Covalent immobilization of cholesterol esterase and cholesterol oxidase on polyaniline films for application to cholesterol biosensor

2006 ◽  
Vol 568 (1-2) ◽  
pp. 126-132 ◽  
Author(s):  
Suman Singh ◽  
Pratima R. Solanki ◽  
M.K. Pandey ◽  
B.D. Malhotra
Keyword(s):  
Cholesterol Oxidase ◽  
Covalent Immobilization ◽  
Cholesterol Esterase ◽  
Polyaniline Films ◽  
Cholesterol Biosensor

Covalent immobilization of cholesterol oxidase and poly(styrene-co-acrylic acid) magnetic microspheres on polyaniline films for amperometric cholesterol biosensing

2013 ◽  
Vol 5 (6) ◽  
pp. 1392 ◽  
Author(s):  
Nguyen Le Huy ◽  
Nguyen Thi My Thuy ◽  
Nguyen Hai Binh ◽  
Nguyen Ngoc Thinh ◽  
Mai Thu Trang ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Cholesterol Oxidase ◽  
Covalent Immobilization ◽  
Magnetic Microspheres ◽  
Polyaniline Films

scholarly journals An Electrochemical Cholesterol Biosensor Based on A CdTe/CdSe/ZnSe Quantum Dots—Poly (Propylene Imine) Dendrimer Nanocomposite Immobilisation Layer

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3368 ◽  
Author(s):  
Kefilwe Mokwebo ◽  
Oluwatobi Oluwafemi ◽  
Omotayo Arotiba
Keyword(s):  
Quantum Dots ◽  
Modified Electrode ◽  
Cholesterol Oxidase ◽  
Shell Growth ◽  
Modified Electrodes ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Poly Propylene ◽  
Cholesterol Biosensor

We report the preparation of poly (propylene imine) dendrimer (PPI) and CdTe/CdSe/ZnSe quantum dots (QDs) as a suitable platform for the development of an enzyme-based electrochemical cholesterol biosensor with enhanced analytical performance. The mercaptopropionic acid (MPA)-capped CdTe/CdSe/ZnSe QDs was synthesized in an aqueous phase and characterized using photoluminescence (PL) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), X-ray power diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy. The absorption and emission maxima of the QDs red shifted as the reaction time and shell growth increased, indicating the formation of CdTe/CdSe/ZnSe QDs. PPI was electrodeposited on a glassy carbon electrode followed by the deposition (by deep coating) attachment of the QDs onto the PPI dendrimer modified electrode using 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) as a coupling agent. The biosensor was prepared by incubating the PPI/QDs modified electrode into a solution of cholesterol oxidase (ChOx) for 6 h. The modified electrodes were characterized by voltammetry and impedance spectroscopy. Since efficient electron transfer process between the enzyme cholesterol oxidase (ChOx) and the PPI/QDs-modified electrode was achieved, the cholesterol biosensor (GCE/PPI/QDs/ChOx) was able to detect cholesterol in the range 0.1–10 mM with a detection limit (LOD) of 0.075 mM and sensitivity of 111.16 μA mM−1 cm−2. The biosensor was stable for over a month and had greater selectivity towards the cholesterol molecule.

scholarly journals A simple method for the determination of the cholesterol esterase activity.

2013 ◽  
Vol 60 (3) ◽  
Author(s):  
Agnieszka Ewa Stępień ◽  
Mykhailo Gonchar
Keyword(s):  
Human Serum ◽  
Esterase Activity ◽  
Cholesterol Oxidase ◽  
Cholesterol Esterase ◽  
Cholesterol Esters ◽  
Simple Method ◽  
Bacterial Enzyme ◽  
Low Costs ◽  
Hydrolysis Of

The proposed method determines the activity of cholesterol esterase (CEH) and takes advantage of its ability to catalyze the hydrolysis of cholesterol esters naturally present in human serum. The assay is based on Allain's method of spectrophotometric determination of cholesterol by means of cholesterol oxidase, peroxidase, but using 3,5-dichloro-dihydroxybenzenesulfonic acid (DHBS) as phenolic chromogen and human serum as a source of substrate for the CEH as a novelty. Furthermore, it is characterized by low costs and high precision. It can be employed to control the activity of CE preparations used for the preparation of enzymatic kits for the determination of cholesterol or for screening of potential bacterial enzyme producers.

scholarly journals Enzymatic Reactions in a Lab-on-Valve System: Cholesterol Evaluations

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2890 ◽  
Author(s):  
Jucineide S. Barbosa ◽  
Marieta L.C. Passos ◽  
M. das Graças A. Korn ◽  
M. Lúcia M.F.S. Saraiva
Keyword(s):  
Cholesterol Oxidase ◽  
Analytical Tool ◽  
Cholesterol Esterase ◽  
Sequential Injection Analysis ◽  
Enzymatic Reactions ◽  
Waste Generation ◽  
Serum Samples ◽  
Real Samples ◽  
Reagent Consumption ◽  
Alternative Methodology

The micro sequential injection analysis / lab-on-valve (µSIA-LOV) system is a miniaturized SIA system resulting from the implementation of a lab-on-valve (LOV) atop of the selection valve. It integrates the detection cell and the sample processing channels into the same device, promoting the reduction of reagent consumption and waste generation, the improvement of the versatility, and the reduction of the time of analysis. All of these characteristics are really relevant to the implementation of enzymatic reactions. Additionally, the evaluation of cholesterol in serum samples is widely relevant in clinical diagnosis, since higher values of cholesterol in human blood are actually an important risk factor for cardiovascular problems. An automatic methodology was developed based on the µSIA-LOV system in order to evaluate its advantages in the implementation of enzymatic reactions performed by cholesterol esterase, cholesterol oxidase and peroxidase. Considering these reactions, the developed methodology was also used for the evaluation of cholesterol in human serum samples, showing reliable and accurate results. The developed methodology presented detection and quantification limits of 1.36 and 4.53 mg dL−1 and a linear range up to 40 mg dL−1. This work confirmed that this µSIA-LOV system is a simple, rapid, versatile, and robust analytical tool for the automatic implementation of enzymatic reactions performed by cholesterol esterase, cholesterol oxidase, and peroxidase. It is also a useful alternative methodology for the routine determinations of cholesterol in real samples, even when compared with other automatic methodologies.

An enzymatic assay for determining free and total cholesterol in tissue.

1978 ◽  
Vol 24 (3) ◽  
pp. 433-435 ◽  
Author(s):  
J L De Hoff ◽  
L M Davidson ◽  
D Kritchevsky
Keyword(s):  
Total Cholesterol ◽  
Rat Liver ◽  
Ferric Chloride ◽  
Cholesterol Oxidase ◽  
Enzymatic Assay ◽  
Cholesterol Esterase ◽  
Enzymatic Method ◽  
Liver Lipids

Abstract We describe a method for determining free and total cholesterol in extracts of rat-liver lipids by use of a cholesterol esterase/cholesterol oxidase enzymatic kit (Boehringer Mannheim Corp). The lipids are solubilized (as micelles) directly into the aqueous reagent mixture. Results of the enzymatic method correlate well with those obtained by an acid/ferric chloride assay of digitonin precipitates of the extracts. The enzymatic assay of free and total cholesterol in tissue offers advantages of simplicity over previously used methods.

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