Comparison of Protein Surface Attachment on Untreated and Plasma Immersion Ion Implantation Treated Polystyrene: Protein Islands and Carpet

Abstract

Surface attachment of the enzyme horseradish peroxidase (HRP) was studied on untreated and ion beam implanted polystyrene (PS) films. The PS films of 100 nm thickness on a silicon wafer were treated using the plasma immersion ion implantation (PIII) technique, with argon ions of energy 20 keV and fluences of up to 2 x 10(16) ions/cm2. Differential transmittance Fourier transform infrared (FTIR) spectra confirmed the presence of proteins on the PS surfaces by detection of the amide A, I, and II protein vibrations. Spectroscopic ellipsometry over the UV-vis spectral region provided the optical constants and thickness of the protein layer, while tapping mode atomic force microscopy (AFM) was used to image the protein distribution on the surface. The combination of AFM, ellipsometry, and FTIR analysis showed that, on the untreated PS surface, HRP formed islands 8 nm in height and 30 nm in lateral size, covering approximately 27% of the PS surface. After PIII modification of the PS surface, the protein covered 100% of the surface area.

Evaluation of corrosion resistance and cytocompatibility of graded metal carbon film on Ti and NiTi prepared by hybrid cathodic arc/glow discharge plasma-assisted chemical vapor deposition

“…Similar effects were reported by Nosworthy et al [46]. Covalent immobilization of enzyme horseradish peroxidase with 100% protein coverage on the plasma-modified surface was observed by Gan et al [74] and rapid covalent immobilization of protein molecules on the plasma-modified surface with a larger cell density was observed by Tran et al [60]. Ho et al [75] also observed improved binding of protein molecules with retained conformation and Waterhouse et al [3] observed robust covalent immobilization of protein molecules having low thrombogenicity on the plasma-modified stainless steel coronary stent.…”

Graded metal carbon protein binding films prepared by hybrid cathodic arc — Glow discharge plasma assisted chemical vapor deposition

“…Rapid covalent binding of protein molecules with a higher cell density on the plasma modified surface was observed by Tran et al [42]. Gan et al [47] observed covalent binding of protein molecules with 100 % coverage on plasma treated surfaces. Waterhouse et al [15] observed good covalent binding of protein molecules with low thrombogenicity on plasma treated stainless steel coronary stents.…”

Covalent Attachment and Bioactivity of Horseradish Peroxidase on Plasma‐Polymerized Hexane Coatings

“…It interferes with even the strongest interactions involved in physisorption and as such will remove protein that is not covalently bonded to the surface. The SDS cleaning procedure is widely accepted as a method to test whether proteins are covalently attached to surfaces or not 9, 10…”

“…Enhanced attachment of bioactive enzymes (horseradish peroxidase, soybean peroxidase, and catalase) on polyethylene, poly(tetrafluoroethylene), and polystyrene treated with plasma immersion ion implantation (PIII) has previously been demonstrated 9–12. These works showed that a significant fraction of the attached protein could not be removed by washing in heated sodium dodecyl sulfate (SDS) solution, which indicated that covalent attachment of the protein molecules to the PIII polymer surface had been achieved without the use of linker molecules or specialized wet chemistry.…”