Previous Research

Nanoparticles for Bioimaging. My earlier research is focused on applications of plasmonic nanoparticles for bioimaging. Specifically, we developed a novel image contrast enhancement mechanism called dynamic contrast, using magnetoplasmonic nanoprobes such as gold nanostars with superparamagnetic cores or iron oxide/gold core-shell nanoparticles as image contrast agents. Dynamic contrast is generated in two steps: 1) signal modulation, to introduce periodic changes of optical signals in the time domain, and 2) demodulation, to recover signals and reduce backgrounds in the frequency domain. Image contrast enhancement is achieved by suppressing nonmodulated background noise in the Fourier domain through computational imaging. We demonstrated two orders of magnitude signal-to-background ratio (SBR) enhancement in detection of single nanoprobes in high background noise tumor cells. We also demonstrated that dynamic contrast is a universal contrast enhancement mechanism where the modulation could be various types such as optical, photothermal, or magnetomotive in nature. Therefore, the concept has been widely adopted in many other imaging modalities such as fluorescence microscopy, optical coherence tomography (OCT), photoacoustic tomography (PAT), and ultrasound.

  1. W. Xia, H.-M. Song, Q. Wei, and A. Wei. Differential Response of Macrophages to Nanoparticles and Nanostars. Nanoscale 2012, 4, 7143-7148
  2. Q. Wei and A. Wei. Optical Imaging with Dynamic Contrast Agents. Chem. Eur. J. 2011, 17, 1080-1091
  3. H.-M. Song, Q. Wei, Q. K. Ong, and A. Wei. Plasmon-Resonant Nanoparticles and Nanostars with Magnetic Cores: Synthesis and Magnetomotive Imaging. ACS Nano 2010, 4, 5163-5173.
  4. Q. Wei, H.-M. Song, A. P. Leonov, J. A. Hale, D. Oh, Q. K. Ong, K. Ritchie, and A. Wei. Gyromagnetic Imaging: Dynamic Optical Contrast Using Gold Nanostars with Magnetic Cores. J. Am. Chem. Soc. 2009, 131, 9728-9734

 

Nanomedicine. Earlier in my career, I also contributed extensively in the area of nanomedicine by using gold nanorods as a versatile agent for drug delivery, imaging, and photothermal therapy. My research has resulted in the first near infrared (NIR)-responsive drug delivery system based on single gold nanorods by preparing gold nanorod/PNIPAAm core-shell naonhybrids through the first in situ atom transfer radical polymerization (ATRP) on the surface of a single gold nanorod.

  1. W. Zhou, J. Shao, Q. Jin, Q. Wei, J. Tang, and J. Ji. Zwitterionic Phosphorylcholine as a Better Ligand for Gold Nanorods Cell Uptake and Selective Photothermal Ablation of Cancer Cells. Chem. Commun. 2010, 46, 1479-1481
  2. L. Tong, Q. Wei, A. Wei, and J.-X. Cheng. Gold Nanorods as Contrast Agents for Biological Imaging: Optical Properties, Surface Conjugation and Photothermal Effects. Photochem. Photobiol. 2009, 85, 21-32
  3. W. He, W. A. Henne, Q. Wei, Y. Zhao, D. D. Doorneweerd, J.-X. Cheng, P. S. Low, and A. Wei. Two-Photon Luminescence Imaging of Bacillus Spores Using Peptide-Functionalized Gold Nanorods. Nano Res. 2008, 1, 450-456
  4. Q. Wei, J. Ji, and J. Shen. Synthesis of Near-Infrared Responsive Gold Nanorod/PNIPAAm Core/Shell Nanohybrids via Surface Initiated ATRP for Smart Drug Delivery. Macromol. Rapid Commun. 2008, 29, 645-650

 

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