ABSTRACT
Increasing scientifi c and social concern in environmental pollution control, especially on water quality control, has recently led to a growing number of initiative and legislative actions being extensively enacted in this area. To monitoring the water quality with rapidity, simplicity, sensitivity and easy maintenance is very important. Analytical instrumental methods, including HPLC, GC-MS and LC-MS, require complex pretreatment and analysis protocols. Biomonitoring methods using vertebrates or fi sh have drawbacks of long detection time, as well as the ethic and moral issue. The need of portable and inexpensive systems for environmental monitoring has stimulated the development of new methods. In recent years, the use of whole microorganism cell as the biological sensing element has demonstrated great potential as an alternative to the conventional analytical methods. Due to the excellent performance of microbial biosensors in environmental monitoring, numerous microbial biosensors by measuring light, fl uorescence, color or electrochemical signals have been developed. A BOD determination with photodiode was developed based on reading the luminescence intensity of luminous bacterium Photobacterium phosphoreum in wastewater. The fl uorescence intensity of microbial communities excited by UV at 430 nm was in proportion to the assimilable organic contaminants amount, based on which the toxicity value can be measured by the difference of fl uorescence intensity. Despite the good sensitivity and stability of these methods based on photometric or fl uorescence techniques, some compounds could interfere with the performance during the test procedure. The electrochemical measurements are of particular interests for in situ measurements, due to their convenience to manipulate, anti-interference ability and short response time.
