MEMS Biosensor for In Situ Drinking Water Analysis

The occurrence of causative agents such as Cryptosporidium parvum and other pathogens in water supplies presents a critical issue. Transmitted through water and animals, these organisms provide a reservoir of infection, which results in the excretion of the environmentally stable cysts or oocysts that are impervious to inactivation by many drinking water disinfectants. Cryptosporidium infections are particularly problematic for immuno-compromised individuals because drug therapy to control or eliminate this organism from a human host is not yet available. The method currently used for detection of these pathogenic microorganisms at the water source is not only laborious and time consuming, but often inefficient in accurately recovering and identifying waterborne pathogens. Various alternative technologies have been investigated; however, none to date have been able to provide the possibility of rapid, sensitive, and low-cost field testing. The use of nucleic acid based detection technologies, such as DNA probes, provides the greatest potential for highly specific and sensitive detection of potentially hazardous biological agents. The most promising approach to developing the ideal biosensor is microfabrication of identification systems that mimic diagnostic schemes utilized in microbiology laboratories to detect and identify specific microbial agents. Although there is much activity in this area, most efforts suffer from the inability to properly marry microfabrication technology with the molecular biology required for sensitive and specific detection.