Phone: (864) 656-4065
Office: 365 Hunter Laboratories
Dr. McNeill earned a B.S. in Chemistry (1991) from Northern Illinois University and a Ph.D. (1999) from the University of California at Berkeley. He conducted postdoctoral research at the University of Texas at Austin. In 2006 he received the CAREER Award from the National Science Foundation.
Conjugated Polymer Nanoparticles
We are currently developing novel probes for advanced fluorescence applications based on nanoparticles consisting of one or more conjugated polymer molecules. The nanoparticle size can be controlled over the range of ~3 nm in diameter (single polymer molecules) to ~100 nm in diameter. These nanoparticles have unique optical properties and many possible biological imaging applications such as single nanoparticle sensors, tracking of single biomolecules, and ultra-resolution imaging. Conjugated polymer nanoparticles are arguably the brightest small fluorescent nanoparticles--roughly 30 times brighter than similar-sized CdSe quantum dots. The nanoparticles also exhibit highly efficient energy transfer. We are currently developing a number of sensor architectures that take advantage of the extraordinarily high brightness and energy transfer characteristics of these nanoparticles.
Left: Photo of various polymer dot nanoparticles suspended in water, under UV excitation. Right: AFM of polymer dot nanoparticles dispersed on a mica substrate.
Intracellular Single Molecule Dynamics
Our development of ultra-bright nanoparticles has made it possible to detect the fluorescence of isolated nanoparticles 5-10 nm in diameter inside a living cell. We have demonstrated 1 nm tracking resolution in cells at video rate. The high brightness, relatively small size, and excellent photostability of the nanoparticles are ideal for either short or long-term tracking of biomolecules with subwavelength precision inside living cells, where autofluorescence and scattering effects typically drown out the fluorescence signal of individual dyes and nanoparticles, rendering single molecule tracking difficult or impossible.
Left: Multiphoton-excited fluorescence image of single conjugated polymer nanoparticles. Right: Fluorescence image of macrophage cells loaded with ~5-10 nanoparticles per cell, overlaid with DIC image.
Yu, J; Wu, C.; Tian, Z.; McNeill, J., Tracking of Single Charge Carriers in a Conjugated Polymer Nanoparticle. Nano Lett. 2012, 12, 1300.
Grimland, J. L.; Wu, C.; Ramoutar, R. R.; Brumaghim, J. L.; McNeill, J., Photosensitizer-doped conjugated polymer nanoparticles with high cross-sections for one- and two-photon excitation. Nanoscale 2011, 3, 1451.
Wu, C.; Hansen, S. J.; Hou, Q.; Yu, J.; Zeigler, M.; Jin, Y.; Burnham, D. R.; ; McNeill, J. D.; Olson, J. M.; Chiu, D. T., Design of Highly Emissive Polymer Dot Bioconjugates for In Vivo Tumor Targeting. Angew. Chem. Int. Ed. 2011, 50, 3430.
Fernando, L. P.; Kandel, P. K.; Yu, J. B.; McNeill, J.; Ackroyd, P. C.; Christensen, K. A., Mechanism of Cellular Uptake of Highly Fluorescent Conjugated Polymer Nanoparticles. Biomacromol. 2010, 11, 2675.
Tian, Z. Y.; Yu, J. B.; Wu, C. F.; Szymanski, C.; McNeill, J., Amplified energy transfer in conjugated polymer nanoparticle tags and sensors. Nanoscale 2010, 2, 1999.
Wu, C. F.; Schneider, T.; Zeigler, M.; Yu, J. B.; Schiro, P. G.; Burnham, D. R.; McNeill, J. D.; Chiu, D. T., Bioconjugation of Ultrabright Semiconducting Polymer Dots for Specific Cellular Targeting. J. Amer. Chem. Soc. 2010, 132, 15410.
Wu, C. F.; Bull, B.; Christensen, K.; McNeill, J., Ratiometric Single-Nanoparticle Oxygen Sensors for Biological Imaging. Angew. Chem. Int. Ed. 2009, 48, 2741.
Yu, J. B.; Wu, C. F.; Sahu, S. P.; Fernando, L. P.; Szymanski, C.; McNeill, J., Nanoscale 3D Tracking with Conjugated Polymer Nanoparticles. J. Amer. Chem. Soc. 2009, 131, 18410.
Zhang, Q.; Iwakuma, N.; Sharma, P.; Moudgil, B. M.; Wu, C.; McNeill, J.; Jiang, H.; Grobmyer, S. R., Gold nanoparticles as a contrast agent for in vivo tumor imaging with photoacoustic tomography. Nanotechnology 2009, 20, 395102/1.
Wu, C.; Bull, B.; Szymanski, C.; Christensen, K.; McNeill, J., Multicolor Conjugated Polymer Dots for Biological Fluorescence Imaging. ACS Nano 2008,, 2415.
Wu, C. F.; McNeill, J., Swelling-controlled polymer phase and fluorescence properties of polyfluorene nanoparticles. Langmuir 2008, 24, 5855.
Wu, C.; Zheng, Y.; Szymanski, C.; Daniel. C.; McNeill, J. D., Energy Transfer in a Nanoscale Multichromophoric System: Dye Doped Conjugated Polymer Nanoparticles, J. Phys. Chem. C 2008, 112, 1772.