(649d) A Fluorescent Single-Walled Carbon Nanotube “Chaperone Sensor” for Explosive and Pesticide Compounds
Photoluminescent single walled carbon nanotubes (SWNT) transduce specific changes in peptide secondary structure, resulting in single-molecule detection of nitroaromatic compounds such as the explosive RDX and pesticides TFM and 2,4-dinitrophenol. Peptide-nanotube complexes report modulation of peptide conformation upon analyte binding via changes in SWNT photoluminescence wavelength. The fluorescence modulation is differentiable between analytes, resulting in compound identification via specific SWNT spectral fingerprint. A novel split-channel microscope constructed to image quantized spectral wavelength shifts in real-time, in response to nitroaromatic adsorption, results in single-molecule stochastic imaging of solvatochromic events. The indirect detection mechanism demonstrates that functionalization of the carbon nanotube surface can result in unique sites for molecular recognition, resolvable at the single molecule level.