Jeffrey N. Anker
Assistant Professor
Analytical Chemistry
Phone: (864) 656-1726
Office: 371 Hunter
E-mail: janker@clemson.edu
Research Interests | Publications
Dr. Anker received his B.S from Yale University and earned his Ph.D. (2005) from The University of Michigan with Prof. Raoul Kopelman working on magnetically modulated fluorescence-based sensors. After graduation, he was an NIH Postdoctoral Fellow at Northwestern University with Prof. Richard Van Duyne, where he developed plasmonics-based nanosensors to measure chemical concentrations and measure binding kinetics. He joined the Clemson faculty in 2008. Dr. Anker is also a member of the Center for Optical Materials Science and Engineering Technologies (COMSET).
Research Interests
Dr. Anker’s research uses a combination of optical spectroscopy and nanoparticle devices to study chemical and biophysical processes. The interdisciplinary research involves development and bioanalytical application of multifunctional plasmonic and fluorescent sensors and effectors. Fluorescent and plasmonic nanoparticles are increasingly used in cellular imaging because they fluoresce and scatter light so brightly that individual nanoparticles can be easily observed over extended periods. In addition, nanoparticles can act as a platform onto which many components can be loaded. By loading new components onto nanoparticle platforms, new properties are created with diverse applications.
Examples include:
1. Suspended Plasmonic arrays:
When the size of noble metal particles is reduced to less than the wavelength of light, the particles intensely absorb and scatter light at wavelengths that depend on the nanoparticle composition, size, shape, and local dielectric environment. When molecules adsorb to the nanoparticle surface, the resulting increase in local refractive index causes the nanoparticle extinction and scattering spectrum to redshift. Tracking this redshift in real-time facilitates the study of molecular binding kinetics and interactions. An important project will study the interactions between plasmonic nanoparticles and adsorbed indicator dyes in order to develop intense and stable sensors. Plasmonic nanoparticles will be synthesized, separated by size and shape, and exposed to indicator dyes. The spectral shifts will be measured as a function of position to reveal the effect of nanoparticle size and shape on the dye plasmon coupling.
2. Smart labels: Modulated optical nanoprobes (MOONs)
A combination of chemical synthesis and physical modifications are used to control the optical, chemical, and magnetic properties of micro- and nano-particles. Vapor depositing an opaque metal onto one hemisphere of a fluorescent nanosphere breaks the nanosphere's optical symmetry so that it reflects and fluoresces light in an orientation-dependent manner. If the nanoparticle is magnetic, it aligns with an external magnetic field and rotates to follow a rotating magnetic field. The particle blinks as it rotates through bright and dark orientations. The blinking signal from these magnetically modulated optical nanoprobes (MagMOONs) can be separated from unmodulated autofluorescence backgrounds. These labels will be exposed to surfaces displaying low levels of captured disease biomarker proteins. The labels will be rotated away from their point of binding using magnetic torques to measure analyte concentration and distinguish analytes based on their bond strength.
3. Intracellular rotational and translational transport.
With the increasing application of nanoparticles for chemical sensors, chemotherapy and photodynamic therapy delivery agents, as well as viral and non-viral transfection vectors, there is a need to study how nanoparticles are transported through cells and tissues. In addition, micro- and nanoparticle transport plays an important role in toxicity and accumulation of nanoparticles from smoking, environmental inhalation, and particles produced in prosthetic joints. The goal of this project is to study transport and mechanical properties of cells by tracking the translation and rotation of individual modulated optical nanoprobes (MOONs). The MOONs are fabricated, as detailed in Projects 1 and 2, to emit an orientation-dependent fluorescence, or light scattering signal and therefore appear to blink when they rotate. Two types of MOONs will be used. Metal hemisphere-capped nanospheres are simple almost spherical MOONs with orientation dependent fluorescence and scattering, while plasmonic nanorods possess bright orientation-dependent plasmonic absorption and scattering for particles down to 20 nm with potentially shape dependent transport rates. Tracking blinking rate and position will enable study of both fundamental mechanical properties of cells and transport mechanisms for intracellular vesicles and membrane bound receptors as a function of position, time, and internal and external stimuli.
Dr. Anker is also co-hosting with Dr. Mefford an exciting symposium on "Frontiers in the Characterization & Control of Magnetic Carriers" at Clemson University, April 26-28th, please register and join us, www.clemson.edu/magmeet.
Publications
1. Anker J.N., Hall W.P., Lambert M.P., Velasco P.T., Mrksich M., Klein W.L., and Richard P. Van Duyne R.P.: “Detection and Identification of Bioanalytes with High Resolution LSPR Spectroscopy and MALDI Mass Spectrometry.” Journal of Physical Chemistry C. ASAP
March 24 (2009).
2. Biggs K.B., Camden J.P., Anker J.N., and Van Duyne R.P.: “Surface-Enhanced Raman Spectroscopy of Benzenethiol Adsorbed from the Gas Phase onto Silver Film over Nanosphere Surfaces: Determination of the Sticking Probability and Detection Limit Time.” Journal of Physical Chemistry A. ASAP March 16 (2009).
3. Anker J.N., Hall W.P., Lyandres O., Shah N.C., Zhao J., Van Duyne R.P.: “Biosensing with Plasmonic Nanosensors.” Nature Materials. 7, 442-453 (2008).
4. Hall W.P., Anker J.N., Lin Y., Modica J., Van Duyne R.P., Lin Y., Mrksich M.: “A Calcium-Modulated Plasmonic Switch.” JACS. 18, 5836–5837 (2008).
5. Anker J.N., Koo Y.E., and Kopelman R.: “Magnetically Controlled Sensor Swarms.” Sensors and Actuators B, 25th Anniversary Jubilee Issue. 121, 83-92, (2007).
6. Huang H., Anker J.N., Wang K., and Kopelman R.: “Magnetically Assisted and Accelerated Non-Planar Self-assembly into Strawberry-like Nano/Microparticles.” Journal of Physical Chemistry B, Festschrift in Honor of Charles Harris. 110, 19929-19934, (2006).
7. McNaughton B.H., Kehbein K., Anker J.N., and Kopelman R.: “A Sudden Breakdown in Linear Response of a Rotationally Driven Magnetic Microparticle and Application to Physical and Chemical Microsensing.” Journal of Physical Chemistry B., Festschrift in Honor of Robert Sibley. 110, 18958-18964, (2006).
8. Lemola K., Ting M., Gupta P., Anker J.N., Chugh A., Good E., Reich S., Tschopp D., Igic P., Elmouchi D., Jongnarangsin K., Bogun F., Pelosi F., Morady F., and Oral H.: “Effects of Two Different Catheter Ablation Techniques on Spectral Characteristics of Atrial Fibrillation.” Journal of American College of Cardiology JACC. 48, 340-348, (2006).
9. McNaughton B.H., Stoica V.A., Anker J.N., Tyner K.M., Clarke R. and Kopelman R.: “Fabrication of Uniform Magnetic Nanoparticles.” Materials Research Society Symposium Proceedings. 899E, 0988-N04-03, (2006).
10. Anker J.N., Behrend C.J., McNaughton B.H., Roberts T.G., and Kopelman R.: “Magnetically Modulated Optical Nanoprobes (MagMOONs) and Systems.” Journal of Magnetism and Magnetic Materials. 293, 655-662, (2005).
11. Behrend C.J., Anker J.N., McNaughton B.H., and Kopelman R.: “Microrheology with Modulated Optical Nanoprobes (MOONs).” Journal of Magnetism and Magnetic Materials. 293, 663-670, (2005).
12. McNaughton B.H., Anker J.N., and Kopelman R.: “Magnetic Microdrill as a Modulated Fluorescent pH Sensor.” Journal of Magnetism and Magnetic Materials. 293, 696-701, (2005).
13. Roberts T.G., Anker J.N., and Kopelman R.: “Magnetically Modulated Optical Nanoprobes (MagMOONS) for Detection and Quantification of Biologically Important Ions against the Natural Background Fluorescence of Intracellular Environments.” Journal of Magnetism and Magnetic Materials. 293, 715-724, (2005).
14. Behrend C.J., Anker J.N., McNaughton B.H., Roberts T.G., Brasuel M., Philbert M.A., and Kopelman R.: “Metal-Capped Brownain and Magnetically Modulated Optical Nanoprobes (MOONs): Micromechanics in Chemical and Biological Microenvironments.” Journal of Physical Chemistry B, Festschrift in honor of Gerald Small. 108, 10408-10414, (2004).
15. Behrend C. J., Anker J.N., and Kopelman, R.: “Brownian Modulated Optical Nanoprobes.” Applied Physics Letters. 84, 154-156, (2004).
16. Agayan R.R., Horvath T., McNaughton B.H., Anker, J.N., and Kopelman R.: “Optical Manipulation of Metal-Silica Hybrid Nanoparticles.” Proc. SPIE. Int. Soc. Opt. Eng. 5514, 502-513, (2004).
17. Anker J.N., Behrend C.J., McNaughton B.H., Roberts T.G., Brasuel M., Philbert M.A., and Kopelman R.: “Characterization and Applications of Modulated Optical Nanoprobes (MOONs).” Materials Research Society Symposium Proceedings. 790, 4.4.1-12, (2004).
18. Yan F., Xu H., Anker J.N., Kopelman R., Ross B., Rehemtulla A., and Reddy R.: “Synthesis and Characterization of Silica-Embedded Iron Oxide Nanoparticles for Magnetic Resonance Imaging.” Journal of Nanoscience and Nanotechnology. 4, 72-76, (2004).
19. Anker J.N. and Kopelman R.: “Magnetically Modulated Optical Nanoprobes.” Applied Physics Letters. 82, 1102-1104, (2003).
20. Anker J.N., Behrend C.J., and Kopelman R.: Aspherical Magnetically Modulated Optical Nanoprobes.” Journal of Applied Physics. 93, 6698-6700, (2003).
21. Anker J.N., Horvath T. D., and Kopelman R.: “Cooking With Nanoparticles: A Simple Method of Forming Pancake, Roll, and Breaded Polystyrene Microparticles.” European Cells and Materials. 3, 95, (2002).
[Top]