Biosensor Chip for Monitoring of Water Pollution as Novel Test Tool in Public Health: Proof of Principle

Humans are generally exposed to a variety ofpollutions present in the air they breathe, the food they eat or inthe water they drink. Some of the most dangerous pollutions aremetals and heavy metals. These are naturally occurringsubstances which are harmless when present in the environmentat low levels. However, due to many pollutants such as industryprocesses or war activities, the heavy metal concentration canexceed the limit of tolerance and become very toxic for the naturalenvironment and living organisms in it, including humans. Unlikeorganic pollutants, the heavy metals (as ions and as particulatematter) once introduced into the environment cannot bebiodegraded and remain there indefinitely. By rainfall thesepollutants can be partially transferred from air or soil into therivers and drinking water sources, where they accumulate in evenhigher toxic levels. The high concentrations of heavy metals incontaminated natural water reservoirs have an impact on themicrobial community composition which resides there. This typeof water pollution can cause the changes in life cycles of naturalbacterial populations, influencing their metabolic processes andproliferation. The presence of pathogens in water is normallyindirectly determined by the testing for “indicator organism” suchas coliform bacteria. Coliforms are usually present in largernumbers in contaminated water and at the same time they areindicators of whether other pathogenic bacteria are present, too.In crisis situations, like war or some natural disasters, wheretrusted sources of drinking water are not available anymore, themilitary and residents of affected areas are forced to use somealternative water resources that cannot be tested for theirmicrobial or metal contamination properly. Therefore, theexistence of some fast test that would detect not only dangerousbacterial pathogens in water, but also the presence of metals andheavy metals as well, would be of great help and importance forthe human health. Even though the number of pathogens can bedrastically reduced by the boiling of water, the heavy metals arenot destroyed by high temperature. Hence the main objective ofour work was to optimize the biosensor chip for microbial detection in contaminated water that would serve at the same timeas an indicator for the chemical composition of the water, such aspresence of metals and heavy metals, with potential to be used as anovel test tool in public health.