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Biosensors: Control of Nanoscale Environment to Improve Stability of Immobilized Proteins on Diamond Surfaces (Adv. Funct. Mater. 6/2011)
Author(s) -
Radadia Adarsh D.,
Stavis Courtney J.,
Carr Rogan,
Zeng Hongjun,
King William P.,
Carlisle John A.,
Aksimentiev Aleksei,
Hamers Robert J.,
Bashir Rashid
Publication year - 2011
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201190011
Subject(s) - surface modification , biomolecule , biosensor , materials science , nanoscopic scale , nanotechnology , diamond , biointerface , covalent bond , fluorescence microscope , x ray photoelectron spectroscopy , fluorescence , chemical engineering , chemistry , organic chemistry , optics , physics , engineering , composite material
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 ºC 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.