A Fibre-Optic Coupled Fluorescence Multiwavelength Sensor for Automated Monitoring of Bacteria Culture from Drinking Water

Autonomous online measurement of β-D-glucuronidase activity in surface water: is it suitable for rapid E. coli monitoring?

“…The automated TECTA™ B16 technology (ENDETEC, Canada) is a fibre-optic coupled fluorescence multi-wavelength sensor that shortens the culture time of E. coli through a patented technology involving a fibre-optic probe and a miniature spectrometer (Brown et al, 2013). Measurement cartridges contain proprietary growth media with metabolic substrates for the specific detection of E. coli and total coliforms through their glucuronidase and galactosidase activities, respectively.…”

“…Cartridges are incubated at 35 C into a benchtop instrument and in presence of E. coli, a hydrophobic fluorescent metabolite is released from GLUC-mediated breakdown of the substrate (a glucuronic acid conjugate) and detected by the instrument. The fluorescence is continuously monitored by an optical fibre coupled to the instrument miniature spectrometer and any background turbidity and matrix effects are reduced through absorption of the fluorescent metabolite to a siloxane polymer bead integrated at the bottom of each cartridge (Brown et al, 2013). The software converts the time at which a given fluorescence intensity is detected (time-to-detection, TTD) into a concentration of bacteria (CFU.100 mL À1 ) using a default calibration curve provided by the manufacturer and based on water samples from Lake Ontario.…”

“…In recent years, efforts were made to automate the detection of the fluorescence generated by the enzymatic reaction in combination with a culture step (Angelescu et al, 2018;Briciu-Burghina et al, 2015;Brown et al, 2013;Heery et al, 2016;Tryland et al, 2015) or not (Koschelnik et al, 2015;Ryzinska-Paier et al, 2014). Some of these enzyme-based technologies can be organised in remote and/or low resource settings, either for grab sample testing (Wildeboer et al, 2010;Wu et al, 2018) or for autonomous online monitoring of E. coli at high temporal frequencies (<1 h) (Ender et al, 2017;Stadler et al, 2016).…”

Detection of Hg2+in water environment by fluorescence spectroscopic methods

“…However, the spectrofluorometer for fluorescence spectra measurements used in the laboratory is of high power consumption and large volume, which leads to the impossibility of on-site testing [5]. Fortunately, the fiber spectroscopic techniques can also been used for spectral characteristics [9,10,11]. The measurements of fluorescence spectra could be obtained by means of optical fiber spectroscopic techniques [12,13].…”