NEAR-INFRARED OPTICAL SENSORS BASED ON SINGLE-WALLED CARBON NANOTUBES.

This study by researchers in the Chemical/Biomolecular Engineering and Chemistry departments at the University of Illinois demonstrated that MatTek’s EpiDermFT full-thickness in vitro human skin tissue equivalent can be used to mimic in vivo human skin tissues in NIR imaging studies. Molecular detection using near-infrared light between 0.9 and 1.3 eV has important biomedical applications because of greater tissue penetration and reduced auto-fluorescent background in thick tissue or whole-blood media. Carbon nanotubes have a tunable near-infrared emission that responds to changes in the local dielectric function but remains stable to permanent photobleaching. In this work, researchers in the Dept. of Chemical and Biomolecular Engineering, and the Dept. of Chemistry at the University of Illinois- Urbana/Champaign report the synthesis and successful testing of solution-phase, near-infrared sensors, with beta-D-glucose sensing as a model system, using single-walled carbon nanotubes that modulate their emission in response to the adsorption of specific biomolecules. (MatTek EpiDermFT in vitro human tissue equivalents were used to mimic in vivo human skin tissues in the NIR imaging studies.) New types of non-covalent functionalization using electron-withdrawing molecules are shown to provide sites for transferring electrons in and out of the nanotube. Researchers also show two distinct mechanisms of signal transduction-fluorescence quenching and charge transfer. The results demonstrate new opportunities for nanoparticle optical sensors that operate in strongly absorbing media of relevance to medicine or biology.

Carbon nanotubes, EpiDerm-FT, EpidermFT tissue sample, Glucose oxidase, Human epidermal tissue, Human epidermal tissue sample, Nanomaterials, Nanoparticles, Near-infrared emission, Near-infrared sensors, Sensing applications, Single-walled carbon nanotubes, Tissue sample, Â-D-glucose sensing

Nanoparticle optical sensors