Abstract
Organically modified silica (ORMOSILS) thin films produced by sol-gel method were imprinted with two bacterial strains as whole cells in order to develop an easy, fast and specific probe to detect and specifically identify these micro-organisms when present in water samples. An important feature of the imprinting process was the molecular finger-prints left by these microorganisms alongside morphology, into imprinted film cavities. The films also showed high selectivity toward the imprinted template and were able to discriminate between two very close bacterial species (E. coli and S. typhimurium). In addition, several central physical parameters of the experimental water solution were examined (i.e., pH, ionic strength and the organic load exemplified by NaCl and TOC concentration, respectively). The method sensitivity to different bacterial concentrations was studied by confocal microscopy (CLSM) and quartz crystal microbalance (QCM) tools. Results showed that increased bacterial concentrations favor rapid adsorption onto imprinted sol-gel films with high affinity, while low pH, increased organic load and high ionic concentrations (i.e., seawater) interfere with bacteria re-adsorption, reducing detection capability. Under average drinking water chemical composition the method proved to be highly efficient.
Highlights
The source of 80% of gastrointestinal illnesses in developing countries is caused by consumption of polluted drinking water
In an earlier study it was shown that imprinted sol-gel films differentiate between types of microorganisms based on shape and size variation and only cavities-specific adsorption takes place (Figures 1(A) and (B)) [7]
In the present study different techniques were applied in order to find out the impact of different physical parameters on the adsorption of test bacteria on the imprinted sol-gel films
Summary
The source of 80% of gastrointestinal illnesses in developing countries is caused by consumption of polluted drinking water. The technique is applicable to all kinds of samples, it is most advantageous in turbid and marine waters were direct filtration may be hindered Variations of this method have been developed for all faecal indicator bacteria in question: E. coli, coliforms, enterococci, bacteriophages and C. perfringens [3,4,5]. The main drawback of this method is that MPN procedure demands long incubation time and large incubator space due to the numerous experimental tubes required. Another highly used method is membrane filtration (MF), an alternative method for identification and quantification of bacteria present in water samples [2]. The MF method in spite of its global acceptance in water microbiology laboratories still has several drawbacks: relatively long incubation times, occasionally false positive results and requirement for relatively clear water samples
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
