Topic of Research Seminar: Development of Metal-Organic Frameworks (MOFs) based electrochemical sensors for the detection of glucose
Abstract: Electrochemical detection methods are highly attractive for the monitoring of glucose, cancer, infectious diseases, and biological warfare agents due to their low cost, high sensitivity, and functionality despite sample turbidity, low power requirements, and relatively simple control infrastructure. The development of electrochemical biosensors is laden with great challenges, which include sensitivity, selectivity stability and reproducibility. As a new kind of crystalline molecular material, MOFs are emerging as a very effective tool for electrochemical sensing applications because of the excellent advantages such as ultrahigh porosity, large surface areas, large pore volume, tunable structure, thermal and chemical stability, and chemical functionality. Incorporating heterogeneous nanostructured materials in MOFs promotes the development of applications for MOF-based materials in electrochemical sensing. The potential of the MOFs composites has also been realized as ideal hosts for functional materials (like conducting nanoparticles). These composites are thus demonstrated to have superior electrocatalytic/electrochemical sensing properties than their pristine forms. Accordingly, various MOF composite-based platforms have been developed as efficient electrochemical sensors for environmental and biochemical targets. Thus, the central theme of this dissertation pertains to highlighting the critical roles that MOFs play and their nanocomposites when applied in the development of electrochemical biosensors.
The development of non-enzymatic glucose e1ectrochemical sensors based on Ag@TiO2@ZIF-67 and MOF-derived Ag@In2O3 is described in this thesis. The aim was to develop electrochemical biosensors that specifically detect Glucose over a wide concentration range, with high sensitivity and low detection limits. The electrode surface was modified by Nanocomposites, i.e., Ag@TiO2@ZIF-67 on GCE and MOF-derived Ag@In2O3 on Nickel Foam. A range of e1ectrochemical techniques was employed in this research. The as-synthesized electrodes were analyzed by X-ray diffraction at 2θ values using Cu-Kα radiation for structural analysis. Scanning electron microscopy was used to investigate the morphology of the electrode materials. The electrochemical measurements were studied by a Gamry potentiostat at ambient conditions. For the three-electrode configuration, synthesized materials on GCE and Nickel Foam were employed directly as working electrodes, and a platinum wire and Ag/AgCl were employed as counter and reference electrodes, respectively.
It was determined that the oxidation of Glucose was a diffusion-controlled process. The reaction was electrochemically reversible, involving the spontaneous adsorption of Glucose on the electrode surface. The Ag@TiO2@ZIF-67 on GCE and MOF-derived Ag@In2O3 on Nickel Foam sensors were efficiently used to determine Glucose in aqueous solutions. The non-enzymatic electrochemical sensors were highly selective toward Glucose in the presence of other biological interfering agents. The lowest Glucose detection limit was achieved 0.99 µM from Ag@TiO2@ZIF-67 and 0.49 µM from MOF-derived Ag@In2O3.
Nevertheless, both the Ag@TiO2@ZIF-67 on GCE and MOF-derived Ag@In2O3 on Nickel Foam sensors were suitable for monitoring Glucose at concentration levels typical for human blood serum. In summary, the electrochemical biosensors proposed in my Ph.D. study exhibited high sensitivity and selectivity for the Glucose analyte in the presence of common interference species. Our results have shown that the performance of the electrochemical biosensors is significantly dependent on the enhanced catalytic and conductive properties of MOFs incorporated with nanostructured materials. The unique nanomaterials-based platforms proposed in this dissertation open the door to the design and fabrication of high-performance electrochemical biosensors for medical diagnostics.
Subject Field of Topic: Electrochemical Sensing
Name of Speaker: Dooa Arif
Professorial Rank of Speaker: Ph.D. Researcher
University Email of Speaker: [email protected]
Affiliation of Speaker: NUST School of Chemical and Materials Engineering (NUST-SCME)
Date and Venue: January 31, 2023 at 1400 hrs, Seminar Hall, School of Chemical and Materials Engineering (SCME), NUST Islamabad Campus