Choline determination based on the intrinsic and the extrinsic (chemically modified) fluorescence of choline oxidase

Galbán, Javier; Sánchez-Monreal, Olga; Andreu, Yolanda; Marcos, Susana de; Castillo, Juan R.

doi:10.1016/j.ab.2004.04.015

Cited by 16 publications

(14 citation statements)

References 18 publications

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“…However, via an enzymatic reaction with choline oxidase (ChOx), choline is oxidized to betaine with the simultaneous production of hydrogen peroxide (H 2 O 2 ), which can be easily detected by amperometric and photometric methods [5][6][7][8][9][10]. In particular, choline in biochemical and clinical applications is determined by HPLC separation techniques in many clinical laboratories [11][12][13][14].…”

Section: Inductionmentioning

confidence: 99%

Enzymatic flow injection method for rapid determination of choline in urine with electrochemiluminescence detection

Jin

Muroga

Takahashi

et al. 2010

Bioelectrochemistry

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In order to determine trace choline in human urine, a flow injection analysis (FIA) system has been developed by coupling of an enzyme reactor with an electrochemiluminescence (ECL) detector. The enzyme reactor is prepared by covalently immobilizing of choline oxidase (ChOx) onto the aminopropyl-controlled pore glass beads, which are then carefully packed into a micro column. The enzyme reactor catalyzes the production of hydrogen peroxide that is in direct proportion to the concentration of choline. In this study, the enzymatically produced hydrogen peroxide was detected by an ECL detector positioned at the down stream of enzyme reactor based on the luminol/H 2 O 2 ECL system. Under the optimized condition, the enzymatic FIA/ECL provided high sensitivity for the determination of choline with the detection limit as low as 0.05 M (absolute detection limit was at sub pmol level). The method was successfully applied in the determination of choline in the samples of human urine, and the analytical results were in good agreement with those obtained by using the microbore HPLC with immobilized enzyme reactor-electrochemical detection system.

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Section: Inductionmentioning

confidence: 99%

Enzymatic flow injection method for rapid determination of choline in urine with electrochemiluminescence detection

Jin

Muroga

Takahashi

et al. 2010

Bioelectrochemistry

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“…PBP for different ligands have been found, but the question to solve is what occurs with those ligands for which a molecular switch cannot be found. Strategies signal to analyte concentration [64]:…”

Section: Discussionmentioning

confidence: 99%

“…Figure 4a indicates how the reduced form of the GOx (represented as GOx.H 2 ) changes during the reaction using different analyte concentrations. This is observed, for example, for reactions of cholesterol oxidase (COx) [63] and choline oxidase (ChOx) [64]. Type B The rate of regeneration is faster than that of oxidation (K M is high).…”

Section: Generation Of the Analytical Signalmentioning

confidence: 93%

“…Unlike the type B methods, in Type A it is not necessary for the O 2 to be fully consumed before obtaining the signal; it is, moreover, better that the analyte concentration remains < [O 2 ] 0 for faster regeneration, so lower analyte concentrations (compared with type B) can be determined. For example, choline [64] and cholesterol [63] have been determined in the range from 0.5 to 50 μmol L −1 and from 0.013 to 0.2 mmol L −1 , respectively. One of the most interesting applications of the flavoenzyme fluorescence (tryptophan or attached fluorophore)-based method is the simultaneous determination of species in the same measurement.…”

Section: Other Flavoproteinsmentioning

confidence: 99%

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Reagentless fluorescent biosensors based on proteins for continuous monitoring systems

et al. 2012

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There is a lack of commercially available efficient and autonomous systems capable of continuous monitoring of (bio)chemical data for clinical, environmental, food, or industrial samples. The weakest link in the design of these systems is the (bio)chemical receptor (bCR). The bCR should have transducer ability, the recognition event should be a single reaction, and the bCR should be easily regenerated. Transport proteins and enzymes are well placed as bCR for optical continuous monitoring systems (OCMS). In this paper we review quantitative aspects and the main transducer strategies which have been developed for transport proteins, using periplasmic binding proteins (linking an environmentally sensitive fluorophore or FRET between two fluorophores) and concanavalin A (competitive reversible assays) as representative examples. Efficient immobilization systems and implementation in OCMS are also reviewed. Some kinds of enzymes can fulfil the necessary requirements to be appropriate bCR. Strategies using flavoenzymes chemically modified with fluorophores can be successfully implemented in OCMS and they are, in our opinion, the most appropriate option.

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“…from the intrinsic composition of the protein, such as the general UV fluorescence (due to aminoacids, mainly tryptophan [2]) or the specific visible fluorescence (FAD-containing proteins or the green fluorescence protein [3]), or after chemical or genetic modification or both [4][5][6], the periplasmic binding proteins being the most popular example [7]. Finally, molecular absorption properties are now being exploited for analytical uses, the most important example being the metalloproteins.…”

Section: Introductionmentioning

confidence: 99%

Uric acid determination using uricase and the autotransducer molecular absorption properties of peroxidase

Sanz

Marcos

Galbán

2008

Analytica Chimica Acta

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Choline determination based on the intrinsic and the extrinsic (chemically modified) fluorescence of choline oxidase

Cited by 16 publications

References 18 publications

Enzymatic flow injection method for rapid determination of choline in urine with electrochemiluminescence detection

Enzymatic flow injection method for rapid determination of choline in urine with electrochemiluminescence detection

Reagentless fluorescent biosensors based on proteins for continuous monitoring systems

Uric acid determination using uricase and the autotransducer molecular absorption properties of peroxidase

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