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Soldatkin O.O.,NASU Institute of Molecular Biology and Genetics | Soldatkin O.O.,Taras Shevchenko National University | Shelyakina M.K.,NASU Institute of Molecular Biology and Genetics | Arkhypova V.N.,NASU Institute of Molecular Biology and Genetics | And 10 more authors.
Nanoscale Research Letters | Year: 2015

A number of potentiometric biosensors based on coimmobilization of enzymes with different types of zeolite on pH-ion-sensitive field-effect transistor (ISFET) have been developed. Their working characteristics have been determined and compared. It was shown that clinoptilolite and zeolite Beta polymorph A (BEA) are more promising for creating biosensors than zeolite A. Changing the concentration of zeolite BEA in membranes, it is possible to extend the biosensor linear measurement range. The two-layer method of deposition of the enzyme with clinoptilolite was found to provide a significant increase in the biosensor sensitivity to substrates, whereas thermal modification of the zeolite BEA crystals can improve analytical characteristics of potentiometric biosensors for detection of toxic substances. These results show that it is possible to regulate the ISFET characteristics for different enzyme-based biosensors by tailoring the electrode surfaces via different zeolites. This makes zeolites strong candidates for integration into biosensors as ISFET modifiers. © 2015, Soldatkin et al.; licensee Springer. Source

Wang L.-J.,Institute of Analytical science | Wang L.-J.,Xian Jiaotong University | Tang Y.-H.,Institute of Analytical science | Liu H.-L.,Institute of Analytical science | Yi J.-F.,Institute of Analytical science
Academic Journal of Xi'an Jiaotong University | Year: 2010

Objective: To develop a rapid, simple and sensitive chemiluminescence method for the determination of three β-blockers (bisoprolol, atenolol and propranolol). Methods: The chemiluminescence of cerium (IV)-sulfite system was obviously sensitized by adding anyone of three β-blockers in acid media. A new chemiluminescence method was set up by combining with flow-injection technique and used to determine the three β-blockers. Results: Good linear ranges were obtained at the concentrations of 2.0×10-7g/mL-4. 0×10-5g/mL, 1.0×10-7g/mL-3.0×10 -5g/mL and 7.0×10-7g/mL-1.0×10 -5g/mL, respectively, with the detection limits of 5.0×10 -8g/mL, 7.0×10-8g/mL and 5.0×10 -8g/mL (S/N= 3), respectively, and the relative standard deviations for 11 times consecutive injections of 1.0×10-5g/mL bisoprolol, atenolol and propranolol were 3.57%, 2.21% and2.26%, respectively. Conclusion: The developed method is sensitive, accurate, rapid and of low cost. And it can be applied to determine bisoprolol, atenolol and propranolol in pharmaceutical preparations. Source

Kucherenko I.,NASU Institute of Molecular Biology and Genetics | Kucherenko I.,Taras Shevchenko National University | Kucherenko I.,Institute of Analytical science | Soldatkin O.,NASU Institute of Molecular Biology and Genetics | And 10 more authors.
Nanoscale Research Letters | Year: 2015

In this work, the method of enzyme adsorption on different zeolites and mesoporous silica spheres (MSS) was investigated for the creation of conductometric biosensors. The conductometric transducers consisted of gold interdigitated electrodes were placed on the ceramic support. The transducers were modified with zeolites and MSS, and then the enzymes were adsorbed on the transducer surface. Different methods of zeolite attachment to the transducer surface were used; drop coating with heating to 200°C turned out to be the best one. Nanozeolites beta and L, zeolite L, MSS, and silicalite-1 (80 to 450 nm) were tested as the adsorbents for enzyme urease. The biosensors with all tested particles except zeolite L had good analytical characteristics. Silicalite-1 (450 nm) was also used for adsorption of glucose oxidase, acetylcholinesterase, and butyrylcholinesterase. The glucose and acetylcholine biosensors were successfully created, whereas butyrylcholinesterase was not adsorbed on silicalite-1. The enzyme adsorption on zeolites and MSS is simple, quick, well reproducible, does not require use of toxic compounds, and therefore can be recommended for the development of biosensors when these advantages are especially important. © 2015, Kucherenko et al.; licensee Springer. Source

He Y.,Institute of Analytical science | Zheng J.,Institute of Analytical science | Dong S.,Institute of Analytical science
Analyst | Year: 2012

A facile, one-pot ultrasonic electrochemical method to synthesize hierarchical cobalt (Co)-nanoflowers on petalage-like graphene (GE) was developed. The hybrid microstructures were successfully evaluated as a new material for highly sensitive determination of hydrazine (N 2H 4). Scanning electron microscopic measurements displayed that the synthesized Co-GE exhibited a related hierarchical structure of a petalage-like GE homogeneous distribution as a matrix for the growth of smooth nanosheets-assembled Co nanoflowers. Co-GE was confirmed by energy dispersive X-ray spectrograms. Electrochemical methods were adopted to characterize the sensing properties of Co-GE towards the electrocatalytic oxidation of N 2H 4 at 0.15 V in 0.1 M pH 7.0 sodium phosphate buffered saline. The sensor displayed a broad linearity of 0.25-370 μM and 370 μM to 2.2 mM with a relatively low detection limit of 0.1 μM (S/N = 3) and a response time of less than 3 s. Furthermore, the sensor showed outstanding sensitivity and reproducibility. © 2012 The Royal Society of Chemistry. Source

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