Assessing Microbial Water Quality: Electroanalytical Approaches to the Detection of Coliforms

Coliforms have a long history of being used as indicator species for assessing the quality of water but it is only in recent decades that there has been sustained international effort to develop the technologies that can enable their routine on-site analysis within low income communities. Electrochemical techniques possess numerous advantages in relation to portable detection and, while a large number of approaches have been investigated, the use of galactosidase and glucuronidase assays predominate. The latter form the basis of a multitude of commercial coliform test kits based on colorimetric analysis but there has been considerable interest in translating the methodologies to electrochemical formats. While the latter is at an early developmental stage, the aims of the review have been to assess the technological evolution of such systems and to highlight the challenges likely to be faced in providing viable sensing solutions for use in monitoring water quality within rural communities dependent on improved water sources.