MODIFICATION CUBTC WITH CNT USING DIRECT MIXING METHOD FOR GLUCOSE SENSOR APPLICATION

• Main Author: MUSTAQIM (NIM: 23315308), AMRINA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25462
• Institution: Institut Teknologi Bandung

<p align="justify"> <br /> <br /> Nowadays, diabetes mellitus is one the most serious health problems and one of the highest causes of death in the world. This disease is mainly caused by the high concentration of glucose in the human’s blood. Thus, controlling glucose level in the blood is needed. Glucose control can be done in two ways: invasive and non-invasive methods. Non-invasive methods are preferred because they do not need any surgery. This method usually uses a glucose sensor. Materials used to detect glucose usually employs noble metals, e.g., Ag, Au, and Pt, which are high cost and invective for industry application. In this work, CuBTC was selected as a glucose sensor materials due to its feasible fabrication process and low cost. <br /> <br /> However, CuBTC itself has a low electronic conductivity so that it is not effective to oxidize glucose. Therefore, CuBTC needs to be modified using conductive materials, e.g., carbon nanotubes (CNT) to improve its performance. The modification of CuBTC using CNT was performed on different composition of CuBTC and CNT equals to 1:0; 1:0.25 (CC1); and 1:1.25 (CC2) by direct mixing method. <br /> <br /> The samples were then characterized using X-Ray Diffraction (XRD) to determine their crystalline structure, Scanning Electron Microscopy (SEM) to study its morphology, and Fourier Transform Infrared (FT-IR) to determine its transmittance spectrum. The XRD test results show that the synthesized material has the diffraction peaks corresponding to the diffraction peaks of CuBTC from the reference. The addition of CNT increases the diffraction peaks intensity of CuBTC. SEM images show that the synthesized CuBTC has octahedral morphology with a length of 200-350 nm. In CNT-modified CuBTC, the CNT penetrates the octahedral structure of CuBTC. The SEM analyses also show that the diameter of CNT particles is 50-60 nm. The FTIR characterization reveals that the addition of CNT hinders the transmittance spectrum of CuBTC. The addition also reduces the transmittance peak of Cu-O bonding at a wavenumber of around 700-800 cm-1. <br /> <br /> To investigate the sensitivity of the materials toward the glucose, a sensor test was performed using a non-enzyme method. In this research, the test was done by an electrochemical method using cyclic voltammetry technique. The potential and scanning rate was set to 0-0.8 V and 50 mV/s. Sensitivity was measured using 5mM glucose. The anodic peak was observed at potential and current of 0.7 V and 1 mA/mg for pure CuBTC sample, 0.6 V and 1.3 mA/mg for CC1 sample, and 0.55 V and 1.5 mA/mg for CC2 sample. The addition of CNT reduces the required voltage to reach the anodic peak but increases the resulting peak current. The concentration of glucose was varied to study the effect on the sensitivity of CC2 sample (which exhibits the best performances). The measurements were conducted using ampere metric technique and the results show that the sensitivity of CC2 sample toward glucose is 795.3 MA.MM-1.cm-2 with a detection limit of MM. <br /> <p align="justify">