Group of Dr. H. W. Li
Group of Dr. H.W. Li (2012-2013)
DSCN2092.JPG
 
Our group is interested in the study of biomolecular interaction and biomarker sensing with the aid of fluorescence microscopic methods. Recently, we have

(1)developed ultrasensitive assays for the detection of potent cancer markers, e.g. microRNA
(2)studied the inhibitory effect of nanomaterials and transition metal complexes on regulating the fibrillogenesis of Alzheimer’s disease-related beta-amyloid peptide, respectively.
 
(a) Direct Quantification of Single-Molecule of MicroRNA by Total Internal Reflection Fluorescence Microscopy (TIRFM)

MicroRNAs (miRNAs) are regarded as potent cancer biomarker since they express differently in normal and cancerous tissues. However, the short length and low abundance of microRNAs brought challenges to the established biomolecular detection assays. Herein, we have:

Developed an ultrasensitive, low sample-consumption and pretreatment-free detection assay of miRNAs in single-molecule level with TIRF microscopy; and
Quantified the expression of miRNAs in cancerous and non-cancerous cells and validated the result with RT-qPCR method.



(b) Inhibition of Beta-Amyloid Fibrillogenesis by Nanoparticles, Quantum Dots and Group 9 Metal Solvato Complexes

Beta-amyloid peptide (Aβ) is found highly correlated to the occurrence of Alzheimer’s disease (AD). It is believed that preventing the misfolding and self-aggregation of monomeric Aβ into neurotoxic fibrils is one of the therapeutic strategies of AD. We are interested in exploring the effect of different materials on the growth of Aβ fibrils. With TIRFM, we have studied the inhibition of Aβ with:

•  Surface functionalized CdTe quantum dots
•  Surface functionalized gold nanoparticles
•  Group 9 metal solvato complexes
•  Organic small molecules



 
Selected Publications
  1. W.G. Yang, Y. Wong, O.t.W. Ng, L.P. Bai, D.W.J. Kwong, Y. Ke, Z.H. Jiang, H.W. Li, K.K.L. Yung and M.S. Wong, "Inhibition of Beta-Amyloid Peptide Aggregation by Multifunctional Carbazole-Based Fluorophores", Angew. Chem.-Int. Edit., 51(8), 1804-1810 (2012).
  2. H.M. Chan, L.H. Xiao, K.M. Yeung, S.L. Ho, D. Zhao, W.H. Chan and H.W. Li, "Effect of Surface-functionalized Nanoparticles on the Elongation Phase of Beta-amyloid (1-40) Fibrillogenesis", Biomaterials33(18), 4443-4450 (2012).
  3. Bradley Yat-Wah Man, Ho-Man Chan, Chung-Hang Leung, Daniel Shiu-Hin Chan, Li-Ping Bai, Zhi-Hong Jiang, Hung-Wing Li, Dik-Lung Ma, "Group 9 metal-based inhibitors of b-amyloid (1-40) fibrillation as potential therapeutic agents for Alzheimer's disease", Chem Sci., 2, 917-921(2011).
  4. H.M. Chan and H.W. Li, "Multifunctional Encoded Self-assembling Protein Nanofibrils as Platform for High-Throughput and Multiplexed Detection of Biomolecules", Anal. Chem., 83(24), 9370-9377 (2011).
  5. Lehui Xiao, Dan Zhao, Wing-Hong Chan, Martin M.M. Choi, Hung-Wing Li, "Inhibition of beta 1-40 amyloid fibrillation with N-acety-L-cysteine capped quantum dots", Biomaterials31, 91-98, (2010)
  6. H.M. Chan, L.S. Chan, R.N.S. Wong and H.W. Li, "Direct Quantification of Single-Molecules of MicroRNA by Total Internal Reflection Fluorescence Microscopy", Anal. Chem., 82(16), 6911-6918 (2010).
  7. Rebecca R. Pompano, Hung-Wing Li, Rustem F. Ismagilov, "Rate of Mixing Controls Rate and Outcome of Autocatalytic Processes: Theory and Microfluidic Experiments with Chemical Reactions and Blood Coagulation"Biophysical J.95(3)531-1543 (2008).
  8. Rafe T. Petty, Hung-Wing Li, Jane H. Maduram, Rustem Ismagilov and Milan Mrksich, "Attachment of Cells to Islands Present Gradients of Adhesion Ligands", J. Am. Chem. Soc. (Communication)129(29), 8966-8967 (2007).
  9. H.W. Li, M. McCloskey, Y. He and Edward .S. Yeung, "Real-time Dynamics of Label-free Single Mast Cell Granules Revealed by Differential Interference Contrast Microscopy", Anal. Bioanal. Chem., 387(1), 63-69 (2007).
  10. S. Isailovic, H.W. Li, Edward S Yeung, "Adsorption of Single DNA Molecules at the Water/fused-silica Interface", J. Chromatography A., 1, 259-266 (2007).
  11. N. Fang, H. Zhang, J.W. Li, H.W. Li, Edward S. Yeung, "Mobility-Based Wall Adsorption Isotherms for Comparing Capillary Electrophoresis with Single-Molecule Observations", Anal. Chem., 79(16), 6047 -6054 (2007).
  12. H. Song, H.W. Li, M. Munson, T. Van Ha and R.F. Ismagilov, "On-chip Titration of an Anticoagulant Argatroban and Determination of Clotting Time within Whole Blood or Plasma Using a Plug-based Microfluidic System", Anal. Chem.78(14), 4839-4849 (2006).
 
Lab equipment

Total Internal Refraction Microscope