Highly sensitive laser-induced fluorescence detector for algal identification by capillary electrophoresis

• A LIF-CE method for analyzing algae is described. • Algae are identified through electrophoretic patterns. • High-sensitivity LIF enables single-cell detection. • Superior miniaturization and integration versus traditional LIF systems. To achieve rapid and efficient detection of algal cells, this study developed a high-sensitivity laser-induced fluorescence detector with dimensions of 14 × 5.7 × 2.8 cm 3 . Microalgae were analyzed using a combination of laser-induced fluorescence and capillary electrophoresis. During capillary electrophoresis separation, differences in the composition and content of cellular components among various algal species resulted in characteristic peak shapes and heights in the electrophoresis patterns. Experimental results demonstrated that this method obtained characteristic electrophoresis profiles for different algae and enabled effective differentiation of microalgal species based on their peak shapes. The detector exhibits a chlorophyll a detection limit as low as 40 pM. This exceptional sensitivity enables single-cell analysis, allowing detection even when cellular contents are diluted by factors over 3.5 × 10 3 . This study developed a miniaturized and highly sensitive laser-induced fluorescence detector, based on which the analytical method established provides a powerful new tool for the rapid identification and single-cell analysis of algae.