Preparation of Supramolecular λ-Deoxyribose Nucleic Acid and, Multi-Walled Carbon Nanotube Bioconjugate (λ-DNA-MW-CNT) Towards Prototype Biosensor Development

We report Multi Walled Carbon Nanotubes (MW-CNTs) functionalization and, Deoxyribose Nucleic Acid (DNA) conjugate preparation (MW-CNT-DNA) by a simple process. The mixed chirality, multi-walled carbon nanotubes were dispersed in 1% (v/v) aqueous Triton-X and, chemically functionalized through nitric acid (HNO₃) oxidation giving carboxyl group (–CO₂ H) generation on MWCNTs caps area in the aqueous media. The dispersion and, functionalizations were confirmed, respectively, through Atomic Force Microscopy (AFM) and, Fourier Transform Infra Red (FT-IR) absorption spectroscopy observations for carboxyl groups presence in the functionalized samples of MW-CNTs. The λ-DNA fragment's attachment reaction to the functionalized MW-CNTs cap regions over a 24 hours time-period at 4 °C furnished MW-CNT-λ-DNA bioconjugate which were confirmed by electrophoretic movement observations of the bioconjugate product's sample. It is the first report of chemical conjugation of supramolecular biological material, i.e., λ-DNA consisting of 48, 502 base pairs, to the carboxyl (–CO₂H) functionalized MW-CNTs. The bioconjugate was found to be stable and, robust during preparation and, processing. The conjugated product could be used in designing prototypical DNA based biosensor for engagement in chemo-biological sensing and, as biomolecular transporter for various kinds of pay-load delivery purposes.