Development of a microalgal PAM test method for Cu(II) in waters: comparison of using spectrofluorometry

Area of Science:

• Environmental Science
• Analytical Chemistry
• Biotechnology

Background:

• Accurate monitoring of copper (Cu) concentrations in water supplies is crucial for public health and environmental safety.
• Existing methods for copper detection can be complex or lack the sensitivity required for regulatory compliance.

Purpose of the Study:

• To develop and validate a novel biosensor for detecting copper(II) in water samples.
• To assess the efficacy of immobilized Dictyosphaerium chlorelloides cells for copper monitoring.
• To identify sensitive parameters for copper analysis using Pulse Amplitude Modulation (PAM).

Main Methods:

• Immobilization of Dictyosphaerium chlorelloides (Chlorophyta) cells within a silicate sol-gel matrix.
• Toxic effects of Cu(II) evaluated using fluorescence measurements and Pulse Amplitude Modulation (PAM) parameters.
• Analysis of sensitive indicators like Fm' and qN for copper determination.
• Development of a resistant strain of D. chlorelloides for enhanced selectivity.

Main Results:

• The D. chlorelloides PAM biosensor demonstrated a detection limit of 0.6 mg l(-1) for Cu(II).
• Fm' and qN were identified as the most sensitive parameters for copper analysis in water.
• The biosensor's detection limit is within the range for establishing regulatory compliance for copper levels.
• A copper-resistant strain of D. chlorelloides was successfully produced, improving metal determination selectivity.

Conclusions:

• Immobilized D. chlorelloides cells offer a sensitive and viable platform for developing a copper biosensor.
• PAM fluorometry, specifically Fm' and qN parameters, provides effective indicators for copper monitoring in aquatic environments.
• The developed biosensor can aid in ensuring water quality by detecting copper concentrations exceeding regulatory limits.