Electrical characterization of phytoplankton suspensions using impedance spectroscopy

This study used impedance spectroscopy measurements to extract the electrical properties of phytoplankton cells in suspension. Experimental measurements were acquired, and the single-shell model was applied to extract the specific membrane capacitance, cytoplasm permittivity, and conductivity of assumingly spherical cells in suspension utilizing Maxwell's mixture theory of a controlled volume fraction of cells. The impedance of suspensions of algae was measured at different frequencies ranging from 3 kHz to 10 MHz and impedance values were compared to investigate differences between two types of cells by characterizing their change in cytoplasm permittivity and specific membrane capacitance. Differentiation between healthy control and nitrogen-depleted cultured algae was attempted. The extracted specific membrane capacitances of Chlamydomonas and Selenastrum were 15.5 +/- 3.6 and 40.6 +/- 12.6 mF m(- 2) respectively. Successful differentiation based on the specific membrane capacitance of different algae species was achieved. However, no significant difference was noticed between nitrogen-abundant and nitrogen-depleted cultures.

Automated summary

This study used impedance spectroscopy measurements to extract the electrical properties of phytoplankton cells in suspension and successfully differentiated different algae species based on their specific membrane capacitance. There was no significant difference in the electrical properties between nitrogen-depleted and healthy control cultures of algae.