Dyes Encapsulated By Single Walled Carbon Nanotubes: A Raman Nanoprobe of Cancer Detection

Abstract

Carbon nanotubes are among the most promising platforms for biological applications such as cancer targeting, medical imaging and drug delivery. Herein we present a novel approach to modify single-walled carbon nanotubes (SWCNTs) into Raman nanoprobes capable of targeting biomarkers on cancer cells. The process involves cleaning and shortening in acids followed by encapsulation of specific organic dyes. Subsequently the as-synthesized Raman nanoprobes are then covalently attached with modified NH2-PEG-COOH to make a generic nanoprobe that is bio-compatible and highly dispersed in aqueous or buffer media. When covalently linked to specific antibodies anti-E-cadherin (monoclonal mouse anti-human) and CK19 (cytokeratin), such nanoprobes can be used to detect there bio-markers in the membrane of breast cancer cell lines.Here, we will first discuss a modified synthetic approach to densify the covalent pegylation used to link bio-molecules on the SWCNTs and show results with nanoprobes incubated with T47D antibody (ab) and MDA231 cell lines. The immunofluorescence and Raman imaging data shows that dyes@SWCNT/PEG/ab composites can specifically target cancer cells overexpressing high affinity receptors of the specific biomarkers linked to the probes. By densifying the covalently attached PEGs, the results show higher stability and improved selectivity of the Raman nanoprobes towards bio-molecules on cancer cells.