Portable electronic system for fast detection of bacteria lactase fermentation in water samples

The detection of the presence of bacteria in water is essential to determine their use and prevent environmental and health problems. Conventional techniques for the detection of certain bacteria, such as Escherichia coli, are very lengthy, require trained operators and can be subjective, since they are based on the capacity of colour discernment of the person performing the analysis. In this work, we describe a portable electronic monitoring system based on colorimetric measurements, which is capable of speeding up the detection of bacteria in comparison with the conventional techniques. Such system enhances the threshold of detection and automates the sampling of the measure. Our system is capable of decreasing the waiting and processing time of more than 60% with respect to conventional methods (48 h). In addition to the mere hardware system, we propose three different simple algorithms to recognise that bacteria are present in the sample. Furthermore, we show that there is a correlation with the number of microorganisms. Given the portability of the system, and the easy scalability, this solution paves the way to a fast and in situ determination of water quality based on a cost-effective electronic system.