Immobilization Parameters Research Articles

An immobilized invertase enzyme for the selective determination of sucrose in fruit juices

Poly(N-vinylpyrrolidone-co-butylacrylate-co-N-hydroxymethylacrylamide) has been synthesized by free radical polymerization at 70 °C. Copolymer were characterized by FT-IR, elemental analysis and viscometric methods. Invertase was immobilized onto poly(N-vinyl pyrrolidone-co-butyl acrylate-co-N-hydroxymethyl acrylamide) by entrapment method. Optimum parameters (pH, temperature, substrate concentration, amount of polymer) for immobilization to obtain maximum activity were investigated. Kinetic parameters, Km and Vmax, of the free and immobilized invertases were also assayed. Results showed that immobilization enhanced the enzyme stability against changes of pH and temperature and immobilized enzyme showed lower Km value than free enzyme. One of the most interesting results is that the optimum operational temperature of the immobilized enzyme was 15 °C higher than that of the free enzyme. The next is the activity of the immobilized enzyme at the optimum temperature (70 °C) was approximately the same as the activity of the free enzyme at its optimum temperature (55 °C). Finally, immobilized invertase were used for determination of sucrose in commercial fruit juices. A new method and equation based on immobilized invertase were derived for determination of sucrose in commercial cheryy and pomegranate juices.

Immobilization of Pectinase onto Porous Hydroxyapatite/Calcium Alginate Composite Beads for Improved Performance of Recycle.

Pectinase is an industrially important enzyme widely used in juice production, food processing, and other fields. The use of immobilized enzyme systems that allow several reuses of pectinase is beneficial to these fields. Herein, we developed mechanically strong and recyclable porous hydroxyapatite/calcium alginate composite beads for pectinase immobilization. Under the optimal immobilization parameters of 40 °C, pH 4.0, 5.2 U/L pectinase concentration and 4 h reaction time, pectinase showed the highest enzymatic activity (8995 U/mg) and immobilization yield (91%). The thermal stability and pH tolerance of the immobilized pectinase were superior to those of free pectinase. The storage stability of the free and immobilized pectinase for 30 days retained 20 and 50% of their initial activity, respectively. Therefore, these composite beads might be promising support for the efficient immobilization of industrially important enzymes.

Optimizing Immobilization and Stabilization of Feruloyl Esterase from Humicola Insolens and its Application for the Feruloylation of Oligosaccharides

Feruloyl esterase (FAE)-catalyzed esterification reaction is as a potential route for the biosynthesis of feruloylated oligosaccharides as functional ingredients. Immobilization of FAE from Humicola insolens on metal chelate-epoxy supports was investigated. The study of effects of immobilization parameters using response surface methodology revealed the significance of enzyme/support ratio (3.25-29.25 mg/g support), immobilization time (14-38 h), buffer molarity (0.27-1.25 M) and pH (4.0-8.0). The interactions between enzyme-to-support ratio/buffer molarity and enzyme-to-support ratio/pH were found to be critical for the modulation of the immobilization activity yield and the retention of specific activity, respectively. Optimum conditions for FAE-immobilization on metal chelate Sepabeads® EC-EP R were identified to be 22.75 mg FAE/g support, pH of 5.0, 27.7 h and buffer molarity of 0.86 M. At these conditions, an activity yield of 82.4%, a specific activity retention of 143.4%, and an enzyme activity of 395.4 μmol/min. g support were achieved. Further incubation of the immobilized FAE at pH 10.0 improved its thermostability. Increasing the pore size of the epoxy support improved the retention of FAE hydrolytic activity and the esterifying efficiency of the immobilized biocatalyst. Optimally immobilized and stabilized FAE on metal chelate-epoxy support retained up to 92.9% of the free enzyme feruloylation efficiency to xylooligosaccharides..

Tailoring a stable and recyclable nanobiocatalyst by immobilization of surfactant treated Burkholderia cepacia lipase on polyaniline nanofibers for biocatalytic application

Polyaniline nanofibers were synthesized by the oxidative polymerization of aniline. Surfactant treated lipase from Burkholdaria cepacia was immobilized on these polyaniline nanofibers by adsorption. The activity of immobilized preparation was six times higher than that of free lipase with an enhanced dispersion in organic solvents. Five-level-four-factor central composite design was applied for the optimization of immobilization parameters (viz. reaction time, pH, stirring rate and enzyme-support ratio) which were evaluated on the basis of lipase loading and activity. The thermal stability of the lipase in the nanobioconjugate, demonstrated in terms of the half-life at 80 °C was almost sixteen-fold higher than in the free form. The reusability data revealed the utility of the nanoconjugate for seven consecutive cycles with a slow and gradual decline in the activity. However, the nanoconjugate retained almost 30% of their initial activity after seven cycles of reuse revealing its utility of in industrial applications. The nanoconjugate was used in the kinetic resolution of (RS)-1-(7-(3-chloro-2-hydroxypropoxy)benzofuran-2-yl) ethanone, racemic intermediate of an important β-blocker (Befunolol), with a high conversion rate of 48.2%, 98% ee-value and enantioselectivity (E) of 188, which signify its importance as a nanobiocatalyst.

Development of an eco-friendly antibacterial textile: lysozyme immobilization on wool fabric.

Lysozyme, a type of natural enzyme, has been widely used for bacteriostatic functionalization of various materials due to its efficient and selective antibacterial properties. Herein, we report the preparation and characterization of an eco-friendly antibacterial textile based on the immobilization of lysozyme from chicken egg white onto wool fibers. Tris(hydroxymethyl)phosphine (THP) was employed as the cross-linker for the immobilization of lysozyme on the surface of wool fiber. The mechanism of THP cross-linking was investigated via phosphorus test, energy-dispersive spectroscopy (EDX) and Fourier transform infrared spectroscopy (FT-IR). The surface staining, optimization of immobilization parameters, morphology, antibacterial properties, and durability of wool fibers with immobilized lysozyme were also assessed. The results show that hydroxymethyl groups of THP reacted with amino groups of wool fiber and lysozyme through Mannich reaction, which successfully immobilized lysozyme on the wool fiber. The wool fibers incorporated with lysozyme had better antibacterial properties and durability compared with the untreated wool fabric. This facile immobilization approach of lysozyme provides an effective strategy for environmentally benign modification and functionalization of keratin and keratin-containing materials.

Comparison of batch and repeated batch operation of lactulose synthesis with cross-linked aggregates of Bacillus circulans β-galactosidase

Synthesis of lactulose with crosslinked aggregates of Bacillus circulans β-galactosidase (CLAGs) has been compared in batch and repeated-batch operation for the first time. The effect of the type of the precipitating agent and its concentration, the crosslinker concentration and the time of crosslinking were evaluated for their effect on the parameters: immobilization yield, specific activity and thermal stability of the biocatalysts. The type and concentration of the precipitating agent were the variables that produced a significant variation in the immobilization parameters of the biocatalyst. CLAGs were obtained with a specific activity of 7790 IUH⋅g−1 at an immobilization yield of 46.2 % using 50 % v/v of propanol as precipitating agent, 5.5 gglutarldehyde gprotein−1 for crosslinking and 1 h of crosslinking time. This biocatalyst was more stable than the free enzyme with a stabilization factor of 11.3 h at 50 °C. Highest yield of lactulose synthesis with CLAGs was 0.42 g g−1 for a fructose/lactose molar ratio of 8. Repeated-batch operation allowed a significant increase in lactulose production per unit mass of biocatalyst and in cumulative productivity with respect to batch operation, yielding an efficiency of biocatalyst use of 2.43 kglactulose gbiocatalyst protein−1.

A Multidisciplinary Approach to Implement Image-Guided Craniospinal Irradiation

ButLes considérations pratiques dictent un changement dans la technique craniospinale (CSI). Nous faisons rapport de notre expérience dans l’élaboration et l'affinage des paramètres de planification et de traitement CSI, en utilisant la technique de radiothérapie à modulation d'intensité guidée par l'image (IG-IMRT). Méthodologie et matérielDeux valeurs institutionnelles ont guidé le développement: la prise de décision multidisciplinaire et la coordination des considérations tout au long de la simulation, de la planification et de la prestation des soins. La paramètres d'immobilisation du patient et de simulation ont été choisis en fonction des limitations des systèmes de prestation des traitements. Des cartes de mesure de fluence ont été acquises afin de vérifier la dose dans les zones de chevauchement. Une analyse de robustesse a été faite afin d’évaluer les répercussions des erreurs potentielles de positionnement mesurées par la vérification IGRT. Les considérations liées au traitement comprennent l'ordre d'imagerie des isocentres et l'ordre de traitement, ainsi que les valeurs respectives de fréquence IGRT, de modalité et de seuils de superposition d'images. RésultatsLes mesures globales sur film se situaient à moins de 3% des doses planifiées, confirmées par des mesures sur fantôme composite montrant que tous les points se situaient à au moins 97% de la dose planifiée. L'analyse de sensibilité du positionnement suggère qu'une tolérance de positionnement de 3 mm était suffisante pour assurer la confiance envers le plan administré. Comme les organes à risque les plus importants se situaient dans l'isocentre supérieur, l'ordre de traitement quotidien des isocentre a été confirmé ainsi: supérieur, milieu, inférieur. Le guidage quotidien par tomodensitométrie à faisceau conique a été retenu pour tous les isocentres (seuil de rotation de 3°). Sauf dans la direction supéro-inférieure des isocentres du milieu et inférieur, ajustée à 3 mm conformément aux résultats de l'analyse de sensibilité, un seuil translationnel de 1 mm a été utilisé. ConclusionsUne technique CSI pour la radiothérapie à modulation d'intensité guidée par l'image a été développée et mise en œuvre dans notre institution en utilisant une approche multidisciplinaire. Ce processus met en lumière l'approche collaborative et itérative utilisée pour intégrer avec succès une nouvelle technique de traitement dans une ère de guidage par l'image.

Immobilization of \u03b2-Galactosidase From Aspergillus oryzae on Electrospun Gelatin Nanofiber Mats for the Production of Galactooligosaccharides

Two simple and easily reproducible methods for the immobilization of β-galactosidase (β-gal) from Aspergillus oryzae on electrospun gelatin nanofiber mats (GFM) were developed. The process was optimized regarding the electrospinning solvent system and the subsequent cross-linking of GFM in order to increase their stability in water. β-Gal was covalently immobilized on activated gelatin nanofiber mats with hexamethylenediamine (HMDA) as a bifunctional linker and secondly via entrapment into the gelatin nanofibers during the electrospinning process (suspension electrospinning). Optimal immobilization parameters for covalent immobilization were determined to be at pH 7.5, 40 °C, β-gal concentration of 1 mg/mL and immobilization time of 24.5 h. For suspension electrospinning, the optimal immobilization parameters were identified at pH 4.5 and β-gal concentration of 0.027 wt.% in the electrospinning solution. The pH and temperature optima of immobilized β-gal shifted from 30 °C, pH 4.5 (free enzyme) to pH 3.5, 50 °C (covalent immobilization) and pH 3.5, 40 °C (suspension electrospinning). Striking differences in the Michaelis constant (KM) of immobilized β-gal compared with free enzyme were observed with a reduction of KM up to 50% for immobilized enzyme. The maximum velocity (vmax) of immobilization by suspension electrospinning was almost 20 times higher than that of covalent immobilization. The maximum GOS yield for free β-gal was found to be 27.7% and 31% for immobilized β-gal.

Immobilization of fluorescent bacterial bioreporter for arsenic detection.

Whole-cell bacterial biosensors hold great promise as a practical complementary approach for in-field detection of arsenic. Although there are various bacterial bioreporter systems for arsenic detection, fewer studies reported the immobilization of arsenic bioreporters. This study aimed at determining immobilization of specific bacterial bioreporter in agar and alginate biopolymers to measure level of arsenite and/or arsenate. To achieve sensitive detection, immobilization parameters of polymer concentration and cell density were evaluated. Moreover, by changing the culture medium, immobilized bioreporter cells in minimal medium can detect arsenite while they can detect both arsenite and arsenate in phosphate-limited minimal medium. When optimal parameters were applied, agar and alginate immobilized bioreporter systems can detect arsenite and arsenate concentrations of 10μg/l and 200μg/l within 5h and 2h, respectively. The results showed that the immobilized bacterial bioreporter systems are able to determine the concentrations of the two abundant species of arsenic; arsenite and arsenate, as opposed to other studies which reported only arsenite detection. This is the first study describe agar hydrogel and alginate bead immobilization of fluorescent arsenic bacterial bioreporter that can detect both arsenite and arsenate at the safe drinking water limit. Thus, this study will enable further steps to be taken towards developing sensitive and selective portable devices to assess environmental arsenic contamination and prevent acute arsenic toxicity.

Amperometric Glucose Biosensor Based on Homopolymer-Chitosan Double Layered Glucose Oxidase Electrode Modified with Zinc Oxide Nanoparticles

GOD was immobilized onto polypyrrole (PPy) or poly(o-anisidine) (POA) coated Pt electrode to construct glucose sensitive biosensor. Because polymer film properties and enzyme activity affect the current response, PPy and POA synthesis conditions and also enzyme immobilization parameters were optimized in detail. The optimal monomer concentrations were determined as 25 and 50 mM for PPy and POA, respectively, whereas scan rate was 50 mV/s for both polymer films. In case of immobilization procedure, the optimal Chitosan (Chi), glucose oxidase (GOD) and glutaraldehyde (GAL) concentrations were determined as 0.5%, 2 mg/ml and 0.05% for PPy and 0.5%, 4 mg/ml and 0.075% for POA, respectively. Zinc oxide nanoparticles (ZnONP) were co-immobilized with GOD enzyme and it was revealed that ZnONP modification enhanced the efficiencies of both electrodes in terms of current responses and stabilities. Nyquist diagrams showed that enzyme electrodes were sensitive to glucose molecule and ZnONP modification improved the sensor efficiency.

EFFECT OF IMMOBILIZATION PARAMETERS ON THE IMMOBILIZATION OF CYCLODEXTRIN GLUCANOTRANFERASE ON HOLLOW FIBER MEMBRANE

Cyclodextrin (CD) is a non-reducing maltooligosaccharides which able to form inclusion complexes with many hydrophobic molecules, changing their physical and chemical properties. With these properties, CD has been discovered to have numerous applications in food industries, pharmaceutical, agricultural and environmental engineering. CD is produced by the enzymatic reaction between cyclodextrin glucanotransferase (CGTase) and starch. Various enzyme immobilization techniques such as adsorption, entrapment, encapsulation and cross-linking have been applied to improve the production of CD. Some of the immobilization parameters such as contact time, agitation rate and pH of the immobilization solution play a vital role in enzyme immobilization process, in order to achieve high production of CD. In the present study, the CGTase from Bacillus licheniformis was immobilized on polyvinylidene difluoride (PVDF) hollow fiber membrane via adsorption technique. The efficiency of enzyme immobilization appears to be affected by various factors (immobilization parameters) such as contact time, agitation rate and pH. Therefore, the effect of contact time (6-72 h), agitation rate (50-250 rpm) and pH (3-10) on the immobilization of CGTase on PVDF hollow fiber membrane were investigated in this study. The immobilized CGTase exhibited the highest immobilization yield of 69.37% under the conditions of 24 h contact time, 100 rpm and pH 7.0. Therefore, the influence of the immobilization parameters during the enzyme immobilization process is vital in order to achieve the high production of CD. Hence, high immobilization yield contributed to the high production of CD which in turn may be beneficial for the industrial purposes.

Immobilization of enzymes on iron oxide magnetic nanoparticles: Synthesis, characterization, kinetics and thermodynamics.

Immobilization of enzymes on matrices like iron oxide magnetic nanoparticles provides a new technique against the stagnant conventional approaches for stabilization of enzymes. Along with ease in synthesis and modification, the advantages of using these iron oxide nano-metallic matrices as enzyme support matrices are three dimensional viz. structural and thermal stability, storage stability, and reusability. This book chapter details the protocol(s) for synthesis of iron oxide magnetic nanoparticles via chemical co-precipitation method, its surface modification and functionalization with 3-aminopropyl-triethoxysilane (APTES), followed by immobilization of enzymes using glutaraldehyde as a cross linker. A detailed protocol for instrumental characterization is also described. Additionally, the chapter also elucidates the basic characterization of enzyme(s), effect of operating conditions (pH, temperature) on the enzyme activity, thermal inactivation kinetics, thermodynamic parameters, storage stability, and reusability of the free and immobilized enzymes. Further, the results of all the indicated protocols and stability studies are thoroughly discussed with the findings on immobilization of cellulase in a tri-enzyme mixture on iron oxide magnetic nanoparticles. The optimum parameters for immobilization were 30mM glutaraldehyde with 3h incubation and 3:1 (w/w) ratio of nanoparticles:protein content. Immobilization altered the kinetic constants (Km and Vmax) marginally but enhanced the thermal stability as evident from inactivation kinetic constants (kd, t1/2 and D-value) and thermodynamic parameters (Ed, ΔH°, ΔG° and ΔS°) within 55-75°C. The immobilized cellulase retained 71.68±3.48% activity during 21-day storage, and 81.15±5.27% activity till fifth reusability cycle.

Correction to: Phytase Immobilization on Hydroxyapatite Nanoparticles Improves Its Properties for Use in Animal Feed.

Inthe original version of this article, under Calculation of Immobilization Parameters heading, the presentation of the equations are incorrect. The correct presentation of the equations are given below.

Immobilization of Lipase A from Candida antarctica onto Chitosan-Coated Magnetic Nanoparticles.

In this communication, lipase A from Candida antarctica (CALA) was immobilized by covalent bonding on magnetic nanoparticles coated with chitosan and activated with glutaraldehyde, labelled CALA-MNP, (immobilization parameters: 84.1% ± 1.0 for immobilization yield and 208.0 ± 3.0 U/g ± 1.1 for derivative activity). CALA-MNP biocatalyst was characterized by X-ray Powder Diffraction (XRPD), Fourier Transform Infrared (FTIR) spectroscopy, Thermogravimetry (TG) and Scanning Electron Microscope (SEM), proving the incorporation of magnetite and the immobilization of CALA in the chitosan matrix. Besides, the immobilized biocatalyst showed a half-life 8–11 times higher than that of the soluble enzyme at pH 5–9. CALA showed the highest activity at pH 7, while CALA-MNP presented the highest activity at pH 10. The immobilized enzyme was more active than the free enzyme at all studied pH values, except pH 7.

Effect of Glutaraldehyde Concentration on Catalytic Efficacy of <i>Candida rugosa</i> Lipase Immobilized onto Silica from Oil Palm Leaves

Till date, studies that investigated the effect of glutaraldehyde concentration on catalytic efficacy of biocatalyst developed with silica-derived from oil palm leaves (OPL) as support, are unknown. The study presents the preparation of a support consisting of silica extracted from OPL coated over magnetite (G/A/SiO2-M) for the immobilization of Candida rugosa lipase (CRL). Herein, the effect of glutaraldehyde concentration on the catalytic efficacy of immobilized CRL was assessed by the enzymatic production of butyl butyrate as a model. Fourier transform infrared (FTIR) spectra and immobilization parameters indicated that covalent bound CRL on functionalized OPL-derived silica-magnetite composite activated with 4% (v/v) glutaraldehyde solution (100 mM, pH 7.0) (CRL/G/A/SiO2-M) and pretreated in toluene, resulted in a protein loading and an immobilization yield of 68.3 mg/g and 74.3%, respectively. The resultant CRL/G/A/SiO2-M biocatalyst which specific activity was 61.9 U/g catalyzed the esterification production of 76.5% butyl butyrate in just 3 h, as confirmed by analyses of the purified ester using FTIR and 1H NMR spectroscopy. Hence, the finding envisages the promising use of G/A/SiO2-M support fabricated from discarded OPL as a carrier for immobilization and activation of CRL, in conjunction to being a good alternative source of renewable silica.

Various methods to combine hyaluronic acid and antimicrobial peptides coatings and evaluation of their antibacterial behaviour

To prevent bacterial adhesion and contamination, biomaterials exhibiting both antiadhesive and biocidal properties are the most promising way. However, control of the properties combination is not so easy due, in particular, to antagonist mechanisms. Antibacterial surfaces against Staphylococcus epidermidis adhesion were here elaborated by using both nisin grafting and repelling polysaccharide coating. We evaluated two strategies aiming to improve the antimicrobial peptide (AMP) immobilization parameters (i.e., the accessibility and/or local density) in order to obtain the best antimicrobial activity on surfaces. We thus (i) grafted the nisin on a surface previously coated with hydrolyzed hyaluronic acid (HA) (to decrease the length of the polysaccharide chains) or (ii) coupled nisin and HA in solution before grafting this complex on surfaces. XPS analysis pointed out a lower amount of nisin on the surface for both approaches compared to the immobilization of nisin on native HA. However, an antibacterial activity was maintained, probably due to a higher local density of the AMP when surfaces were modified with hydrolyzed hyaluronic acid, leading to a better combination of antiadhesive-biocidal properties. Microscopy fluorescent observations demonstrated that accumulation of dead cells was also avoided by some coatings architecture.

Immobilization of cyclodextrin glucanotransferase on hollow fiber membrane: optimization of the immobilization parameters by response surface methodology

Cyclodextrin glucanotransferase (CGTase) is a multifunctional industrial enzyme which undergoes cyclization reaction to converts starch into cyclodextrin. Due to their potential properties, cyclodextrin has been discovered to have numerous application in food industries, pharmaceuticals, agriculture and environmental engineering. However, the instability of the enzyme during the reaction process result in the low production of cyclodextrin. Thus, enzyme immobilization process has been used to improve the enzyme stability in order to achieve high production of cyclodextrin. In this study, CGTase from Bacillus licheniformis was immobilized on polyvinylidene difluoride hollow fiber membrane via physical adsorption. The optimization of the immobilization parameters and the performance of the immobilized CGTase were investigated. The adsorption of CGTase on hollow fiber membrane was evaluated by fourier transform infrared spectroscopy. Response surface methodology was employed to optimize enzyme immobilization by manipulating the immobilization parameters of contact time (15-33 h), immobilization pH (pH 6-8) and immobilization temperature (20-30 °C) on the immobilization yield. The optimized immobilization conditions were 24 °C of immobilization temperature, pH 6.7 and 24 h of contact time, with 88.25% of immobilization yield. Immobilization of CGTase on the hollow fiber membrane was successfully optimized and about 4.6-fold increment of immobilization yield was achieved after the optimization process. The kinetic parameters of the immobilized CGTase were 9.42 mgml−1 h−1 and 9.99 mg ml−1 for Vmax and Km value, respectively. The kinetic studies revealed that the catalytic efficiency of the immobilized CGTase was similar to the free CGTase, demonstrated that upon the immobilization process, adsorption of CGTase on hollow fiber membrane does not cause structural changes to the enzyme. Hence, immobilization of CGTase on the hollow fiber membrane substantially improved the production of cyclodextrin and suggesting that the hollow fiber membrane appeared as a suitable support for the enzyme immobilization system.

Immobilization of Alcohol Dehydrogenase on Titania Nanoparticles To Enhance Enzyme Stability and Remove Substrate Inhibition in the Reaction of Formaldehyde to Methanol

Both physical and chemical procedures were applied to immobilize yeast alcohol dehydrogenase (yADH) on titania nanoparticles. It was found that chemical immobilization is an authentic method due to providing a strong bond between the enzyme and the support. The immobilization was confirmed by Fourier transform infrared spectroscopy and transmission electron microscopy. The immobilization parameters such as enzyme concentration, time of immobilization, and glutaraldehyde concentration were optimized based on the maximum immobilization yield and the best enzyme catalytic performance. Activity and kinetics of yADH before and after immobilization were studied, and the stability of enzyme at different pHs and temperatures was investigated. The optimum pH for the incubation and activity of yADH was obtained at 7.0, and the activity of immobilized yADH reached more than 80% of its initial activity after 30 days of storage at 4 °C. The reusability of yADH was improved by immobilization as revealed by retaining 84...

Label-free electrochemical immunosensor for quick detection of anti-hantavirus antibody

This report describes the preparation and evaluation of an immunosensor based on chemical modification of gold surface with hantavirus (strain Araucaria) antigen/protein and the antibody detection by electrochemical analysis. The viral nucleoprotein was immobilized onto gold by SAM formation with 3-mercaptopropionic acid (MPA) followed by activation of the surface using N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride and N-Hydroxysuccinimide (EDC/NHS). Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and quartz crystal microbalance (QCM) measurements were used for evaluation of each step involved in the construction of the proposed immunosensor. Several experimental conditions were studied and after optimization of immobilization parameters, the device showed good stability within 21days and selectivity for a qualitative detection of specific antibody (IgG) directed against hantavirus Araucaria. The proposed sensor had shown a linear response for concentration varying between 0.400 and 300μgmL−1 allowing its application in spiked serum samples for detection of specific antibody of hantavirus Araucaria based on a cutoff value. The immunosensor showed a sensitive response to the spiked samples and can be employed as an alternative for the qualitative diagnosis of hantavirus infections.

Parameter dependency of DNA origami immobilization at micro- and nano structured CF polymer surfaces on SiO2

Folded single-stranded DNA of various shapes – so called DNA origami [1,2] – have become a growing interest for nanotechnology in the recent years. The main reason is the possibility to connect top-down with bottom-up technology by the construction of nanometer sized bio-templates. On this way, a variety of different structures (2D as well as 3D) could be realized and on those top functionalities or objects of interest could be arranged with a spatial resolution of about2-3nm for devices like plasmonic antennas or optical waveguides [3].This contribution presents the latest results of a successful immobilization of DNA origami templates on the assembly of structures in the micrometer range in a cavity contrast of thin CF polymer layers on SiO2. The dependency of immobilization behavior for two different DNA origami geometries was investigated for different immobilization parameters (activation time, concentration of DNA origami and incubation time of DNA origami solution)