An implementation of functionalized carbon nanotubes on optical biosensors

Official URL: http://192.168.1.20/record=b1293748 (Table of Contents)

Carbon Nanotubes have attracted great attention since their discovery with their uniqueness based on outstanding mechanical, electronic and structural properties they have and wide application potential they promise. The significant properties of carbon nanotubes accumulated the studies on CNT-based electro analytical sensor applications. Although there is a huge amount of work on implementing CNTs for electrochemical studies, their implementation in optical biosensor platforms remains to be discovered. Therefore, this study focuses on the Multi-Walled Carbon Nanotube implementation for optical biosensor platforms. The MWNTs were firstly functionalized via a two-step process of diimide-activated amidation and both the functionalized MWNTs and the protein immobilization on them were characterized with Dynamic Light Scattering, Fourier Transform Infrared Spectrometry and Scanning Electron Microscopy analysis. In order to explore the sensitivity enhancement that carbon nanotubes promise for immunosensor and oligonucleotide-sensor applications, microarray experiments in which functionalized MWNTs were used as a new microarray substrate were performed. MWNT coated slides enhanced the signal intensities of constructed platforms approximately 2 folds when antibodies were used as probe biomolecules with a lowest detection limit of 1,9 ng/ml. The signal enhancement served by the MWNT coted surfaces was 3 folds when oligonucleotides were used as probe biomolecules with a lowest detection limit of 1 nM. Also this MWNT coated slides and protein immobilization on them were further characterized via Scanning Electron Microscopy and Atomic Force Microscopy analysis. The performed microarray experiments together with the other characterization studies, suggest functionalized MWNTs as good candidates for optical sensor platforms combining the benefits of increased surface area of 3D carbon nanotube structures, high binding capacity of MWNTs for biomolecules without changing their biologically active conformation, and the generation of a high signal to noise ratio according to the excellent low auto fluorescence of MWNTs.