Ethylenediamine Plasma Research Articles

Development of mass sensitive sensor platform based on plasma polymerization technique: Quartz tuning fork as transducer

This paper describes a modification process of QTFs’ prongs with stable amine containing bilayer plasma polymer film and an application of quartz tuning fork (QTF) as a transducer for biomedical application. To produce stable amine containing film, first, we created plasma polymer films from hexane precursors. We then subjected those films to a second capping layer of ethylenediamine plasma polymer. The film was characterized by contact angle measurement, atomic force microscopy, and X-ray photoelectron spectroscopy. The effect of the interfacial structure onto stability was also analyzed in air. A model protein, BSA, sensing experiments were examined by measuring the shift in the resonance frequency of QTFs. The performance of the proposed sensor was investigated in terms of quality factor. These findings reveal that amine containing bilayer coated QTFs have the potential to be used in mass sensitive biosensor applications for future.

Optimization of Plasma Polymerized Ethylenediamine Film Chemistry on Quartz Particles

Ethylenediamine plasma polymerization has been investigated to modify the surface of quartz particles to optimize the nitrogen concentration of coatings produced via a rotating barrel plasma reactor. Plasma polymerized ethylenediamine (ppED) films were deposited at varying powers, flow rates, and polymerization times. X-ray photoelectron spectroscopy indicated that plasma power appeared to have little effect on ppED chemistry while increasing the ethylenediamine flow rate and polymerization time increased the nitrogen concentration due to reduced fragmentation and increased film thickness respectively. Time of flight secondary-ion mass spectrometry demonstrated uniform distribution of nitrogen species across the particle surface. Ethylenediamine plasma polymerization using a rotating plasma reactor has shown to be a successful method for producing nitrogen rich particle coatings.

Effect of ethylenediamine plasma treatment on fiber post surface

Effect of ethylenediamine plasma treatment on fiber post surface

Comparison between the Effect of Plasma and Chemical Treatments on Fiber Post Surface

Introduction The aim of the present study was to evaluate the fiber post surface after plasma and usual treatments and the adhesion between treated fiber posts and Rely X Unicem resin cement (3M ESPE, St Paul, MN). Methods Flat fiber posts were divided into 6 groups according to surface treatment: silane, hydrofluoric acid, hydrofluoric acid plus silane, plasma polymerization with argon, ethylenediamine plasma (EDA), and the control group. A goniometer was used to measure the contact angle between the groups with water or resin cement. Scanning electron microscopy and electron dispersive spectroscopy were used to examine the topography and chemical changes in the post surfaces after treatment. Push-out tests were performed using a universal testing machine to evaluate the adhesion strength between treated fiber posts and resin cement. Results In the contact angle with water, the most hydrophilic surface was observed in samples treated with argon plasma, followed by treatments with silane and hydrofluoric acid plus silane. The hydrophobic characteristic was observed with EDA and hydrofluoric acid. The contact angle with dual resin cement showed lower values with argon and EDA, followed by silane and hydrofluoric acid plus silane. Electron dispersive spectroscopy analyses showed chemical modifications in the surface after different treatments although topographic changes were verified only with EDA plasma compared with the control. Push-out results did not show differences between groups compared with the control, except for EDA plasma treatment. Conclusions Plasma treatment favored the wettability of the post surface by modifying it chemically. Adhesion improvement was only observed after EDA treatment.

Attachment and Growth of Fibroblasts on Poly(L-lactide/∊-caprolactone) Scaffolds Prepared in Supercritical CO2 and Modified by Polyethylene Imine Grafting with Ethylene Diamine-Plasma in a Glow-Discharge Apparatus

In this study, a copolymer of L-lactide and epsilon-caprolactone (Mn: 73,523, Mw: 127,990 and PI: 1.74) was synthesized by ring-opening polymerization by using stannous octoate as the catalyst. FTIR, 1H-NMR and DSC confirmed the copolymer formation. The copolymer films were prepared and a novel method was developed to produce highly porous sponges for potential use in tissue engineering. Films were subjected to supercritical CO2 at 3300 psi and 70 degrees C to create porous structures for production of possible tissue engineering scaffolds. The pore sizes were in the range of 40-80 microm. The copolymer films were pre-wetted with polyethylene imine (PEI) and then treated with ethylene diamine (EDA)-plasma in glow-discharge apparatus. Gas plasma surface modification of three-dimensional scaffolds fabricated by supercritical carbon dioxide technique was demonstrated to enhance cell adhesion, proliferation, and differentiation over 6 days in culture using L929 fibroblast cell line. Alkaline phosphatase (ALP) activity and glucose uptake in cell culture medium were followed in the cell culture experiments. Fibroblastic cell attachment and growth on the EDA-plasma treated scaffolds were rather low. However, both cell attachment and growth were significantly increased by PEI pre-treatment before EDA-plasma. The changes in ALP activity and glucose uptake also supported the cell growth behavior on these PEI and EDA-plasma treated scaffolds.

Copper Sorption from Aqueous Solutions by Plasma Modified Polyacrylonitrile Beads

The adsorption of Cu(II) ions from aqueous solutions on acrylonitrile(AN) copolymer sorbents has been studied. Porous sorbents from acrylonitrile copolymer-90.6% acrylonitrile (AN), 8.1% methylmethacrylate (MMA) and 1.4% 2-acrylamido-methylpropensylfonic acid (AMPSA) have been prepared and modified by ammonia, air and ethylenediamine plasma. Fourteen types of sorbents have been obtained changing plasma agent and plasma vacuum. The Cu(II) ions uptake has been studied and the sorbent with best sorption characteristics determined. The best sorption uptake has been achieved for the modified sorbent obtained at ethylenediamine plasma modification under 5 Pa plasma vacuum (PAN1-1.20 mgeq/g). Effect of sorbents regeneration after different elution cycles has also been investigated . The sorbents showed high effectiveness of regeneration towards Cu(II) ions, which was above 50% after the IV cycle of elution.

A new approach for immobilization of oligonucleotides onto piezoelectric quartz crystal for preparation of a nucleic acid sensor for following hybridization

The aim of this study is to develop a nucleic acid sensor based on piezoelectric crystal microbalance system (QCM) for following hybridization. Piezoelectric quartz crystal surfaces were first treated in a glow–discharge apparatus with ethylene diamine (EDA) plasma at 15 W (discharge power), 2.5 min (incubation time) and 35 ml/min (monomer flow rate) to create amino groups on the crystal surfaces. The thickness of the EDA–plasma film formed was about 43±24 Å. Then, the amino groups on the crystal surfaces were converted to aldehyde groups by reacting the amino groups with glutaraldehyde (GA) at different conditions. A GA concentration of 2.5% and an incubation time of 2 h were selected as optimal values at this step, corresponding to a GA surface concentration of about 270 ng/cm 2. A double strand Oligonucleotides, having one extra base on 5′-end of one of the complementary strands, were immobilized through the amino groups of this base onto the GA-modified crystals. Optimal immobilization conditions were as follows: oligonucleotide concentration: 1 μg/ml; time: 3 h; pH: 9.2 carbonate buffer; ionic strength: 0.1; and temperature: 20 °C. The QCM sensor carrying the covalently bound strand was used in the hybridization experiments, which showed that equilibrium is achieved in about 5 min, and the frequency shift measured is related to the concentration of the target strand to be measured within the medium.

Investigation of complexation of immobilized metallothionein with Zn(II) and Cd(II) ions using piezoelectric crystals

The aim of this study is to investigate complexation of metallothionein (MT) with cadmium and zinc ions. An oligopeptide (i.e. Lys-Cys-Thr-Cys-Cys-Ala), a fragment of MT was covalently immobilized onto piezoelectric crystals, which were first treated with ethylene diamine plasma in a glow-discharge apparatus, and then were chemically reacted with glutaraldehyde. Complexation of the immobilized MT with Zn(II) and Cd(II) ions in aqueous media was followed by recording the changes of the frequency shifts of the piezoelectric quartz crystals. The amount of Cd(II) ions interacted with the immobilized MT molecules was the highest at pH 7.4, and decreased with an increase in the pH of the medium, in parallel to the decrease in the amount of immobilized MT. The number of Zn(II) ions interacted with the immobilized MT molecules was higher than the number of Cd(II) ions when the adsorption was from solutions containing a single-metal ion with the same ion concentrations. In consecutive adsorption studies, we observed that the type of metal ions used in the first interaction is important. These experiments showed also that there is an exchange between the metal ions, and competition provokes adsorption of both ions due to synergistic–antagonistic effects.