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Martínez M Hilding-Ohlsson A Viale AA Cortón E 《Journal of biochemical and biophysical methods》2007,70(3):455-464
We describe a new, faster and convenient method to study some metabolic characteristics - by the successful application of immobilized yeast cells (S. cerevisiae) in a microbial biosensor-like device. Microbial biosensors consist of microorganisms immobilized on the surface of a membrane or in a gel, in close contact with a transducer. Almost all works published to date have used biosensors for analyses in which a concentration-related property of the external medium is measured. A different approach is presented here; we have successfully used S. cerevisiae and a carbon dioxide electrode as the main components of a biosensor-like device, used as a proof of concept, for a system useful to characterize metabolic parameters of the microbial cells immobilized on a carbon dioxide electrode. The biosensor-like device we are presenting allows us to calculate Michaelis-Menten parameters related to the kinetics of transport and degradation of several carbohydrates (i.e., glucose, fructose, galactose, sucrose and xylose, with K(m(app)) of 6.0, 5.8, 0.9, 2.0, and 147 mM, respectively), and the study of the kinetics of expression of non-constitutive proteins related to the transport and degradation of galactose. 相似文献
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Elements of biosensor construction 总被引:3,自引:0,他引:3
The diverse configurations observed in amperometric biosensors can be attributed to the manipulation of several interrelated elements in the construction of these devices. This article highlights these elements and identifies approaches taken and the factors influencing the choice of the approaches. The results of a systematic literature review over a 2.5-year period (18 May 1992–21 November 1994) encompassing all of the elements in biosensor construction are used to evaluate the prevalence, and hence, acceptance of recent approaches with critical analysis applied to certain techniques. Future trends are predicted and possible directions discussed. 相似文献
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A. Alberti Dante Macciantelli Stefano Predieri Federica Rossi 《Trees - Structure and Function》2000,14(6):312-315
Differently aged needles from a Pinus nigra Arnold tree growing in a typical urban area have been examined by means of electron paramagnetic resonance (EPR) spectroscopy,
and the variation of the observed six-line Mn (II) signal was monitored for 1 year. An inverse trend has been established
between the photosynthetic efficiency of the plant and the measured content of Mn (II). The possibility of using EPR spectroscopy
in studying ageing and in assessing stress situations in plants is considered.
Received: 23 April 1999 / Accepted: 13 January 2000 相似文献
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生物传感器的应用研究进展 总被引:9,自引:0,他引:9
生物传感器是一门由生物、化学、物理、医学、电子技术等多种学科互相渗透成长起来的高新技术 ,是一种将生物感应元件的专一性与一个能够产生和待测物浓度成比例的信号传导器结合起来的分析装置。由于其具有选择性好、灵敏度高、分析速度快、成本低、能在复杂体系中进行在线连续监测的特点 ,已在生物、医学、环境监测、食品、医药、及军事医学等领域显示出广阔的应用前景 ,引起了世界各国的极大关注。综述了生物传感器的基本原理、分类、特点及在环境监测、食品分析、生物医学和军事上的应用 ,并对其发展前景进行了展望。 相似文献
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Microfluidic cell culture chips allow to perform assays of small-volume samples rapidly and reproducibly. Most of these chips are made of poly(dimethylsiloxane) (PDMS), which is a flexible, durable, transparent and inexpensive polymer that can be easily applied to fabrication of microstructures by photolithography and replica molding. However, not many cells are able to grow on unmodified PDMS because the cells need appropriate scaffolds on the surface. Here we report surface modification of a PDMS substrate with a microarray of extracellular matrix (ECM) for on-chip cell culture. The ECM proteins collagen and fibronectin were covalently immobilized on an 8 x 8 microarray format by micropatterned UV-induced graft polymerization through a photomask and dehydration-condensation reaction through a microfabricated stencil. Identical spots of ECMs were successfully formed and the geometry of the spots accurately corresponded to the micropattern of the photomask and stencil. We demonstrate the culture of CHO-K1 cells on the ECM microarray chip. Cells proliferated on the fibronectin spots during the 2-day culture. 相似文献
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Novel chitin and chitosan nanofibers in biomedical applications 总被引:2,自引:0,他引:2
Chitin and its deacetylated derivative, chitosan, are non-toxic, antibacterial, biodegradable and biocompatible biopolymers. Due to these properties, they are widely used for biomedical applications such as tissue engineering scaffolds, drug delivery, wound dressings, separation membranes and antibacterial coatings, stent coatings, and sensors. In the recent years, electrospinning has been found to be a novel technique to produce chitin and chitosan nanofibers. These nanofibers find novel applications in biomedical fields due to their high surface area and porosity. This article reviews the recent reports on the preparation, properties and biomedical applications of chitin and chitosan based nanofibers in detail. 相似文献
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Behrouz Golichenari Rahim Nosrati Aref Farokhi-Fard Mahdi Faal Maleki Seyed Mohammad Gheibi Hayat Kiarash Ghazvini 《Critical reviews in biotechnology》2013,33(8):1056-1077
AbstractEarly detection of tuberculosis (TB) reduces the interval between infection and the beginning of treatment. However, commercially available tests cannot discriminate between BCG-vaccinated healthy persons and patients. Also, they are not suitable to be used for immunocompromised persons. In recent years, biosensors have attracted great attention due to their simple utility, accessibility, and real-time outputs. These sensors are increasingly being considered as pioneering tools for point-of-care diagnostics in communities with a high burden of TB and limited accessibility to reference laboratories. Among other types of biosensors, the electrochemical sensors have the advantages of low-cost operation, fast processing, simultaneous multi-analyte analyzing, operating with turbid samples, comparable sensitivity and readily available miniaturization. Electrochemical biosensors are sub-divided into several categories including: amperometric, impedimetric, potentiometric, and conductometric biosensors. The biorecognition element in electrochemical biosensors is usually based on antibodies (immunosensors), DNAs or PNAs (genosensors), and aptamers (aptasensors). In either case, whether an interaction of the antigen–antibody/aptamer or the hybridization of probe with target mycobacterial DNA is detected, a change in the electrical current occurs that is recorded and displayed as a plot. Therefore, impedimetric-based methods evaluate resistance to electron transfer toward an electrode by a Nyquist plot and amperometric/voltammetric-based methods weigh the electrical current by means of cyclic voltammetry, square wave voltammetry, and differential pulse voltammetry. Electrochemical biosensors provide a promising scope for the new era of diagnostics. As a consequence, they can improve detection of Mycobacterium tuberculosis traces even in attomolar scales. 相似文献