exhibited good catalytic activity during the electrocatalytic analysis of AA in alkaline media, attributed to the synergistic effect of highly active Ni-N₄ catalytic sites in the nanorods, the two-dimensional superimposed honeycomb lattice of the Ni₃(HITP)₂, and the large specific surface area of this material. The latter property facilitated efficient electron transfer during catalytic oxidation. A portable electrochemical AA detection system was developed using Ni₃(HITP)₂ as the electrode material together with application-specific integrated circuits and a smartphone application with App. Good sensing performance was obtained, including a wide linear range (2-200 μM) with high sensitivity (0.814 μA μM^-1 cm^-2), and low detection limit (1 μM). This system can be used to monitor AA levels and trends in sweat to assess vitamin C intake as a part of personal health management.