Improving the sensitivity of immunoassays with PEG-COOH-like film prepared by plasma-based technique

• Published in: Journal of biomedical materials research. Part A Vol. 100A; no. 1; pp. 230 - 235
• Main Authors: O'Mahony, Christy Charlton, Gubala, Vladimir, Gandhiraman, Ram Prasad, Daniels, Stephen, Yuk, Jong Seol, MacCraith, Brian D., Williams, David E.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.01.2012; Wiley-Blackwell
• Subjects: Acrylates - chemistry; Antibodies - immunology; Biological and medical sciences; biosensor; Fluorescence; Humans; immunoassay; Immunoassay - methods; Immunosorbents; Investigative techniques, diagnostic techniques (general aspects); Materials Testing - methods; Medical sciences; Miscellaneous. Technology; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; plasma enhanced chemical vapor deposition; Plasma Gases - chemistry; Polyethylene Glycols - chemistry; Sensitivity and Specificity; surface chemistry; Surface Properties; Water; Human; surface chemistry; plasma enhanced chemical vapor deposition; Immunological method; immunoassay; Ethylene oxide polymer; Sensitivity; Cyclic ether polymer; Functionalization; Immunosorbent; Biosensor; Surface properties; Biomaterial; Technique; Biomedical engineering
• ISSN: 1549-3296; 1552-4965; 1552-4965
• DOI: 10.1002/jbm.a.33268

Herein we report on a preparation and performance of stable, hydrophilic and biocompatible polymeric material suitable for functionalization of disposable substrates used in biosensors. This new material features COOH surface groups cross‐linked with ethylene glycol molecules and was prepared in situ on disposable, plastic substrate by high‐throughput and environmentally friendly technique called plasma‐enhanced chemical vapor deposition (PECVD). The film is grafted to the plasma activated plastic by sequential deposition of tetraethylorthosilicate, forming a bonding layer, and mixed vapors of acrylic acid and diethyleneglycol dimethylether (AA/PEG) that provide the desired functional groups forming a sensing, contact layer. A superior performance of the AA/PEG coating as suitable material for substrates in biomedical devices was demonstrated in a model fluorescence linked immunosorbent assay. The results were compared with other commonly used surface materials prepared by wet chemistry methods. The unique characteristic of the AA/PEG film is that the immunoassay can be executed without the need for a blocking step, typically using albumins, without negative consequences on the bioassay results. In fact, the superior quality of the materials modified with AA/PEG film was highlighted by improving the sensitivity of an immunoassay by two orders of magnitude when compared with substrates prepared by standard surface chemistry methods. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.