Coimmobilization

Figure 13 shows pH response of bromothymol blue (BTB) as coimmobilized non fluorescent pH indicator detect by fluorescence. 

As mentioned above, in order to extend the potentialities of the luminescence-based optical fibre biosensors to other analytes, auxiliary enzymes can be used. The classical approaches consist either of the coimmobilization of all the necessary enzymes on the same membrane or of the use of microreactors including immobilized auxiliary enzymes and... 

A strain of yeast and a strain of bacterium were co-immobilized to fabricate a biochemical oxygen demand (BOD) sensor based on sol-gel derived composite materials97. This novel type of biosensor was developed for water monitoring and was used to determine the BOD values of OECD synthetic wastewater, domestic wastewater, and lake waters. The microorganisms Trichosporon cutaneum and Bacillus subtilis were coimmobilized in the sol-gel composite material, which was composed of silica and the grafting copolymer of poly (vinyl alcohol) and 4-vinylpyridine (PVA-g-P(4-VP)). 

In view of the conductive and electrocatalytic features of carbon nanotubes (CNTs), AChE and choline oxidases (COx) have been covalently coimmobilized on multiwall carbon nanotubes (MWNTs) for the preparation of an organophosphorus pesticide (OP) biosensor [40, 41], Another OP biosensor has also been constructed by adsorption of AChE on MWNTs modified thick film [8], More recently AChE has been covalently linked with MWNTs doped glutaraldehyde cross-linked chitosan composite film [11], in which biopolymer chitosan provides biocompatible nature to the enzyme and MWNTs improve the conductive nature of chitosan. Even though these enzyme immobilization techniques have been reported in the last three decades, no method can be commonly used for all the enzymes by retaining their complete activity. 

R. Fernandez-Lafuente, V. Rodriguez, and J.M. Guisan, The coimmobilization of D-amino acid oxidase and catalase enables the quantitative transformation of D-amino acids (D-phenylalanine) into alpha-keto acids (phenylpyruvic acid). Enz. Microb. Technol. 23, 28-33 (1998). 

C.H. Lei and J.Q. Deng, Hydrogen peroxide sensor based on coimmobilized methylene green and horseradish peroxidase in the same montonorillonite-modified bovine serum albumin-glutaraldehyde matrix on a glassy carbon electrode surface. Anal. Chem. 68, 3344—3349 (1996). 

B.H. Liu, F. Yan, J.L. Kong, and J.Q. Deng, A reagentless amperometric biosensor based on the coimmobilization of horseradish peroxidase and methylene green in a modified zeolite matrix. Anal. Chim. Acta 386, 31-39 (1999). 

Su Y, Zhang Y, Wang J et al (2009) Enhanced bio-decolorization of azo dyes by coimmobilized quinone-reducing consortium and anthraquinone. Bioresour Technol. doi 10.1016/j.biortech.2009.01.029... 

Choline-containing phospholipids have been determined in human serum using an IMER consisting of coimmobilized phospholipase D and choline oxidase [51]. Recently, immobilized glutamate oxidase was used to determine L-glutamic acid in culture media [52],... 

A flow assay was reported for determination of inorganic pyrophosphate a pyrophosphatase was coimmobilized with luciferase on Sepharose beads with continuous flow of saturating concentrations of substrates. The instrument allowed automation with a throughput of approximately one sample every 4 min. 

Glutamate, glutamine Coimmobilized glutamate oxidase + glutaminase, Luminol-H202 CL 0.1 (J.M glutamate, 1 (J.M glutamine 44... 

Similar to the work described by Spohn et al. [34], a trienzyme sensor was developed recently for the determination of branched-chain amino acids (L-valine, L-leucine, and L-isoleucine). Leucine dehydrogenase, NADH oxidase, and peroxidase were coimmobilized covalently on tresylate-hydrophylic vinyl polymer beads and packed into a transparent PILL tube (20 cm X 1.0 id), which was used as flow cell. The sensor was free of interferences from protein and NH4+ and it was stable for 2 weeks. The sensor system was applied to the determination of branched-chain amino acids in plasma with recoveries ranging from 98 to 100% [36],... 

The copper flow-through CL sensor comprised an anion-exchange column having luminol and cyanide coimmobilized on the resin, while copper was temporarily retained by electrochemical preconcentration on a Au electrode placed in an anodic stripping voltammetric cell [64], Injection of 0.1 mol/L NaOH through the column eluted the reagents, which then reacted with copper, stripped from the electrode to produce a CL signal. The response was linear in the 0.01-10-pg/L... 

Fig. 7. Horse-liver alcohol dehydrogenase (HLADH) catalyzed alcohol oxidation at a graphite felt anode modified by poly(acrylic acid) (PAA) under coimmobilization of ferrocene derivatives (Fc), diaphorase (Dp), and HLADH [39]...

Coimmobilization of the viologen and the VAPOR enzyme at the surface of a carbon cathode can be used for the electrochemical production of NADH from NAD+ at a rate of 9 nmolh-1 cm-2 [55,61,62]. 

Martins dos Santos, V. A. R, Vasilevska, T., Kajuk, B., Trampeg J., Wijffels, R. H. (1997) Production and characterization of double-layer beads for coimmobilization of microbial cells. Biotechnology Annu. Rev., 3, 227-44. 

C. Burstein, H. Ounissi, M. D. Legoy, G. Gellf, and D. Thomas, Recycling of NAD using coimmobilized alcohol dehydrogenase and E. coll, Appl. Biochem. 

When [W(CN)s] " was coimmobilized with BOD and poly(L-lysine) on carbon felt sheet of 1-mm thickness on an RDE, a current density of 17 mA/ cm was observed at 0.4 V and 4000 rpm in oxygen-saturated phosphate buffer, pH 7. The authors partially attribute the high current density to convective penetration of the oxygen-saturated solution within the porous carbon paper electrode. This assertion is justified by calculation of an effective electrode area based on the Levich equation that exceeds the projected area of the experimental electrode by 70%. ° This conclusion likely applies to any... 

Stein EW, Volodkin DV, McShane Ml, Sukhomkov GB. Real-time assessment of spatial and temporal coupled catalysis within polyelectrolyte microcapsules containing coimmobilized glucose oxidase and peroxidase. Biomacromolecules 2006 7 710-719. 

Chakrabarti, A.C. and Storey, K., Enhanced glucose production from cellulose using coimmobilized cellulase and beta-glucosidase, Appl. Biochem. Biotechnol., (1989) 22, 3, 263-78. 

Lin, J-E., Wang, H. Y. Hickey, R. F. (1991). Use of coimmobilized biological systems to degrade toxic organic compounds. Biotechnology and Bioengineering, 38, 273-9. 

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