Polycarbonate, immobilization

For on-site measurement from grab sampling, a compact optical device with disposable strips for BOD determination has been developed [36]. The system includes three pairs of light-emitting diodes and photodiodes, and the disposable strips are made of inexpensive, transparent polycarbonate plates, where Pseudomonas fluorescens is immobilized. Using the 2,6-dichlorophenol-indo-phenol sodium salt as chromophore, a linear relationship was observed between the bioluminescence of the exposed strip and the BOD value. 

Liu and Rauch (2003) of Motorola investigated oligonucleotide probe attachment onto polystyrene (PS), polycarbonate (PC), polymethyl methacrylate (PMMA), and polypropylene (PP) plastic surfaces. They utilized three different immobilization processes SurModics surface modification solution (that allows attachment of adsorbed reactive groups to a surface by photoactivation of polymers at 254 nm). Pierce Reactive-Bind coating solution, and CTAB (cetyltrimethylammonium bromide, a cationic detergent). Not surprisingly, the microarray performances on these plastics varied. 

In the same way, o-nitrophenyl octyl ether (o-NPOE) was immobilized on polycarbonate (PC) filters and the apparent permeability measured after 5 h incubation time was correlated to log Pnpoe for a series of reference compounds (log Pnpoe ranging from —1 to 3.6) [90]. Lipophilicity values in the alkane/water system were also determined using PAMPA with hexadecane-PC coated filters [89]. In this case, a correlation was found between intrinsic permeability (log Pq, permeability corrected for ionization and for unstirred water layer contribution, which particularly affects permeability of lipophilic compounds) and log P ik. However, log Pq is obtained from the knowledge of the pJC, value(s) and the permeability pH profile and therefore requires the full permeability pH profile to be measured for each compound, which negatively impacts the assay throughput. 

Immunomagnetic cell separation can be used to further debulk re mixture of white blood cells obtained from the density gradient eparation and thus further enrich the suspension with rare cancer ells (see Chapter 21). Before immunochemical staining, it is usual 5 concentrate the cells onto polycarbonate membranes so that they re immobilized (see Note 8). 

Alternative Polymers for Immobilizing Bizymes. Vinyl acetate (after hydrolysis with bicarbonate) and polycarbonate have also been chemically modified to accommodate glucose oxidase (Donlan,A.M. Mcxx3y,G.J. Thomas,J.D.R., Uiiversity of Wales (Allege of Cardiff, unpublished data). 

Acetylcholineesterase Biosensors were fabricated from filter-supported solventless bilayer lipid membrane (BLM) and used for the analysis of the substrates of hydrolytic enzymes in a flowthrough system. The codeposition of lipid (dipalmitoyl-phosphatidic acid) and protein solutions to form a BLM on a microporous glass fiber or polycarbonate ultra-filtration membrane disc was described. Enzyme was immobilized on the membrane by incorporation of protein solution into the lipid matrix at the air-electrolyte interface before BLM formation. 

The novel water-soluble dye 64 shows sufficient stability for potential application in molecular-based beacons for cancer detection using optical imaging <2005BCC735>. An optochemical ozone sensor with a quantitation limit of 0.03 ppm and accuracy exceeding 8% has been obtained by immobilization of the novel soluble indigo derivative 65 in permeable transparent polymeric films of polydimethylsiloxane-polycarbonate <2005MI1628>. 

Magno et al. [65] reported an amperometric biosensor for fructose using an electrode prepared by dispersion of MWCNT within mineral oil (60/40 % w/w) and covered by a polymer obtained from the electropolimerization of dihydroxybenzaldehyde. The fructose dehydrogenase was immobilized on different membranes placed on the top of CNTPEs and then covered with an additional polycarbonate membrane (0.03 pm pore size) to prevent fouling and microbial attack. 

A completely independent and parallel study made by Assink using pulsed NMR for ammonia sorbed in polystyrene also aiggests that partial immobilization occurs in thb gla y prfyiiKr/penetrant system. The mobility of the Langmuirian population in this case was less than 5% as large as the mobility of the Henry s law mode. The data of Paul and Koros indkated mobilities of penetrant in the Langmuir trade relative to the Henry s law nrade ranging from 8% for CO 2 up to 100% for He in polycarbonate and from 6% to 10% for CO2 in PET between 35 °C and 75 °C. 

Fig. 19.10 Inspection of the pH reagent immobilized in a cellulose acetate film and deposited onto a polycarbonate copolymer material upon immersion in solutions of low (a) and high (b) pH...

Mullen et al. (1986) decreased the permeability of LOD membranes in order to extend the linear range to higher lactate concentration. A polycarbonate membrane was treated with methyltrichlorosilane prior to enzyme immobilization by crosslinking with glutaraldehyde and BSA. In this way the upper limit of linearity was shifted from 0.2 to 18 mmolA. The permeation of electrochemical interferents was diminished concomitantly. On the other hand, the silanization increased the response time from 0.5-1 min to 1-3 min and reduced the sensitivity by 98-99%. 

Other lactate analyzers use lactate oxidase (LOD). Clark et al. (1984b) use the enzyme in the YSI23L instrument (USA) as immobilized between a cellulose acetate membrane and a polycarbonate membrane, the latter serving to exclude high-molecular weight interferents. Lactate measurement in whole blood pipetted immediately after withdrawal into the phosphate buffer stream of the analyzer yielded the following correlation with values obtained with deproteinized blood (Weil et al., 1986) ... 

Gas Permeable Membrane Aerator Bioreactor. This type of bioreactor has not yet been fully developed. Nevertheless, some information is available. For example, one bioreactor is equipped with an aerator composed of fine tubes made of polycarbonate, polypropylene, silicone gum, etc. This type of bioreactor should be valuable for immobilized plant cell cultures. 

Immobilized CALB has frequently been applied in the literature as a catalyst for polymerization of aliphatic polyesters, polycarbonates, polyurethanes and their copolymers. In the present work on CALB catalyzed polymerization, the ring opening of e-caprolactone to polycaprolactone was selected as the model polymerization reaction (Figure 3.3). This model reaction has been well established in the literature [24-27] as an example of a polymerization reaction that can be successfully catalyzed by immobilized lipases (see also Chapter 4). Polymer synthesis and characterization was performed in four steps (i) polymerization (ii) separation (iii) purification and (iv) characterization. 

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