چكيده به لاتين
In this thesis, we introduce a novel non-enzymatic glucose sensor based on interdigitated vertically aligned carbon nanotube arrays (VCNTs). The CNTs are fabricated using plasma-enhanced chemical vapor deposition (PECVD) method, by employing Ni as growth catalysts. Unlike usual electrochemical sensors, which require a three-electrode potentiostat setup to operate, by bringing the working electrode and the counter electrode together in an interdigitated electrode (where the distance between the two electrodes are set to 12 microns), and eliminating the reference electrode, the fabricated sensor in this study yields high sensitivity to different glucose concentrations. Furthermore, instead of employing a concentrated electrolyte solution as the test medium, which is usually used in electrochemical experiments with a potentiostat, the fabricated sensor shows clear sensitivity to glucose concentrations in distilled water. By using distilled water as opposed to a concentrated electrolyte solution typically used in electrochemical three-electrode potentiostat setups, we ensure that the sensor itself will not be greatly oxidized during tests and that the results are reproducible. Although DC measurements showed selective sensitivity to glucose, easily oxidizable ascorbic acid (which usually coexist with glucose in blood) was seen to interfere with measurements by producing comparable currents to glucose. However, AC impedance tests showed very clear selectivity between the two substances. Amperometric tests were then repeated by using an AC modulated DC voltage, which completely removed the response of the otherwise interfering ascorbic acid.
