A Rhodamine B-based fluorescent probe for imaging Cu2+ in maize roots

A new Rhodamine B-based fluorescent probe (RBO) is successfully designed and synthesized, which is a higher selective and sensitive chemosensor for Cu 2+ than other ions. Under physiological conditions (pH = 7.0), the non emission RBO displays a rapid fluorescence increase together with a color change after addition of Cu 2+ and the detection limit is down to 28   nM, which can clearly illustrate the distribution of Cu 2+ with the help of laser scanning confocal microscope in plant tissues. Eventually, it confirmed that the Cu 2+ accumulates mostly in the vascular cylinder and very less in the epidermal cells of maize roots, which is important to understand how the plants take up, transport and store in the Cu 2+ .