Strong and selective adsorption of lysozyme on graphene oxide

Shanghao Li, Jerome J. Mulloor, Lingyu Wang, Yiwen Ji, Catherine J. Mulloor, Miodrag Micic, Jhony Orbulescu, Roger M. Leblanc

Research output: Contribution to journalArticlepeer-review

83 Scopus citations


Biosensing methods and devices using graphene oxide (GO) have recently been explored for detection and quantification of specific biomolecules from body fluid samples, such as saliva, milk, urine, and serum. For a practical diagnostics application, any sensing system must show an absence of nonselective detection of abundant proteins in the fluid matrix. Because lysozyme is an abundant protein in these body fluids (e.g., around 21.4 and 7 μg/mL of lysozyme is found in human milk and saliva from healthy individuals, and more than 15 or even 100 μg/mL in patients suffering from leukemia, renal disease, and sarcoidosis), it may interfere with detections and quantification if it has strong interaction with GO. Therefore, one fundamental question that needs to be addressed before any development of GO based diagnostics method is how GO interacts with lysozyme. In this study, GO has demonstrated a strong interaction with lysozyme. This interaction is so strong that we are able to subsequently eliminate and separate lysozyme from aqueous solution onto the surface of GO. Furthermore, the strong electrostatic interaction also renders the selective adsorption of lysozyme on GO from a mixture of binary and ternary proteins. This selectivity is confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), fluorescence spectroscopy, and UV-vis absorption spectroscopy.

Original languageEnglish (US)
Pages (from-to)5704-5712
Number of pages9
JournalACS Applied Materials and Interfaces
Issue number8
StatePublished - Apr 23 2014


  • fluorescence quenching
  • graphene oxide
  • interaction
  • lysozyme
  • selective adsorption

ASJC Scopus subject areas

  • Materials Science(all)


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