Carbon Nanotube-Polymethine Dye Complexes with Strong Photoluminescence William Abbot

Nuffield Foundation “Improve social well-being through education, research and innovation” Nuffield Research Placements – funding to experience a research project environment placements

Carbon Nanotubes Essentially a rolled-up graphene sheet Single-wall and multi-wall varieties Different properties based on how they are rolled up: metallic or semiconducting

Uses of Carbon Nanotubes Materials, composites Electronics Novel methods of drug delivery

Aim of the Project Carbon nanotubes have a huge range of uses Problem with potential toxicity A fast, reliable but portable sensor will be required

Photoluminescence (Fluorescence) in Single-Wall Nanotubes Left: From Photoluminescence on Carbon Nanotubes Right: Energy band gap of SWNTs depends on nanotube diameter: the larger the diameter, the smaller the band gap

The Photoluminescence Spectrum

n = 1, 2, 3, 4, 5 Polymethine Dyes Absorption depends on the length of the chain (the size of n )

Weighing the material Graphite flake SDBS - surfactant Ultrasonication, 20 kHz, 1.25 hours Centrifugation, 30kRPM, 2 hours Mixing with DOB-719 (dye) H2OH2O Carbon nanotube powder Method Spectroscopic analysis

Results Several new peaks at an excitation wavelength of ~735nm appear for CNT+DOB-719

Carbon Nanotube-Dye Interaction

More efficient, so increases intensity of emitted light Carbon Nanotube-Dye Interaction

Conclusion Carbon nanotubes: very promising but potentially harmful Fluorescence enhancing probes for carbon nanotubes are being developed Will soon lead to sensor systems

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