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

Abstract

Humans are generally exposed to a variety of pollutions present in the air they breathe, the food they eat or in the water they drink. Some of the most dangerous pollutions are metals and heavy metals. These are naturally occurring substances which are harmless when present in the environment at low levels. However, due to many pollutants such as industry processes or war activities, the heavy metal concentration can exceed the limit of tolerance and become very toxic for the natural environment and living organisms in it, including humans. Unlike organic pollutants, the heavy metals (as ions and as particulate matter) once introduced into the environment cannot be biodegraded and remain there indefinitely. By rainfall these pollutants can be partially transferred from air or soil into the rivers and drinking water sources, where they accumulate in even higher toxic levels. The high concentrations of heavy metals in contaminated natural water reservoirs have an impact on the microbial community composition which resides there. This type of water pollution can cause the changes in life cycles of natural bacterial populations, influencing their metabolic processes and proliferation. The presence of pathogens in water is normally indirectly determined by the testing for “indicator organism” such as coliform bacteria. Coliforms are usually present in larger numbers in contaminated water and at the same time they are indicators of whether other pathogenic bacteria are present, too. In crisis situations, like war or some natural disasters, where trusted sources of drinking water are not available anymore, the military and residents of affected areas are forced to use some alternative water resources that cannot be tested for their microbial or metal contamination properly. Therefore, the existence of some fast test that would detect not only dangerous bacterial pathogens in water, but also the presence of metals and heavy metals as well, would be of great help and importance for the human health. Even though the number of pathogens can be drastically reduced by the boiling of water, the heavy metals are not destroyed by high temperature. Hence the main objective of our work was to optimize the biosensor chip for microbial detection in contaminated water that would serve at the same time as an indicator for the chemical composition of the water, such as presence of metals and heavy metals, with potential to be used as a novel test tool in public health.