One step immobilization of peptides and proteins by using modified parylene with formyl groups.

One-step immobilization method for peptides and proteins is developed by using modified parylene film with formyl groups which is suitable for microplate-based immunoassay and SPR biosensor application. The immobilization of peptides and proteins is achieved through the covalent bonding of the formyl group with the primary amine groups of peptides and proteins, which no additional activation step is required. In this work, the immobilization efficiency of parylene-H is estimated in comparison with parylene-A and physical adsorption, using biotinylated-cyclic citrullinated peptide (biotinylated-CCP), human chorionic gonadotropin (hCG) and horseradish peroxidase (HRP) as model proteins. The applicability of parylene-H film to SPR biosensor is demonstrated by estimating the detection range and sensitivity of SPR biosensor at various thicknesses. The immobilization efficiency of parylene-H film for SPR biosensor was compared with physical adsorption by using HRP as a model protein.

Parylene-A coated microplate for covalent immobilization of proteins and peptides.

Various types of microplates made of polystyrene have been widely used for immunoassays. A new microplate suitable for the covalent immobilization of proteins and peptides was developed by thermal deposition of amino-modified parylene (parylene-A) on the microplate. The primary amine groups of the parylene-A was exploited for the covalent coupling of proteins and peptides. The optical transmittance at the wavelength of 400-500 nm was estimated to be suitable for the application to immunoassays. The immobilization efficiency of the parylene-A coated microplate was demonstrated to be far improved in comparison to the conventional microplate by using horseradish peroxidase (HRP), anti-HRP antibody and a peptide with 9-residues as model biomolecules.