Biosensors

Two decades of research into biosensors has been accelerated recently by the commercial potential offered by biotechnology. New developments in biosensor technology in which a biologically sensitive material is immobilized in intimate contact with a suitable potentiometric, amperometric, optical or other transducer are described. It is expected that some of these devices will be commercialized in 1984.     

Biosensors

Biosensors are analytical devices that respond selectively to analytes in an appropriate sample and convert their concentration into an electrical signal via a combination of a biological recognition system and an electrochemical, optical or other transducer. Such devices will find application in medicine, agriculture, environmental monitoring and the bioprocessing industries. The last few years have seen great advances in the design of sensor architectures, the marriage of biological systems with monolithic silicon and optical technologies, the development of effective electron-transfer systems and the configuration of direct immunosensors. Recent progress in these areas has already led to the introduction of new-generation biosensors into the competitive diagnostics market place.     

压电生物传感

本文提出：压电生物传感器应分为两大类型,即质量响应型和非质量响应型。探讨了这两类生物传感器的理论基础。叙述了它们在酶学、免疫学、微生物学、ＤＮＡ杂化、内毒素检测、气相传感、仿生学和血液流变学中的应用。     

Biosensors and bioelectrochemistry

This review describes recent developments in the field of biosensors and bioelectrochemistry. Nanoparticles have been used to improve sensor performance and to develop biosensors based on new detection principles. Their use has extended into all areas of biosensor and bioelectrochemistry research. Other active areas of biosensor development include DNA sensing, immunosensing, direct electron transfer between an electrode and a redox protein or enzyme, and in vivo sensors.     

Biosensors in process control

Improvement in bioprocess control will require development of monitors for a wide range of cell-growth and downstream-process parameters. These requirements are examined in terms of the development and application of biosensor devices and physical measurement techniques. Acoustic, dielectric and laser light scattering techniques are discussed primarily as monitors and analysers for biomass parameters. Developments with biosensor devices are discussed in terms of their application in membrane sampling-flow analysis probes and the potential of more direct biosensing principles.     

Biosensors: recent trends

One of the major bottlenecks in automation and process control of industrial bioprocesses is the lack of suitable sensing devices to accurately measure the concentrations of biomolecules. The measurement of ions (e.g., H⁺, NH₄⁺) and gases (e.g., O₂, CO₂, NH₃) using standard ion-selective and gas sensing electrodes respectively, is well established. Chemical analysis of biomolecules off-line is generally unreliable, labour intensive and may lead to contamination of the biological systems. Problems of maintaining sterile conditions are especially important when dealing with slow growing mammalian or plant cells in culture. Active research in the development of biosensors for monitoring fermentation processes, food production and pollution control, and for medical and veterinary applications is currently underway. This paper reviews recent approaches toward the development of biosensors which involve a biochemical interaction to measure the concentrations of biomolecules, primarily for the on-line monitoring and control of fermentation processes.     

Biosensors for process monitoring

Summary A short review about the biosensor research activities for bioprocess monitoring in the F.R.G. after its reunification is given. The principles of biosensor applications are presented. In situ sensors and sensors based on the principles of flow injection analysis are studied. Some applications of a four-channel enzyme thermistor, bio-field effect transistors, and immunoanalysis systems for real process monitoring are presented.     

Biosensors for environmental monitoring

Increasing environmental legislation which controls the release and the levels of certain chemicals in the environment has created a need for reliable monitoring of these substances in air, soil and especially water. Conventional analytical techniques, although highly precise, suffer from the disadvantages of high cost, the need for trained personnel and the fact that they are mostly laboratory bound. Biosensors because of their specificity, fast response times, low cost, portability, ease of use and a continuous real time signal, can present distinct advantages in certain cases. Their biological base makes them ideal for toxicological measurements which are suited for health and safety applications. Over the last 3-4 years there has been an increase in the number of publications concerning biosensors for environmental monitoring, especially in the field of pesticide measurements.This paper reviews some of the more important developments over the past 3-4 years.     

Biosensors for heavy metals

A biosensor is an analytical device that consists of an immobilized biocomponent in conjunction with a transducer, and represents a synergistic combination of biotechnology and microelectronics. This review summarizes the use of biosensors for detecting and quantifying heavy metal ions. Heavy metal contamination is of serious concern to human health since these substances are non-biodegradable and retained by the ecological system. Conventional analytical techniques for heavy metals (such as cold vapour atomic absorption spectrometry, and inductively coupled plasma mass spectrometry) are precise but suffer from the disadvantages of high cost, the need for trained personnel and the fact that they are mostly laboratory bound. Biosensors have the advantages of specificity, low cost, ease of use, portability and the ability to furnish continuous real time signals. The analysis of heavy metal ions can be carried out with biosensors by using both protein (enzyme, metal-binding protein and antibody)-based and whole-cell (natural and genetically engineered microorganism)-based approaches.Published online: March 2005     

Plants as Environmental Biosensors

Plants are continuously exposed to a wide variety of perturbations including variation of temperature and/or light, mechanical forces, gravity, air and soil pollution, drought, deficiency or surplus of nutrients, attacks by insects and pathogens, etc., and hence, it is essential for all plants to have survival sensory mechanisms against such perturbations. Consequently, plants generate various types of intracellular and intercellular electrical signals mostly in the form of action and variation potentials in response to these environmental changes. However, over a long period, only certain plants with rapid and highly noticeable responses for environmental stresses have received much attention from plant scientists. Of particular interest to our recent studies on ultra fast action potential measurements in green plants, we discuss in this review the evidence supporting the foundation for utilizing green plants as fast biosensors for molecular recognition of the direction of light, monitoring the environment, and detecting the insect attacks as well as the effects of pesticides, defoliants, uncouplers, and heavy metal pollutants.Key Words: plant signaling, plant electrophysiology, action potential, biosensor     

Biosensors and molecular imaging

The increase in the understanding of the physical and functional properties of the biological material, from the cellular level down to single molecules, owes its success to the development of suitable high-sensitivity platforms to image the biomaterial and analyze its response to specific stimuli. Imaging has indeed reached molecular capabilities, thanks to optical or magnetic markers [1], to the atomic force microscopy (AFM) in surface reconstruction [2], and is nearing success in three-dimensional (3-D) reconstruction thanks to X-ray holography [3].     

DNA生物传感器进展

近几年来,酶传感器、免疫传感器及微生物传感器等发展较为成熟,而DNA生物传感器的研究相对较少.文章从核酸杂交的原理出发介绍了DNA生物传感器的工作原理,举例说明了电化学、光学和声学等几种典型的DNA生物传感器,指出了其固有的优缺点,肯定了DNA传感器发展前景.