Online Monitoring of Water Toxicity by Use of Bioluminescent Reporter Bacterial Biochips

TLDR

The study presents a flow‑through biosensor designed for online, continuous monitoring of water toxicity. The biosensor comprises disposable modular biochips with agar‑immobilized bioluminescent recombinant reporter bacteria, monitored by single‑photon avalanche diode detectors, and was tested over 10 days with inducible and constitutive reporter strains under continuous flow and pulsed exposure to model pollutants and industrial wastewater. The reporter panel detected all simulated contamination events within 0.5–2.5 h, with responses reflecting the contaminant type, indicating that the device could serve as an early warning component in future water safety networks.

Abstract

We describe a flow-through biosensor for online continuous water toxicity monitoring. At the heart of the device are disposable modular biochips incorporating agar-immobilized bioluminescent recombinant reporter bacteria, the responses of which are probed by single-photon avalanche diode detectors. To demonstrate the biosensor capabilities, we equipped it with biochips harboring both inducible and constitutive reporter strains and exposed it to a continuous water flow for up to 10 days. During these periods we challenged the biosensor with 2-h pulses of water spiked with model compounds representing different classes of potential water pollutants, as well as with a sample of industrial wastewater. The biosensor reporter panel detected all simulated contamination events within 0.5-2.5 h, and its response was indicative of the nature of the contaminating chemicals. We believe that a biosensor of the proposed design can be integrated into future water safety and security networks, as part of an early warning system against accidental or intentional water pollution by toxic chemicals.