PECVD coatings for functionalization of point-of-care biosensor surfaces

Abstract

In early stage disease diagnosis, an accurate and reliable measurement of low concentrations of specific biomarkers is a key need. The detection technique requires the reaction of an antibody, which is generally covalently bound to the biosensor platform, with its antigen. The application of Zeonor®, a cyclo olefin copolymer (COP) with very low autofluorescence, good optical properties and high precision molding characteristics, as a biosensor platform has been demonstrated recently. Highly reproducible, industrial scale surface chemical modification of the COP plastic for covalent attachment of the biomolecules for specific recognition of the target, together with low non specific binding of other proteins that may be present in the sample is a key challenge. In this work, the applicability of plasma enhanced chemical vapor deposition (PECVD) process has been demonstrated by depositing varying surface functionalities including amines, carboxylic, mercapto, epoxy and polyethylene glycol functionalities.The plasma functionalized coatings thus created possess both reactive and repellent sites on the biosensor chip, allowing the chip to be configured either for fluorescence or light scattering-based detection or for label-free surface plasmon resonance detection techniques. The versatility of the gas phase deposition process for building sequential chemistries on low cost and disposable plastic chips is presented in detail. * Corresponding Author: Vladimir.gubala@dcu.ie , Ph: +35317006337 IntroductionWith parameters. The effect of ion bombardment on the growing film and the plasma electron density are crucial and could lead to dissociation of functional groups in the plasma as well as on the growing film. In this article, synthetic approaches for modification of COP substrates with -NH 2 and -SH functional groups will be discussed. Perhaps more importantly, we will also provide a review on the analytical tools used to assess the quality of the prepared films. For a design of sensitive bioassay device, it is critical to understand interaction forces in real systems, and how these relate on the one hand to the surface composition and chemistry, and on the other hand to the specificity, sensitivity and resistance to non-specific binding. 2.Materials and methods Plasma Enhanced Chemical Vapor DepositionThe vacuum chamber is an aluminum based container. The pressure in the chamber was measured using a Granville-Phillips gauge. An Edwards EH mechanical booster pump backed by an Edwards E1M40 rotary pump was used to pump down the chamber.The rotary pump was connected through a port at the bottom of the chamber.The powered electrode, 24cm x 21cm plate with a 6cm diameter with a hole in the middle, was placed slightly below the top of the chamber and the chamber wall was grounded. The powered electrode is cooled with running water. Also a 24cm X 21cm X 1.2cm electrically isolated, water cooled hollow metallic setup placed 10 cm away from the powered electrode is used as the substrate holder. The powered electrod...

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Immobilization of Antibodies and Enzymes on 3-Aminopropyltriethoxysilane-Functionalized Bioanalytical Platforms for Biosensors and Diagnostics

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Plasma-Enhanced Chemical Vapor Deposition: Where we are and the Outlook for the Future

“…Multiple studies have used PECVD for the deposition of various end-groups such as amines, carboxylic, mercapto, epoxy, and polyethylene glycol to address the problem of nonspecific binding of single-stranded DNA or other proteins of interest. Parameters such as higher RF power lead to increase in thickness of the film due to increased rate of deposition [140,141]. Monomers such as amino silanes, allylamine, and allyl organophosphates have been commonly used for the deposition of thin films with reactive functional groups [58,127].…”