An algal cell biosensor for the rapid detection of Cu2+

An algal membrane potential sensor based on extra-cellular technique and electrochemistry was constructed. Membrane potential (MP) and membrane resistance (MR) of algal cell were used for biological indicators of the biosensor. The results showed that MP and MR were significantly correlative with Cu²⁺ concentration. Qualitative detection of Cu²⁺ was realized in the experiment, and the detection limit was 1.0 μmol/l, and response time was of 5-20 min. There was a good linearity relationship between relative MP, relative MR and treatment time of Cu²⁺ solution. Within Cu²⁺ concentration and treatment time of this experiment, the sensor´s membrane electrical information-time effect curve was close to a straight line (R>0.99), which providing a basis of data models for the quantitative determination of Cu²⁺ concentration. The reproducibility and stability of the sensor were also estimated with satisfactory results.