Xiyun Guan photo
211 Chemistry

Nanopore stochastic sensing has attracted substantial interest as a label-free technique to measure single molecules by taking advantage of the ionic current modulations produced by the movement of target analytes in a single nano-scale sized pore. A major bottleneck of utilizing nanopore sensors for practical applications is the rapid transport of target analytes through the pore since current recording techniques do not always accurately detect these rapid events. Guan's research efforts advance nanopore technology as a versatile tool for exploring various new applications, especially in medical diagnosis, homeland security, pharmaceutical screening, and environmental monitoring.


  • Development of nanopore single-molecule detection technique for applications in biotechnology;
    • Biomarker detection
    • DNA methylation mapping
    • Biosensor design
    • Molecular transport
    • Drug discovery and controlled drug delivery
  • (Bio-)material development for use in sensors, drug delivery and energy applications;
  • Direct and in-situ environmental monitoring and medical diagnosis.

Postdoc positions are available immediately to develop nanopore sensors for various applications. The positions, which are supported by NIH and/or NSF funds, will be one year but may be renewed annually at the discretion of the University based on work performance, and fund availability. Salary will be commensurate to experience. To Apply, please send a cover letter, curriculum vitae, and contact information for 2-3 references to Richard Guan (xgpc2@missouri.edu).

Select Publications
  1. Guan, X.; Gu, L. Q.; Cheley, S.; Braha, O.; Bayley, H. Stochastic sensing of TNT with a genetically engineered pore. ChemBioChem, 2005, 6, 1875-1881.
  2. Kang, X. F.; Cheley, S.; Guan, X.; Bayley, H. Stochastic detection of enantiomers. J. Am. Chem. Soc. 2006, 128, 10684-10685.
  3. Zhao, Q.; Wang, D.; Jayawardhana, D. A.; Guan, X. Stochastic sensing of biomolecules in a nanopore sensor array. Nanotechnology 2008, 19, 505504.
  4. ​​​​​​​Jayawardhana, D. A.; Crank, J. A.; Zhao, Q.; Armstrong, D. W.; Guan X. Nanopore stochastic detection of a liquid explosive component and sensitizers using boromycin and an ionic liquid supporting electrolyte. Anal. Chem. 2009, 81, 460-464.
  5. ​​​​​​​Zhao, Q.; Jayawardhana, D. A.; Wang, D.; Guan, X. Study of peptide transport through engineered protein channels. J. Phys. Chem. B 2009, 113, 3572-3578.
  6. ​​​​​​​Zhao, Q.; Wang, D.; Jayawardhana, D. A.; de Zoysa, R. S.; Guan, X. Real-time monitoring of peptide cleavage using a nanopore probe. J. Am. Chem. Soc. 2009, 131, 6324-6325.
  7. ​​​​​​​Jayawardhana, D. A.; Sengupta, M.; Krishantha, D. M. M.; Gupta, J.; Armstrong, D. W.; Guan, X. A chemical-induced and pH-mediated molecular switch. Anal. Chem., 2011, 83, 7692-7697.
  8. ​​​​​​​Wang, G.; Wang, L.; Han, Y.; Zhou, S.; Guan, X. Nanopore stochastic detection: Diversity, sensitivity, and beyond. Acc. Chem. Res. 2013, 46, 2867-2877.
  9. ​​​​​​​Wang, G.; Wang, L.; Han, Y.; Zhou, S.; Guan, X. Nanopore detection of copper ions using a polyhistidine probe. Biosens. Bioelectron. 2014, 53, 453-458.
  10. ​​​​​​​Wang, L.; Han, Y.; Zhou, S.; Wang, G.; Guan, X. Nanopore biosensor for label-free and real-time detection of anthrax lethal factor. ACS Appl. Mater. Interfaces 2014, 6, 7334- 7339.
  11. ​​​​​​​Wang, L.; Han, Y.; Zhou, S.; Wang, G.; Guan, X. Real-time label-free measurement of HIV-1 protease activity by nanopore analysis. Biosens. Bioelectron. 2014, 62, 158-162.
  12. ​​​​​​​Zhou, S.; Wang, L.; Chen, X.; Guan, X. Label-free nanopore single-molecule measurement of trypsin activity. ACS Sens. 2016, 1, 607-613.
  13. ​​​​​​​Roozbahani, G. M.; Chen, X.; Zhang, Y.; Xie, R.; Ma, R.; Li, D.; Li, H.; Guan, X. Peptide-mediated nanopore detection of uranyl ions in aqueous media. ACS Sens. 2017, 2, 703-709.
  14. ​​​​​​​Chen, X.; Roozbahani, G. M.; Ye, Z.; Zhang, Y.; Ma, R.; Xiang, J.; Guan, X. Label-free detection of DNA mutations by nanopore analysis. ACS Appl. Mater. Interfaces 2018, 10, 11519-11528.
  15. ​​​​​​​Roozbahani, G. M.; Chen, X.; Zhang, Y.; Juarez, O.; Li, D.; Guan, X. Computation- assisted nanopore detection of thorium ions. Anal. Chem. 2018, 90, 5938-5944.
  16. ​​​​​​​Zhang, Y.; Chen, X.; Roozbahani, G. M.; Guan, X. Graphene oxide-based biosensor for rapid and sensitive detection of HIV-1 protease. Anal. Bioanal. Chem. 2018, 410, 6177- 6185.
  17. ​​​​​​​Wang, L.; Chen, X.; Zhou, S.; Roozbahani, G. M.; Zhang, Y.; Wang, D.; Guan, X. Displacement chemistry-based nanopore analysis of nucleic acids in complicated matrices. Chem Commun. 2018, 54, 13977-13980.
  18. ​​​​​​​Roozbahani, G. M.; Chen, X.; Zhang, Y.; Wang, L.; Guan, X. Nanopore detection of metal ions: Current status and future perspectives. Small Methods 2020, 4, 2000266.
  19. Zhang, Y.; Chen, X.; Wang, C.; Roozbahani, G. M.; Chang, H. C.; Guan, X. Chemically functionalized conical PET nanopore for protein detection at the single-molecule level. Biosens. Bioelectron. 2020, 165, 112289.
  20. ​​​​​​​Zhang, Y.; Chen, X.; Yuan, S.; Wang, L.; Guan, X. Joint entropy-assisted graphene oxide-based multiplexing biosensing platform for simultaneous detection of multiple proteases. Anal. Chem. 2020, 92, 15042-15049.
  21. ​​​​​​​Chen, X.; Zhang, Y.; Guan, X. Simultaneous detection of multiple proteases using a non- array nanopore platform. Nanoscale 2021, 13, 13658-13664.
  22. ​​​​​​​Chen, X.; Zhang, Y.; Arora, P.; Guan, X. Nanopore stochastic sensing based on non- covalent interactions. Anal. Chem. 2021, 93, 10974-10981.
  23. ​​​​​​​Wang, H.; Huang, W.; Wang, Y.; Li, W.; Liu, Q.; Yin, B.; Liang, L.; Wang, D.; Guan, X.; Wang, L. Enzyme hinders HIV-1 Tat viral transport and real-time measured with nanopores. ACS Sens. 2021, 6, 3781-3788.
  24. ​​​​​​​Zhang, Y.; Chen, X.; Wang, C.; Chang, H.-C.; Guan, X. Nanoparticle-assisted detection of nucleic acids in a polymeric nanopore with a large pore size. Biosens. Bioelectron. 2022, 196, 113697.
  25. ​​​​​​​Wang, L.; Wang, H.; Chen, X.; Zhou, S.; Wang, Y.; Guan, X. Chemistry solutions to facilitate nanopore detection and analysis. Biosens. Bioelectron. 2022, 114448.
  26. ​​​​​​​Li, W.; Wang, Y.; Xiao, Y.; Li, M.; Liu, Q.; Liang, L.; Xie, W.; Wang, D.; Guan, X.; Wang, L. Simultaneous dual-site identification of 5mC/8oG in DNA triplex using a nanopore sensor. ACS Appl. Mater. Interfaces 2022, 14, 32948–32959.
  27. Li, W.; Wang, Y.; Xiao, Y.; Li, M.; Liu, Q.; Liang, L.; Xie, W.; Wang, D.; Guan, X.; Wang, L. Nanopore discrimination and sensitive plasma detection of multiple natriuretic peptides: The representative biomarker of human heart failure. Biosens. Bioelectron. 2023, 231, 115299.
  28. Chen, X.; Zhou, S.; Wang, Y.; Zheng, L.; Guan, S.; Wang, D.; Wang, L.; Guan, X. Nanopore single-molecule analysis of biomarkers: Providing possible clues to disease diagnosis. TrAC Trends in Analytical Chemistry 2023, 117060.