Development and Automation of a Bacterial Biosensor to the Targeting of the Pollutants Toxic Effects by Portable Raman Spectrometer

Abstract

Water quality monitoring requires a rapid and sensitive method that can detect multiple hazardous pollutants at trace levels. This study aims to develop a new generation of biosensors using a low-cost fiber-optic Raman device. An automatic measurement system was thus conceived, built and successfully tested with toxic substances of three different types: antibiotics, heavy metals and herbicides. Raman spectroscopy provides a multiparametric view of metabolic responses of biological organisms to these toxic agents through their spectral fingerprints. Spectral analysis identified the most susceptible macromolecules in an E. coli model strain, providing a way to determine specific toxic effects in microorganisms. The automation of Raman analysis reduces the number of spectra required per sample and the measurement time: for four samples, time was cut from 3 h to 35 min by using a multi-well sample holder without intervention from an operator. The correct classifications were, respectively, 99%, 82% and 93% for the different concentrations of norfloxacin, while the results were 85%, 93% and 81% for copper and 92%, 90% and 96% for 3,5-dichlorophenol at the three tested concentrations. The work initiated here advances the technology needed to use Raman spectroscopy coupled with bioassays so that together, they can advance field toxicological testing.

Label-Free Surface-Enhanced Raman Scattering-Based Microbial Whole-Cell Biosensor for Acute Toxicity Assessment in Water

“…The dose of copper is an important contribution to the variation in bacterial SERS spectra due to its toxicity. This is consistent with the reported results …”

Recent advances of Raman spectroscopy for the analysis of bacteria

“…Similar to antibiotics, there are studies that investigated bacterial responses to environmental stressors, 97 , 98 heavy metals, and herbicides. 99 These studies are also helpful for the understanding of bacterial inactivation mechanisms and the effect of different stressors or chemicals on bacterial cells. SERS has shown to be a promising method to determine the stress response of bacteria at the molecular level.…”

Electrochemical sensing of Hg(ii) in chicken liver and snail shell extract samples using novel modified SDA/MWCNT electrodes

“…Inductively coupled plasma-mass spectrometry (ICP-MS), 22,23 atomic uorescence spectroscopy (AFS), 24 coulometry, 20 atomic absorption spectroscopy (AAS), 21 and other conventional analytical techniques are widely applied for mercury detection to determine the amount of Hg(II) in food and water samples. These methods generally show good and consistent sensitivity toward Hg(II).…”