Surface-enhanced Raman Scattering (SERS) microbial sensor for fresh water acute toxicity monitoring

The substances emerging in environmental water bodies are becoming increasingly complex, causing severe ecotoxicological problems. In addition, the intricate interaction among various chemicals in a water body makes it difficult to accurately evaluate the water quality by simply determining the specie and concentration of the chemicals. Thus, acute toxicity evaluation of water body presents significant importance in environmental monitoring, especially in emergency response. This work proposes a SERS approach for evaluating acute toxicity of fresh water for the first time, where indole, an interspecies signal molecule produced by E. coli strains during regulated spore formation, could be affected by toxic substances, was used as indicator. Several key factors that may affect the evaluation of acute toxicity in water were explored, including the concentration of exogenous L-tryptophan and the incubation time of E. coli with L-tryptophan. Finally, the established system was applied to the acute toxicity evaluation of model chemical Cu2+. The IC50 was determined to be 2.028 mg L-1, better than the results reported in the literature. This study demonstrates the feasibility of using SERS-based microbial sensors to assess acute toxicity in water.

Automated summary

The complexity of substances in environmental water bodies is leading to severe ecotoxicological problems. Evaluating water quality accurately based on the species and concentration of chemicals alone is difficult due to the intricate interaction among various chemicals. Therefore, the acute toxicity evaluation of water is of significant importance in environmental monitoring, especially in emergency situations. This study proposes a SERS approach to evaluate the acute toxicity of fresh water for the first time, using indole as an indicator. It demonstrates the feasibility of using SERS-based microbial sensors to assess acute toxicity in water.