CVD Fabrication of CNTs/Ag Electrochemical sensor for Pharmaceutical Analyses Using Sequential Injection Analysis

The proposed work aims to fabricate a robust and durable electrode through the catalytic chemical vapor deposition (CVD). Carbon nanotubes (CNTs) will be synthesized on the surface of silver metal in a CVD reactor by the decomposition of ethylene gas in the presence of hydrogen gas at high temperature (800C). The synthesis of the CNTs is catalyzed by ferrocene. The advantage of the CNTs modified electrode fabricated in this way over other CNTs electrodes is the strong adhesion of the CNTs layer to the substrate. This result leads to a direct electrical connection between the CNTs layer and Ag substrate, which in turn leads to rapid heterogeneous electron transfer and hence enhanced sensing performance. CNTs/Ag electrode will be characterized initially by Scanning Electron microscopy, and further by Raman and transition Electron Microscopy. Moreover, X-ray Photoelectron spectroscopy will be employed for the depth profiling of the CNTs layer. The fabricated electrode will then be utilized as a differential electrolytic potentiometric sensor in a sequential injection analysis (SIA) system for the determination of ascorbic acid and ciprofloxacin. Parameters such as flow rate, polarizing current density, mark-to-space ratio of the square wave, and reagent concentrations will be optimized.