Dongmao Zhang

Image of Dongmao Zhang

Dongmao Zhang

Associate Professor

B.S. Wuhan University, 1987
Ph.D. Purdue University, 2002

Email

Hand Lab 2209

(662) 325-6752

Website CV

Research Interests

Current research in our group has been focused on the following three areas. 

Nanoparticle Interfacial Interactions

We are interested in the ligand adsorption, desorption, displacement, and reaction on the plasmonic gold nanoparticle and silver nanoparticles (AuNPs and AgNPs).  The model ligands include proteins, DNA, and small molecules such as electrolytes, organothiols, thioamides, and other organic species.  The most significant new findings from our studies includes 1) organothiols binding to AuNPs differs significantly from that to AgNPs.  While the mono- and di-thiol forms monolayer binding to AuNPs, they continuously react with AgNPs until total consumption of the AgNPs or the organothiols.1-5  2) Ion pairing, the directly cation and anion coadsorption onto AuNP is an important pathway for electrolyte bindings to AuNPs and it can accounted for a series of experimental observations can’t be explained by the electrical double layer theory.6-8    3) Protein and multicomponent ligand binding to AuNPs is highly dynamic in nature and it is very likely for ligands to reach an equilibrated state on AuNP surfaces.9-12

Optical Spectroscopy

Light/matter interactions are likely the most studied topic in science and the phenomena from light/matter interactions are used extensively for a wide range of material characterizations.  Unfortunately, existing photon absorption, scattering, and fluorescence measurements often ignores the complex interplay of the photon absorption, scattering, and on-resonance emission that can concurrently occur in many realistic samples.  Our group has recently invented a new spectroscopic method termed as “Ratiometric resonance synchronous spectroscopy (R2S2)”.  When used in combination with conventional UV-vis and fluorescence measurements, this R2S2 spectroscopic technique has enables for the first time the quantitative decoupling of the interplay of the material photon absorption, scattering, and on-resonance fluorescence emission.13,14  Current research in this area is on the R2S2 applications in material characterizations.

Analytical Method Design

One everlasting demand in chemical/biochemical analysis is increasingly higher sensitivity, accuracy, and efficiency.  Research in this area has been focused on developing internally referenced analytical methods by using the solvent or the isotope-substituted analyte as the internal reference for improving quantification accuracy.  We have already conducted a series of proof-of-concept studies with protein and carbohydrate samples.15-20  Ongoing research in this area is on the comparative proteomic and glycomic quantification using the isotope-substitute tagging studies. 

Positions Open

We are always looking for quality graduate and undergraduate researchers to join our research team. Graduate students interested in joining the lab should have a strong passion and determination for scientific discovery and technological advance.  For undergraduates, advanced coursework is not required provided you possess genuine enthusiasm and interest in chemical measurements and material characterizations.

Publications

1. Gadogbe, M.; Zhou, Y.; Alahakoon, S. H.; Perera, G. S.; Zou, S.; Pittman, C. U.; Zhang, D.  Structures and Conformations of Alkanedithiols on Gold and Silver Nanoparticles in Water, J. Phys. Chem. C 2015, 119, 18414-18421.  Link

2. Gadogbe, M.; Ansar, S. M.; Chu, I. W.; Zou, S.; Zhang, D.  Comparative study of the self-assembly of gold and silver nanoparticles onto thiophene oil, Langmuir 2014, 30, 11520-11527. Link

3. Ansar, S. M.; Gadogbe, M.; Siriwardana, K.; Howe, J. Y.; Dogel, S.; Hosseinkhannazer, H.; Collier, W. E.; Rodriguez, J.; Zou, S.; Zhang, D.  Dispersion Stability, Ligand Structure and Conformation, and SERS Activities of 1-Alkanethiol Functionalized Gold and Silver Nanoparticles, J.    Phys. Chem. C 2014, 118, 24925-24934. Link

4. Ansar, S. M.; Perera, G. S.; Gomez, P.; Salomon, G.; Vasquez, E. S.; Chu, I. W.; Zou, S.; Pittman, C. U.; Walters, K. B.; Zhang, D.  Mechanistic Study of Continuous Reactive Aromatic Organothiol Adsorption onto Silver Nanoparticles, J. Phys. Chem. C 2013, 117, 27146-27154. Link

5. Ansar, S. M.; Haputhanthri, R.; Edmonds, B.; Liu, D.; Yu, L.; Sygula, A.; Zhang, D.  Determination of the Binding Affinity, Packing, and Conformation of Thiolate and Thione Ligands on Gold Nanoparticles, J. Phys. Chem. C 2011, 115, 653-660. Link

6. Perera, G. S.; Yang, G.; Nettles, C. B.; Perez, F.; Hollis, T. K.; Zhang, D.  Counterion Effects on Electrolyte Interactions with Gold Nanoparticles, The Journal of Physical Chemistry C 2016, ASAP. Link

7. Perera, G. S.; Gadogbe, M.; Alahakoon, S. H.; Zhou, Y.; Zou, S.; Perez, F.; Zhang, D.  Ion Pairing as the Main Pathway for Reducing Electrostatic Repulsion among Organothiolate Self-assembled on Gold Nanoparticles in Water, The Journal of Physical Chemistry C 2016, 120,  19878-19884. Link

8. Perera, G. S.; Nettles, C. B., 2nd; Hollis, T. K.; Zhang, D.; Zhou, Y.; Zou, S.  Direct Observation of Ion Pairing at the Liquid/Solid Interfaces by Surface Enhanced Raman Spectroscopy, Langmuir 2015, 31, 8998-9005. Link

9. Siriwardana, K.; La Cour, A.; Zhang, D.  Critical Sequence Dependence in Multicomponent Ligand Binding to Gold Nanoparticles, J. Phys. Chem. C 2016, Ahead of Print. Link

10. Zhang, D.; Siriwardana, K.; Vangala, K.; Fitzkee, N. C.; Wang, A.  Probing the Effects of Cysteine Residues on Protein Adsorption onto Gold Nanoparticles using Wild-type and Mutated GB3 Proteins, Langmuir 2013. Link

11. Vangala, K.; Siriwardana, K.; Vasquez, E. S.; Xin, Y.; Pittman, C. U.; Walters, K. B.; Zhang, D.  Simultaneous and Sequential Protein and Organothiol Interactions with Gold Nanoparticles, J. Phys. Chem. C 2013, 117, 1366-1374. Link

12. Vangala, K.; Ameer, F.; Salomon, G.; Le, V.; Lewis, E. A.; Liu, D.; Yu, L.; Zhang, D.  Studying Protein and Gold Nanoparticle Interaction Using Organothiols as Molecular Probes, The Journal of Physical Chemistry C 2012. Link

13. Siriwardana, K.; Nettles, C. B.; Vithanage, B. C. N.; Zhou, Y.; Zou, S.; Zhang, D.  On-Resonance Fluorescence, Resonance Rayleigh Scattering, and Ratiometric Resonance Synchronous Spectroscopy of Molecular- and Quantum Dot-Fluorophores, Analytical Chemistry 2016, 88, 9199-9206. Link

14. Nettles, C. B.; Zhou, Y.; Zou, S.; Zhang, D.  UV-Vis Ratiometric Resonance Synchronous Spectroscopy for Determination of Nanoparticle and Molecular Optical Cross Sections, Anal. Chem. (Washington, DC, U. S.) 2016, 88, 2891-2898. Link

15. Suwandaratne, N.; Hu, J.; Siriwardana, K.; Gadogbe, M.; Zhang, D.  Evaluation of Thiol Raman Activities and pKa Values Using Internally Referenced Raman-Based pH Titration, Anal. Chem. (Washington, DC, U. S.) 2016, 88, 3624-3631. Link

16. Nettles, C. B.; Hu, J.; Zhang, D.  Using Water Raman Intensities To Determine the Effective Excitation and Emission Path Lengths of Fluorophotometers for Correcting Fluorescence Inner Filter Effect, Anal. Chem. (Washington, DC, U. S.) 2015, 87, 4917-4924. Link

17. Zhang, D.; Vangala, K.; Li, S.; Yanney, M.; Xia, H.; Zou, S.; Sygula, A.  Acid cleavable surface enhanced raman tagging for protein detection, Analyst 2011, 136, 520-526. Link

18. Zhang, D.; Ansar, S. M.  Ratiometric surface enhanced Raman quantification of ligand adsorption onto a gold nanoparticle, Anal Chem 2010, 82, 5910-5914. Link

19. Vangala, K.; Yanney, M.; Hsiao, C.-T.; Wu, W. W.; Shen, R.-F.; Zou, S.; Sygula, A.; Zhang, D.  Sensitive carbohydrate detection using surface enhanced Raman tagging, Anal Chem 2010, 82, 10164-10171. Link

20. Zhang, D.; Jiang, D.; Yanney, M.; Zou, S.; Sygula, A.  Ratiometric Raman spectroscopy for quantification of protein oxidative damage, Anal Biochem 2009, 391, 121-126. Link

 

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