Fig. 9. (a–c) Fluorescence images at 2 mg ml⁻¹ concentration under bright field, and blue and green excitation filters. (d–f) Fluorescence images at 4 mg ml⁻¹ concentration under bright field, and blue and green excitation filters. (g–i) Control images of bacteria under bright field, and blue and green excitation filters obtained using a fluorescence microscope.