Faculty of Engineering and Information Technologies, School of Chemical and Biomolecular Engineering
Abstract
The aim of this study is to design and develop novel carbon nanotube and graphene based platforms as biosensors for electrochemically detecting dopamine. The use of such novel nanostructure, which was introduced with functional groups or bio-recognizition molecular, will enable the development of affinity-based biosensors for disease diagnostics and therapy monitoring. The electrical devices are extremely useful for dopamine determination in a fast and simple way. In this study, a Nafion/MWCNT chip prepared by inkjet printing was developed for rapid dopamine determination in human serum. A well dispersed Nafion/MWCNT composite was investigated with homogeneous double layers which increased the efficiency of dopamine detection, producing a measurable current change at the underlying sensor electrode. This platform as described successfully demonstrated detection of dopamine concentrations (0.1 M to 10 M, R=0.999) using DPV and amperometry methods. This direct measurement of dopamine in serum samples without pretreatment and dilution is reported for the first time in a Nafion/MWCNT system. In addition, to improve the specificity of the detecting probe, the direct electrochemical detection of antibody-antigen recognition was developed. Graphene can be used as an electrode surface for sensitive detection of a label. Graphene sheets were modified with gold nanoparticles or the dopamine antibody fragments (Fab’) loaded with sulphur binding with gold. Unfortunately, such bio-sensing systems did not perform sensitively and selectively for detection of the neurotransmitters/neurochemicals by utilizing certain nanostructure and introducing various functional groups. Further study will be conducted on analysing fragments’ and the whole antibodies’ activity and affinity of specific recognition
