The paper presents results of research concerning possibilities of applications of reporter-genes based microorganisms, including the selective presentation of defects and advantages of different new scientific achievements of methodical solutions in genetic system constructions of biosensing elements for environmental research. The most robust and popular genetic fusion and new trends in reporter genes technology – such as LacZ (β-galactosidase), xylE (catechol 2,3-dioxygenase), gfp (green fluorescent proteins) and its mutated forms, lux (prokaryotic luciferase), luc (eukaryotic luciferase), phoA (alkaline phosphatase), gusA and gurA (β-glucuronidase), antibiotics and heavy metals resistance are described. Reporter-genes based biosensors with use of genetically modified bacteria and yeast successfully work for genotoxicity, bioavailability and oxidative stress assessment for detection and monitoring of toxic compounds in drinking water and different environmental samples, surface water, soil, sediments.
Sol-gel derived silica possess many promising features, including low-temperature preparation procedure, porosity, chemical and physical stability. Applications exploiting porous materials to encapsulate sensor molecules, enzymes and many other compounds, are developing rapidly. In this paper some potential applications, with emphasis on biomedical and environmental ones, are reviewed. The material preparation procedure is described and practical remarks on silica-based sol-gels are included. It is reported that sol-gels with entrapped various molecules may be used in construction of implants and coatings with bioactive properties. It is shown how to exploit the sol-gel production route for construction of sol-gel coated fiberoptic applicators for lasertherapy. The applications of bioactive materials are discussed, as well. It is demonstrated that it is possible to immobilize photosensitive compounds in sol-gel matrix without loosing their photoactivity. Some examples of sol-gel based biosensors are demonstrated, as well, showing their potential for detecting various gases, toxic substances, acidity, humidity, enzymes and biologically active agents.
Biosensors are a crucial part of most of bioanalytical diagnostic devices and systems. Due to semiconductor technologies, a great progress in diminution of costs and miniaturisation as well as an increased reliability of these devices was achieved. Application of molecular and biological techniques in the detection process has contributed to a real increase in sensitivity, selectivity, the detection limit and the number of analytes to be detected. Different transducers of chemical parameters into electrical output signals are applied in these devices. Electrochemical principles, both potentiometric and amperometric, are opted for due to their simplicity of application and extremely low costs of such biosensors. Ion sensitive field effect transistors (ISFETs) may be easily integrated into the required electronics, resulting in their miniaturisation. Further miniaturisation may be attained by development of miniaturised total analytical systems (uTAS). To ensure competitive parameters of these biosensors, optimal methods of immobilisation of biochemical receptors (ionophores, enzymes, antibodies, etc.) should be developed. A review of the work by the authors related to these problems is presented in the article.