MOF-71 SYNTHESIS AS ACTIVE MATERIAL NONENZYMATIC ELECTROCHEMICAL SENSOR FOR URIC ACID DETECTION IN HUMAN BODY

• Main Author: Nur Hakim, Fahmi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/41865
• Institution: Institut Teknologi Bandung

The uric acid level in the human body that exceeds the normal limit (0.24-0.42 mM) leads to many diseases such as hyperuricemia, gout, and arthritis. So, measuring uric acid levels is needed regularly to maintain a normal level of uric acid. There are several methods of uric acid measurement such as colorimetric, enzymatic, and electrochemical. Electrochemical methods have been developed to replace colorimetric methods that have poor stability and enzymatic methods that depend on the quality of the enzyme. The electrochemical method was chosen because it measures uric acid with high accuracy with low production costs. Nowadays, the material that has been developed as a chemical sensor is Metal-Organic Framework (MOF). MOF has been developed as a sensor due to its large pore volume, high surface area, chemical tenability, and excellent thermal conductivity. MOF is a hybrid material with a metal core coordinating with organic ligands. Cobalt-based MOF (MOF-71) has been recently developed as a sensor. Cobalt (Co) metal is the core of MOF-71 which binds to terephthalic acid (H2BDC) as ligand and N,N-dimethylformamide (DMF) to build a certain framework. MOF-71 synthesis was carried out by the solvothermal method. This method was chosen because it produced MOF with a high surface area, fairly easy processing, and low production costs. Characterization of MOF-71 was carried out by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy, and Brunauer-Emmet-Teller (BET) Surface Area Analyzer. The results showed that MOF-71 had a crystal size of 0.981 nm, a particle size of 78.25 ?m and a surface area of 56.542 m2 g-1. The sensing performance of the MOF-71 for sensor was carried out by Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) test in PBS solutions with pH 7.4. The CV test results showed that the current density of the oxidation reaction is linear to the increase of uric acid concentration and scan rate. DPV test showed that the sensitivity of MOF-71 is 0.4811 mA mM-1 cm-2, the detection limit is 15.610 ?M, and the quantification limit is 52.040 ?M with an average measurement error of 7.663%. MOF-71 has good selectivity in recognizing uric acid when compared to other compounds found in blood serum such as glucose and urea. In stability testing, MOF-71 stored at refrigerator temperature had better stability compared to MOF-71 which was stored at room temperature. Therefore, MOF-71 is a promising material for the electrochemical sensor, especially a uric acid sensor.