Research Interest

• Drug discovery on cancer
•  bacterial biofilm
• Micro- and Nanosensors
• Optoelectronics
• Nanomaterials
• Conductive polymers
• Hydrogels for biomedical applications
• Surface chemistry
• Plasma Chemistry

Selected Publications

• X. Yang, H.-F. Ji, “Flexible Nanoribbons Made of A Biamphiphilic Perylene Bisimide Derivative”.

• Santosh, H.-F. Ji, J. Fang, K. Varahramyan. “Simulation and Model of Novel Inductive Microcantilevers”.

Peer Reviewed Journals:

2010

• H. F. Ji, X. Xu, “Hexagonal Organic Nanopillar Array from Melamine-Cyanuric Acid Complex”, Langmuir, 2010, 26, 4620-4622. (PDF file)
• L. Zhao, A. Bulhassan, G. Yang, H.-F. Ji, J. Xi, “Real-Time Detection of the Morphological Change in Cellulose by A Nanomechanical Sensor”, Biotech. Bioeng. 2010,  (PDF file)
• H. F. Ji, B. Armon, “Approaches to Increasing Surface Stress for Improving Signal -to-Noise Ratio of Microcantilever Sensors”. Anal. Chem. 2010, 82, 1634-1642. (PDF file)
• H. Zhang, X. Xu, H.-F. Ji, “Excitation-Wavelength-Dependent-Photoluminescence of Pyromellitic Diimide Nanowire Network”. Chem. Comm. 2010, 46, 1917-1919 (PDF file)

2009

• M. S. K. Mutyala, D. Bandhanadham, L. Pan, V. R. Pendyala, H.-F. Ji, “Mechanical and Electronic Approaches to Improve the Sensitivity of Microcantilever Sensors”, Acta Mechanica Sinica, 2009, 25, 1-12.  (PDF file)
• H. Gao, B. Chen, L. Z. Wu, C. H. Tung, H. –F. Ji, “ Ultrahydrophobicity of Polydimethylsiloxanes Based Multilayered Thin Films”, J. Nanotech.. 2009. doi:10.1155/2009/709748  (PDF file)

2008

• H. F. Ji, R. Majithia, X. Yang, X. Xu, K. More, “Self-Assembly of Perylenediimide and Naphthalenediimide Nanostructures on Glass Substrates through Deposition from the Gas Phase.”, J. Am. Chem. Soc. 2008, 130, 10056-10057. (PDF file)
• P. Kapa, P. Liu, Q. Chen, D. Morishetti, M. S. Mutyala, J. Fang, K. Varahramyan, H.-F. Ji “Moisture Measurement Using Porous Aluminum Oxide Coated Microcantilevers”. Sen. Actuat. B, Chem. 2008, 134, 390-395. (PDF file)
• X. Yang, X. Xu, H.-F. Ji, “Solvent Effect on the Self-Assembled Structure of an Amphiphilic Perylene Diimide Derivative”. J. Phys. Chem. B, 2008. 112, 7196-7202. (PDF file)
• Hongwei Du, Swapna Kondu, Hai-Feng Ji, Formation of Ultrathin Hydrogel Films on Microcantilever Devices Using Electrophoretic Deposition. Micro & Nano Lett. 2008, 3, 12-17. (PDF file)
• Y. Lu, H.-F. Ji, “Electric Field –Directed Assembly of Gold and Platinum Nanowires From an Electrolysis Process” Electrochemistry Communications, 2008, 10, 222-224. (PDF file)
• Hongyan Gao, Koutilya R. Buchapudi, Abraham Harms-Smyth, Marvin K. Schulte, Xiaohe Xu, and Hai-Feng Ji “Improved Surface Modification Approach for Micromechanical Sensors” Langmuir, 2008, 24, 345-349. (PDF file)
• Qi Chen, Ji Fang, Hai-Feng Ji, Micromachined SiO2 Microcantilever for High Sensitive Moisture Sensor" Microsystem Technologies, 2008, 14, 739-746. (PDF file)
• H.-F. Ji, Hongyan Gao, Koutilya, R. Buchapudi, Xin Yang, Xiaohe, Xu, Marvin K. Schulte “Microcantilever Biosensors Based on Conformational Change of Proteins”. The analyst, 2008, 132, 434-443. (PDF file)
• Q. Chen, J. Fang, H.-F. Ji, K. Varahramyan, “Isotropic etch for SiO2 microcantilever release with ICP system”, Microelectronics Engineering, 2008, 85, 500-507. (PDF file)
• Xiaolei Shi, Qi Chen, Ji Fang, Koday Varahramyan, and Hai-Feng Ji, “Al₂O₃-Coated Microcantilevers for Detection of Moisture at ppm Level”, Sen. Actua. B. 2008, 129, 241-245. (PDF file)

2007

• Q. Chen, J. Fang, H.-F. Ji, K. Varahramyan, “Fabrication of SiO2 Microcantilever Using Isotropic Etching with ICP”, IEEE Sensor Journal, 2007, 7, 1632-1638.
• Sreepriya Velanki, H. –F. Ji, T. Thundat, D. A. Blake, “Detection of Cd²⁺ Using Antibody Based Microcantilevers”. Ultramicroscopy, 2007, 107, 1123-1128. 
• Y. Lu, H.-F. Ji, “Fabrication of Microcoil/Microsprings for Novel Chemical and Biological Sensing”, Sen. Actua. B: Chem. 2007, 123, 937-941.
• Chandana Karnati, Hongwei Du, Hai-Feng Ji, X. Xu, Yuri Lvov, Wilfred Chen, Ashok Mulchandani “Organophosphrus Hydrolyase Multilayer Modified Microcantilevers for Organophosphorus Detection”, Biosensor Bioelectronics, 2007, 22, 2636-2642.
• H.-F. Ji “Chemical Specificity in Nanomechanical Sensors”, J. Solid State Phenomena. 2007, 121-123, 499-502.

2006

• X. Yan, K. Hill, H. Gao, H.-F. Ji “Surface Stress Changes Induced by Conformational Changes of Proteins”, Langmuir, 2006, 22, 11241-11244.
• Sreepriya Velanki, and Hai-feng Ji “Detection of Feline Coronavirus Using Microcantilever Sensors”, Meas. Sci. Technol. 2006, 17, 2964-2968.
• H.-F Ji, Y. Lu, H. Du, X. K. Xu, T. Thundat, “Spiral springs and microspiral springs for chemical and biological sensing” Appl. Phys. Lett. 2006, 88, 063504/1-063504/3.
• V. Chivukula, M. Wang, X. Shi, H.-F. Ji, “Simulation and Fabrication of Piezoresistive Microbridge for Chem/Biosensors”, J. Micromech. Microeng. 2006, 16, 692-698.
• X. Yan, H.-F. Ji, T. Thundat, “Microcantilever Biosensing”, Current Analytical Chemistry,  2006, 2, 297-307
• Y. Tang, X. Xu, J. Fang, Y. Liang, H.-F. Ji “Perfluorocarbon Nanofilament Array Formation on SiO₂ and the Hyperhydrophobicity of the Surface” IEEE Transaction on Nanotechnology, 2006, 5(4), 415-419.
• H.-F. Ji, Y. Yang, X. Xu, G. M. Brown, “A Calixarene Based Fluorescent Sr²⁺ and Ca²⁺ probe”, Org. Biomol. Chem. 2006, 4, 770-772.
• X. Yan, X. Shi, K. Hill, H.-F. Ji “Microcantilevers Modified by Horseradish Intercalated Nano-Assembly for Hydrogen Peroxide Detection”, Anal. Sci. 2006, 22, 205-208
• J. S. Mao, S. Kondu, H. F. Ji, M. J. McShane, “Study of the pH-sensitivity of chitosan/gelatin hydrogel in neutral pH range by microcantilever method” Biotechnology and Bioengineering, 2006, 95(3), 333-341
• X.-H. Xu, X.-G. Fu, L.-Z. Wu, L.-P. Zhang, C.-H. Tung  H.-F. Ji, K. S. Schanze, R.-Q. Zhang, “Intramolecular Triplet Energy Transfer in Donor-Acceptor Molecules Linked by Flexible-Rigid Block Bridge”, Chem. Eur. J., 2006, 12, 5238-5245.
• V. Chivukula, M. Wang, H.-F. Ji, A. Khaliq, J. Fang, K. Varahramyan. “Simulation of SiO₂ –Based Piezoresistive Microcantilevers”, Sensor & Actuators, A, 2006, 125(2), 526-533.

2005

• H.-F. Ji, Y. Zhang, V. V. Purushotham, S. Kondu, B. Ramuchandran, T. Thundat, D. T. Haynie, “1,6-hexanedithiol monolayers as a receptor for specific recognition of alkylmercury”, Analyst, 2005, 130, 1577 – 1579
• H. –F. Ji, X. Yan, M. McShane “Experimental and Theoretical Aspects of Glucose Measurement Using a Microcantilever Modified by Enzyme-Containing Polyacrylamide” Diabetes Technology & Therapeutics, 2005, 7(6), 986-995
• X. Yan, X. K. Xu, and H.-F. Ji “Glucose Oxidase Multilayer Modified Microcantilever for Glucose Measurement”, Anal. Chem. 2005, 77(19), 6197-6204
• Z. H. Shaik, H.-F. Ji, “Protecting Conductive Polymer Wire From Oxidation Using an air-impermeable Polyisobutylene Coating” Thin Solid Films, 2005, 488/1-2, 149-152.
• L. A. Pinnaduwage, H.-F. Ji, and T. Thundat, “Moore’s Law in Homeland Defense: A integrated sensors platform based on silicon microcantilevers”. Invited review paper. IEEE sensors, 2005, 5, 774-785
• Y. Tang, H.-F. Ji, “Cysteine monolayer modified microcantilevers for impulse monitoring”. Instrumentation Science & Technology, 2005, 33, 131-136
• W. Zhou, A. Khaliq, Y. Tang, H.-F. Ji, R. R. Selmic “Simulation and Design of Piezoelectric Microcantilever Chemical Sensors” Sensors and Actuators, A, 2005, 125,(1), 69-75
• D. Kommireddy, J. Shi, X. Yan, H. Ji, Y. Lvov, “Electrostatic Layer-by-Layer Nano-Assembly: Films, Cantilevers, Micropatterns and Nanocapsules” Invited paper. Proc. Of SPIE, 2005, vol. 5592, 120-131.

2004

• X. Yan, Y. Tang, H.-F. Ji, Y. Lvov, T. Thundat “Detection of Organophosphates Using an Acetyl cholinesterase (AChE) Coated Microcantilever” Instrument Science & Technology. 2004, 32, 175-183
• X. Yan, H.-F. Ji, Y. Lvov, “Modification of microcantilevers using Layer-by-Layer nanoassembly film for glucose  measurement”. Chemical Physical Letters, 2004, 396, 34-37
• H. –F. Ji, Y. Feng, X. Xu, V. Purushotham, T. Thundat, G. M. Brown, “Photon-Driven Nanomechanical Cyclic Motion”, Chem. Commun. 2004, 22, 2532-2533
• Xiaodong Yan, Jing Zhang, Hai-Feng Ji and T. Thundat “Molecular Recognition of Biowarfare Agents Using Micromechanical Sensors”, invited review paper, Expert Review of Molecular Diagnostics, 2004, 4(6), 859-866,.
• Yanjun Tang, X. Xu, Haifeng Ji, G. M. Brown, T. Thundat, “Detection of Femtomolar Concentration of HF Using an SiO₂ Microcantilever” Anal. Chem. 2004, 76(9), 2478-2481
• J. Zhang, H.-F. Ji, “An Anti E. Coli O157:H7 Antibody-Immobilized Microcantilever for the Detection of Escherichia Coli (E. Coli)”, Anal. Sci., 2004, 20, 585-587
• Yifei Zhang, Srinivasan P Venkatachalan, Hao Xu, Xiaohe Xu, Prasad Joshi, Hai-Feng Ji, Marvin Schulte “Micromechanical Measurement of Membrane Receptor Binding for Label-free Drug Discovery”  Biosensors & Bioelectronics, 2004, 19, 1473-1478
• K. Liu, H. –F. Ji, “Detection of Pb2+ Using a hydrogel swelling Microcantilever sensor”, Anal. Sci. 2004, 20, 9-11
• Y. Zhang, H. –F. Ji, D. Snow, G. M. Brown, R. Sterling, “A pH Sensor Based on a Microcantilever Coated with Intelligent Hydrogel”, Instrument Science & Technology. 2004, 32(4), 361-369
• Yanjun Tang, Ji Fang, Xiaodong Yan, Hai-Feng Ji, “Fabrication and Characterization of SiO₂ Microcantilever for Microsensor Application”, Sensor and Actuators, B  2004, 97, 109-113

2003

• Y. Zhang, H. –F. Ji, G. Brown, T. Thundat, “Detection of CrO₄^2- Using a Hydrogel Swelling Microcantilever Sensor”  Anal. Chem. 2003, 75, 4773-4777
• X. Yan, Y. Lvov, H. –F. Ji, A. Singh, T. Thundat,  “A General Microcantilever Surface Modification method using a Multilayer for Biospecific Recognition”, Organic and Biomolecular Chemsitry, 2003, 1(3),  460-462.
• Y. Yang, H. –F. Ji, T. Thundat, “Nerve Agents Detection Using a Cu2+/L-Cysteine Bilayer-Coated Microcantilever”, J. Amer. Chem. Soc. 2003, 125, 1124-1125.

2002

• A. C. Stephan, E. L. Finot, H. –F. Ji, L. A. Pinnaduwage, T. G. Thundat, “Micromechanical Measurement of Active Sites on Silicon Nitride Using Free Surface Energy”,  Ultramicroscopy, 2002, 91(1-4), 1-8.
• X. Xu, T. G. Thundat and G. M. Brown, H.-F. Ji, “Detection of Hg²⁺ using Microcantilever sensors”, Anal. Chem., 2002, 74(15), 3611-3615
• H. Xu, X. Xu, R. Dabestani, and G. M. Brown, “Supramolecular Fluorescent Probes for the Detection of Mixed Alkali Ions that Mimic the Function of Integrated Logic Gate”,  J. Chem. Soc. Perkin Trans. 2, 2002, (3), 636-643
• H.-F. Ji and T. G. Thundat, “In situ detection of calcium ions with chemically modified microcantilevers”, Biosensors & Bioelectronics. 2002  17(4), 337-343

2001

• X. Xu, H. Xu and H.-F. Ji, “New Fluorescent Probes for the Detection of Mixed Sodium and Potassium Metal Ions”, Chem. Commun., 2001, (20), 2092-2093
• H.-F. Ji, H. Xu and X. Xu, “High Concentration Leveling Effect on 1:2 Stoichiometry Complexation between 1,3-Alternate Calix[4]-bis-benzocrown-6 and Cs⁺ ”, Chem. Phys. Lett., 2001, 343, 325-331
• H.-F. Ji, X. Xu, C.-H. Tung, “Chromophore End-Labelled Long Chain Perfluoropolyether as Probes to Study the Formation of Aggregates in Aqueous Organic Solvent and Their Asymmetrical coaggregation with Hydrocarbons”, J. Photochem. Photobio. A, Chemistry, 2001, 144, 179-184
• G. Wu, H. –F. Ji, K. Hansen, T. Thundat, R. Datar, R. Cote, M. F. Hagan, A. K. Chakraborty, and A. Majumdar “Origin of Nanomechanical Cantilever Motion Generated from Biolecular Interactions. “ Proc. Natl. Acad. Sci. 2001, 98, 1560-1564
• K. M. Hansen, H.-F. Ji, G. Wu, R. Datar, R. Cote, A. Majumdar, T. Thundat, “Cantilever-based optical deflection assay for discrimination of DNA single-nucleotide mismatches” Anal. Chem., 2001, 73(7), 1567-1571
• H. F. Ji, T. Thundat, R. Dabestani, G. M. Brown, P. F. Britt, and P. Bonnesson “Ultrasensitive Detection of CrO₄^2- Using a Microcantilever sensor”, Anal. Chem. 2001, 73(7), 1572-1576
• H.-F Ji, R. Dabestani, and G. M. Brown, R. L. Hettich, “Synthesis and Sensing Behavior of Cyanoanthracene Modified 1,3-Alternate Calix[4]-benzocrown-6: A New Class of Cs⁺ Selective Optical Sensors”, J. Chem. Soc., Perkin Trans. II, 2001, 585-591.
• H.-F. Ji, K. M. Hansen, Z. Hu, Thundat, T, “Detection pH variation using modified microcantilever sensors”, Sensor and Actuators. B. Chem., 2001, B72(3), 233-238.
• Hubner, J.P., Carroll, B.F., Schanze, K.S., Ji, H.F., and Holden, M., "Temperature- and Pressure-Sensitive Paint Measurements in Short-Duration Hypersonic Flow," AIAA Journal, 2001, 39, 654-659

2000

• H. -F. Ji, R. Dabestani, G. M. Brown, and R. A. Sachleben, “A new highly selective calix[4]-crown-6 fluorescent cesium probe”, Chem. Commun. 2000, 833-834
• H. –F. Ji; Shen, Y.; Hubner, J. P.; Carroll, B. F., Schmehl, R. H.; Simon, J. H. and Schanze, K. S. "A Temperature-Independent Pressure-Sensitive Paint Based on a Bichromophoric Luminophore" Applied Spectroscopy 2000, 54, 856-863
• H. F. Ji, R. Dabestani, E. Finot, T. Thundat, G. M. Brown and P. F. Britt, “A Noval Self-Assembled Monolayer Coated Microcantilever for Low Level Cesium Detection”, Chem. Commun., 2000, 457-458
• Hubner, J. P., Carroll, B. F., Schanze K. S., and Ji, H. F., “Pressure-Sensitive Paint Measurements in a Shock Tube,” Experiments in Fluids, 2000, pp. 21-28.
• H. -F. Ji, R. Dabestani, G. M. Brown, “A Supramolecular Fluorescent Probe Activated by Protons to Detect Cesium and Potassium Ions, Mimics the Function of a Logic Gate”,  J. Am. Chem. Soc. 2000, 122, 9306-9307
• K. M. Hansen, G. Wu, H.-F. Ji, T. Thundat, R. Datar, R. Cote, A. Majumdar,  “Nanomechanical detection of biomolecular interactions.    Proceedings - Electrochemical Society, 2000,  2000-19 (Microfabricated Systems and MEMS V),  200-207.

1999

• H.-F. Ji, R. Dabestani, R. L. Hettich, and G. M. Brown, “Optical Sensing of Cesium Using 1,3-alternate calix[4]-mono- and Di(anthrylmethyl)aza-crown-6”.    Photochem. Photobio., 1999, 70(6), 882-886.
• H.-F Ji, G. M. Brown, and R. Dabestani, “Calix[4]arene-based Cs⁺ Selective Optical Sensors”,  Chem. Commun.,1999,  7, 609-610
• T. Thundat, E. Finot, H.-F. Ji, R. Dabestani, P.F. Britt, P. V. Bonnesen, G. M. Brown, R. J. Warmack, “Highly Selective Microcantilever Sensor for Cesium Ion Detection.”, Proc. –Electrochem. Soc., 1999, 99-23, 314-319.
• H. –F. Ji, R. Dabestani, G.M. Brown, R. L. Hettich, “Spacer Length Effect on the Photoinduced Electron Transfer Fluorescent Probe for the Alkali Metal Ions.”, Photochem. Photobio,.1999, 69, 513-516.

1998

• K. S. Schanze, Lucian A. Lucia, M. Cooper, K. A. Walters, H.-F. Ji and O. Sabina, “ Intramolecular Energy Transfer to trans-Stilbene”,   J . Phys. Chem.,1998, 102, 5577-5584

1997

• Hubner, J. P., Carroll, B. F., Schanze, K. S., and Ji, H. F., "Pressure-Sensitive Paint Measurements in a Shock Tube," 17th ICIASF Record, 1997, pp. 30-39.
• C.-H. Tung, H. -F. Ji, "A Novel Host-Guest Molecules p-[1-(4-hydroxyphenyl)-1-methylethyl]calix[8]. Synthesis and Complexation Properties in Non-aqueous Polar Solution",   J. Chem. Soc. Perkin Trans.II. 1997, 185-188

1996

• Y.-Z. Wang, H.-F. Ji, C.-H. Tung, G. C. Yue, "Interaction of Polyelectrolyte with Fluorocarbon Surfactant in Aqueous Solution", Chin. Chem. Lett. 1996, 7, 951-953
• H.-F. Ji, Chen-Ho Tung, "Fluorescence and Photodimerization of a Calix[4]arene-Based 2-Naphthoate”, Photograph. Sci. Photochem. 1996, 14, 289-292

1995

• C.-H. Tung, H.-F. Ji, "Hydrophobic Effects on Photochemical and Photo-physical Processes. Evidence for Aggregation of Perfluorocarbon in Aqueous Organic Solvents",  J. Chem. Soc., Faraday Trans., 1995, 91(17), 2761-2765.
• C.-H. Tung, H.-F. Ji,"Aggragation Behavior of Mixed Fluorocarbon and Hydrocarbon Molecules in Aqueous Organic Solvents. Nonideality and Ideality of Mixing", J. Phys. Chem.,1995, 99, 8311-8316.
• C.-H. Tung, H.-F. Ji, "Evidence for Aggragate Formation of long Chain Per-fluorocarbon in Aqueous Organic Solvents: Excimer Emission and Enengy Transfer", Chin. Chem. Lett., 1995, 6(1), 31-34.

Book Chapters

• “Photophysical and Photochemical Applications of Calixarene”, in Recent Research Developments in Photochemistry and Photobiology, ISBN: 81-7895-053-7. Transworld Research Network, 2002, 6, 121-139
• H. –F. Ji, S. Sreepriya, X. Yan, V. Purushotham, Z. Haque, Y. Tang, “Microcantilever Chemical/bio Sensors” in “Recent Research Development in Chemistry”, 2004, 2, 1-27. Publisher: Research Signpost.
• “Environmental Monitoring Using Microcantilever Sensors” in “Subsurface Contamination Remediation”, Chapter 12. Editors: Edgar Berkey and Tiffany Zachry. 2004
• “Molecular Logic Gates”, in Micromanufacturing and Nanotechnology, ISBN: 3-540-25377-7. Spinger, 2005. 275-298