My research is exploring nanobiotechnology with the focus on developing novel, ultrasensitive, and practical technique for microscopic and spectroscopic detection of cancer biomarker in live cell, fixed tissue specimen and in vivo animal model.  This work involves multidisciplinary collaboration of physical science, material chemistry, cancer biology and biomedical engineering.

The current project is mainly based on Surface Enhanced Raman Scattering (SERS) spectroscopy.  SERS is an ultra-sensitive tool (down to single molecule sensitivity).  Using gold or silver nanoparticles or substrates, SERS can be applied to detect trace amount of biomolecules such as hemoglobin, glucose, cancer genes, pathogens, biological toxins and viruses.  However, it is also well-known that uncontrollable nano-aggregates lead to irreproducible SERS signal.  Recently, we have conquered a major bottleneck problem of controlling the aggregation stage of nanoparticles by encapsulating a thin layer of PEG polymer coating on SERS active nanoparticles.  In addition, the use of heterobifunctional PEG provides a platform for efficient conjugation of biological targeting ligands.  This design has laid the foundation for practical bioanalytical applications and has enabled us to achieve in-vivo active tumor targeting.

Publications and Presentation

Publications:
X.-M. Qian, X.H. Peng, M. Mancini and S. Nie, "Polyethylene glycol (PEG) chain length affecting plasma protein association and in vivo biodistribution of gold nanoparticles", in preparation.

X.-M. Qian and S. Nie, "Pegylated Surface enhanced Raman Scattering (SERS) Nanoparticles at extreme pH", in preparation.

X.-M. Qian and S. Nie, "Single-Molecule and Single-Nanoparticle SERS: from Fundamental Mechanisms to Biomedical Applications", Chem. Soc.  Rev. submitted.

X.H. Peng, X.-M. Qian, H. Mao, A. Y. Wang, G. Z. Chen, S. Nie and D. M. Shin, "Targeted magnetic iron oxide nanoparticles for tumor imaging and therapy", Int. J. Nanomed. submitted.

X.-M. Qian, X.H. Peng, D. Ansari, Q. Yin-Goen, G.Z. Chen, D.M. Shin, L. Yang, A.N. Young, D. Wang and S. Nie, "In-vivo tumor targeting and spectroscopic detection with surface enhanced Raman nanoparticle tags", Nature Biotech., 26(1), 83 (2008).

X.-M. Qian, D. Ansari and S. Nie, "A new class of nontoxic nanoparticle tags based on surface enhanced Raman scattering", Proc. SPIE Vol. 6448, 64480O (2007).

H.J. Worner, X.-M. Qian, F. Merkt, "Jahn-Teller effect in tetrahedral symmetry: Large-amplitude tunneling motion and rovibronic structure of CH4+ and CD4+", J. Chem. Phys., 126(14), 144305 (2007).

M.K. Bahng, X. Xing, S.J. Baek, X.-M. Qian and C.Y. Ng, "A combined VUV synchrotron pulsed field ionization-photoelectron and IR-VUV laser photoion depletion study of ammonia", J. Phys. Chem. A, 110(27), 8488 (2006).

M. Hochlaf, T. Baer, X.-M. Qian and C.Y. Ng, "A vacuum ultraviolet pulsed field ionization - photoelectron study of cyanogens cation in the energy range of 13.2-15.9 eV", J. Chem. Phys., 123, 144302 (2005).

J. Yang, Y. Mo, K.C. Lau, Y. Song, X.-M. Qian and C.Y. Ng, "A combined vacuum ultraviolet laser and synchrotron pulsed field ionization study of BCl3", Phys. Chem. Chem. Phys., 7, 1518 (2005).

X.-M. Qian, K.C. Lau and C.Y. Ng, "A High-Resolution Pulsed Field Ionization Photoelectron Photoion Coincidence Study of Vinyl Bromide", J. Chem. Phys., 120(23), 11031 (2004).

X.-M. Qian, K.C. Lau, G.Z. He, C.Y. Ng, and M. Hochlaf, "Vacuum Ultraviolet Pulsed Field Ionization Study of ND3: Accurate Thermochemistry for the ND2-ND2+ and ND3-ND3+ system", J. Chem. Phys., 120(18), 8476 (2004).

X.-M. Qian, A.H. Kung, T. Zhang and C.Y. Ng, "Rovibrational-State-Selected Photoionization of Acetylene by the Two-Color IR + VUV Scheme: Observation of Rotationally Resolved Rydberg Transitions", Phys. Rev. Lett., 91(23), 233001 (2003).

T. Zhang, X.-M. Qian, X.N. Tang, Y.-H. Chiu, D. Levandier, J. Miller, R. Dressler and C.Y. Ng, "A state-selected study of the H2+ (X, v+ = 0–17, N+ = 1) + Ne proton transfer reaction using the pulsed-field ionization–photoelectron–secondary ion coincidence scheme", J. Chem. Phys., 119(19), 10175 (2003).

X.-M. Qian, T. Zhang, C. Chang, P. Wang, C.-Y. Ng, Y.-H. Chiu, D. Levandier, J. Miller, R. Dressler T. Baer, and D. Peterka, "High-resolution state-selected ion-molecule reaction studies using pulsed field ionization photoelectron-secondary ion coincidence method", Rev. Sci. Instrument, 74(9), 4096 (2003).

X.-M. Qian, T. Zhang, C.Y. Ng, A.H. Kung, and M. Ahmed, "Two-color photoionization spectroscopy using vacuum ultraviolet synchrotron radiation and infrared optical parametric oscillator laser", Rev. Sci. Instrument, 74(5), 2784 (2003).

X.-M. Qian, T. Zhang, Y.-H. Chiu, D. Levandier, J. Miller, R. Dressler and C.Y. Ng, "Rovibrational state-selected study of H2+ (X, + = 0–17,  N+ = 1) + Ar using the pulsed field ionization-photoelectron-secondary ion coincidence scheme", J. Chem. Phys., 118 (6), 2455 (2003).

J.B. Liu, W.W. Chen, M. Hochlaf, X.-M. Qian, C. Chang, and C.Y. Ng, "Unimolecular decay pathways of state-selected CO2+ in the internal energy range of 5.2-6.2 eV: An experimental and theoretical study", J. Chem. Phys., 118 (1), 149 (2003).

X.-M. Qian, Y. Song, K.-C. Lau, C.Y. Ng, J. Liu, W. Chen and G. He, "A pulsed field ionization photoelectron-photoion coincidence study of the dissociative photoionization process D2O+h→OD++D+e-", Chem. Phys. Lett., 353 (1-2), 19 (2002).

Y. Song, X.-M. Qian, K.-C. Lau and C.Y. Ng, "A pulsed field ionization study of the dissociative photoionization reaction CD4+h→CD3++D+e-", Chem. Phys. Lett., 347 (1-3), 51 (2001).

Y. Song, X.-M. Qian, K.-C. Lau, C.Y. Ng, J. Liu and W. Chen, "High-resolution energy-selected study of the reaction CH3X+CH3+ + X: Accurate thermochemistry for the CH3X/CH3X+ (X=Br, I) system", J. Chem. Phys., 115 (9), 4095 (2001).

X.-M. Qian, Yang Song, C.-W. Hsu and C.-Y. Ng, "Rotationally resolved pulsed field ionization photo-electron spectra of N2+ (X 2Sg+) and (A 2Pu) state", ACS 2001 conference paper.

Song, Y., Qian, X.-M., Lau, K.-C., Ng, C.Y., Liu J. and Chen W., "High-resolution energy-selected study of the reaction NH3+-> NH2++H: Accurate thermochemistry for the NH2/NH2+ and NH3/NH3+ systems", J. Chem. Phys., 115 (6), 2582 (2001).

Yunqi Liu, Daoben Zhu, Maofa Ge, Ximei Qian, Xinjiang Zhu and Dianxun Wang, "Theoretical and HeI photoelectron spectroscopic (PES) studies on the molecular and electronic structures of a novel asymmetrically substituted phthalocyanine", J. Electron Spectro. & Relat. Phenom., 108 (1-3), 213 (2000).

Xiaoyan Cao, Ximei Qian, Chunhua Qiao and Dianxun Wang, "A kinetic study of the isomerization reaction from SSF2 to FSSF using the HeI photoelectron spectroscopic method", Chem. Phys. Lett., 299 (3-4), 322 (1999).

Dianxun Wang, Chunhui Li, Ximei Qian and Gamblin, S.D., "An HeI photoelectron spectrum of bromine atoms - The use of SiBr4 as a bromine atom source", J. Electron Spectro. & Relat. Phenom., 97 (1-2), 59 (1998).

Dianxun Wang, Peng Jiang, Ximei Qian and Gongyi Hong, "Response to "Comment on 'A study of Hel photoelectron spectroscopy on the electronic structure of the nitrate free radical NO3'"", J. Chem. Phys. 108, 1293 (1998).

Dianxun Wang, Ximei Qian, Shijun Zheng and Yizhong Shi, "A HeI photoelectron spectrum of the [Al(CH3)(3)]2 dimmer", Chem. Phys. Lett. 277, 502 (1997).

Peng Jiang, Ximei Qian, Chunhui Li, Chunhua Qiao and Dianxun Wang, "HeI photoelectron spectroscopic studies on the electronic structure of alkyl nitrosamines", Chem. Phys. Lett. 277, 508 (1997).

Dianxun Wang, Ximei Qian and Qiyuan Zheng, "The isonitrile-nitrile isomerization: Kinetic parameters, reaction mechanism and relative photoionization cross-section of the HOMO. A HeI photoelectron spectroscopy study", Chem. Phys. Lett. 266, 560 (1997).

Dianxun Wang and Ximei Qian, "Determination of the kinetic parameters of the isomerization reaction of ethyl isocyanide using HeI photoelectron spectroscopy", J. Electron Spectro. & Relat. Phenom., 83, 41 (1997).

Dianxun Wang, Peng Jiang, Ximei Qian and Gongyi Hong, "A study of HeI photoelectron spectroscopy on the electronic structure of the nitrate free radical NO3", J. Chem. Phys. 106 (8), 3003 (1997).

Dianxun Wang, Ximei Qian and Shijun Zheng, "A linear relation between the ionization potentials of HeI photoelectron spectroscopy and NMR chemical shifts. A PES study of the electronic structure of alkyl isocyanides", Chem. Phys. Lett. 262, 776 (1996).

Dianxun Wang, Ximei Qian, and Peng Jiang, "A novel method for the kinetic study of a chemical reaction. Determination of the kinetic parameters of the isomerisation reaction of methyl isocyanide using HeI photoelectron spectroscopy", Chem. Phys. Lett. 258, 149 (1996).

Oral and Poster Presentations:
X.-M. Qian and S. Nie, "Bioconjugated SERS Nanoparticle Tags for Cancer Detection", FACSS2007, Invited Talk, Memphis, Tennessee, Oct. 14-18, 2007.

X.-M. Qian and S. Nie, "Surface Enhanced Raman Scattering (SERS) Spectroscopic Applications in Cancer Detection", CSIXXXV, Invited Keynote Lecture, Xiamen, CHINA, Sept. 23-27, 2007.

X.-M. Qian, D. Ansari, X.H. Peng, G. Ruan, B. Kairdolf, L. Yang and S. Nie, "A new class of nanoparticle tags based on surface enhanced Raman scattering for in vitro and in vivo detection of cancer biomarkers", 2nd Emory-Georgia Tech Frontiers of Cancer Nanotechnology Symposium, Poster Contribution, Pine Mountain, Georgia, April 2-3, 2007.

X.-M. Qian, J. Li and S. Nie, "Multi-functional Au-PEG-Doxorubicin-Folate drug nanocarrier for in vitro cellular targeting and drug efficacy study", 2nd Emory-Georgia Tech Frontiers of Cancer Nanotechnology Symposium, Poster Contribution, Pine Mountain, Georgia, April 2-3, 2007.

X.-M. Qian and S. Nie, "A new class of nontoxic nanoparticle tags based on surface enhanced Raman scattering", Oral Contribution, BiOS 2007 & SPIE Photonics West, San Jose,  California, Jan. 20-25, 2007.  

A. Agrawal, T. Sathe, G. Ruan, X.-M. Qian, Y. Xing and S. Nie, "Nanotechnology for In Vitro Cancer Diagnostics", Poster Contribution, 1st Emory-Georgia Tech Frontiers of Cancer Nanotechnology Symposium, Braselton, Georgia, March 27 & 28, 2006.

X.-M. Qian and F. Merkt, "A high-resolution laser vacuum ultraviolet pulsed field ionization photoelectron spectroscopic study of CH3F+ radical cation (X+ 2E)", Poster Contribution, 28th International symposium on free radicals, Leysin, Switzerland, Sept. 4-9, 2005

X.-M. Qian, C.Y. Ng, F. Merkt, "IR-VUV Double Resonance Photoionization Spectroscopy", Oral Contribution, 3rd Swiss Snow Symposium, Stechelberg, Switzerland, February 18-20, 2005

X.-M. Qian, H.J. Woener, F. Merkt, "Understanding Static and Dynamic Jahn-Teller Effect on Spherical Molecules 3/4 Rotational State Assignment of PFI Photoelectron Spectra of Methane by IR-VUV Two Photon Excitation Scheme", Poster Contribution, 8th ECAMP conference, Rennes, France, July 06-10, 2004

X.-M. Qian, "Applications of Third Generation Synchrotron Radiation in Vacuum Ultra-Violet (VUV) Photoionization Spectroscopy and Dynamics", Invited Talk, Univ. California at Davis, Award Seminar, June 05, 2003

X.-M. Qian, A. Kung, T. Zhang and C.-Y. Ng, "VUV-IR and IR-VUV Photoinduced Rydberg Autoionization of Ar and C2H2", Poster Contribution, 225th ACS National Meeting, New Orleans, March 23-27, 2003

X.-M. Qian, A. Kung, T. Zhang and C.-Y. Ng, "VUV-IR and IR-VUV Photoionization Spectroscopy at the ALS", Oral Contribution, ALS Users’ Meeting, Berkeley, October 10-12, 2002

X.-M. Qian, Y.-H. Chiu, D. Levandier, S. Miller, R. Dressler, T. Zhang and C.-Y. Ng, "State-selected Ion-molecule Reaction Dynamics at Extremely High Vibrationally Excited States", Poster Contribution, ALS Users' Meeting, Berkeley, October 10-12, 2002

X.-M. Qian, A. Kung, C.-H. Lim, T. Zhang and C.-Y. Ng, "IR-Pump State-Selected VUV Photo-ionization Spectroscopy of Acetylene (C2H2) in Ground State", Poster Contribution, ALS Users' Meeting, Berkeley, October 15-17, 2001

X.-M. Qian, Y. Song, T. Zhang, H.-K. Woo, C.Y. Ng, Y.-H. Chiu, D. Levandier, S. Miller and R. Dressler, "State-Selected Ion-Molecule Reaction Dynamics Using Photoionization Techniques", Poster Contribution, Gordon Research Conference: Photoions: Photoionization and Photodetachment, Williamstown, July 8-13, 2001

X.-M. Qian, Y. Song, J. Liu, W. Chen and C.Y. Ng, "High Resolution Pulsed Field Ionization Photoelectron-Photoion Coincidence (PFI-PEPICO) Study of  Freon Compounds", Oral Contribution, 221st ACS National Meeting, San Diego, April 1-5, 2001.

X.-M. Qian "High Resolution Pulsed Field Ionization Photoelectron-Photoion Coincidence (PFI-PEPICO) Studies of  Monomolecular Dissociation Reactions", Oral Contribution, 8th International Conference on Electronic Spectroscopy & Structure, Berkeley, August 8-12, 2000.