New biosensor for detection of copper ions in water based on immobilized genetically modified yeast cells

• We present newly designed biosensor for detecting copper concentration in water.
• The biosensor is based on immobilized yeast and turns red in the presence of copper.
• The biosensor allows quantification of Cu2+ concentration in many parallel samples.
• Cu2+ level in wastewater can be quantified with no need of specialized equipment.

Contamination of water by heavy metals represents a potential risk for both aquatic and terrestrial organisms, including humans. Heavy metals in water resources can come from various industrial activities, and drinking water can be ex-post contaminated by heavy metals such as Cu2+ from house fittings (e.g., water reservoirs) and pipes. Here, we present a new copper biosensor capable of detecting copper ions at concentrations of 1–100 μM. This biosensor is based on cells of a specifically modified Saccharomyces cerevisiae strain immobilized in alginate beads. Depending on the concentration of copper, the biosensor beads change color from white, when copper is present in concentrations below the detection limit, to pink or red based on the increase in copper concentration. The biosensor was successfully tested in the determination of copper concentrations in real samples of water contaminated with copper ions. In contrast to analytical methods or other biosensors based on fluorescent proteins, the newly designed biosensor does not require specific equipment and allows the quick detection of copper in many parallel samples.