Abstract

Immunoassays for detection of bacterial pathogens rely on the selectivity and stability of bio-recognition elements such as antibodies tethered to sensor surfaces. The search for novel surfaces that improve the stability of biomolecules and assay performance has been pursued for a long time. However, the anticipated improvements in stability have not been realized in practice under physiological conditions because the surface functionalization layers on commonly used substrates, silica and gold, are themselves unstable on time scales of days. In this paper, we show that covalent linking of antibodies to diamond surfaces leads to substantial improvements in biological activity of proteins as measured by the ability to selectively capture cells of the pathogenic bacterium Escherichia coli O157:H7 even after exposure to buffer solutions at 37 °C for extended periods of time, approaching 2 weeks. Our results from ELISA, XPS, fluorescence microscopy, and MD simulations suggest that by using highly stable surface chemistry and controlling the nanoscale organization of the antibodies on the surface, it is possible to achieve significant improvements in biological activity and stability. Our findings can be easily extended to functionalization of micro and nanodimensional sensors and structures of biomedical diagnostic and therapeutic interest.

Original languageEnglish (US)
Pages (from-to)1040-1050
Number of pages11
JournalAdvanced Functional Materials
Volume21
Issue number6
DOIs
StatePublished - Mar 22 2011

Keywords

  • biofunctionalized diamond
  • diamond biosensors
  • diamond thin films
  • proteins
  • ultrananocrystalline diamond

ASJC Scopus subject areas

  • Biomaterials
  • Electrochemistry
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Fingerprint Dive into the research topics of 'Control of nanoscale environment to improve stability of immobilized proteins on diamond surfaces'. Together they form a unique fingerprint.

  • Cite this