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

Area of Science:

• Analytical Chemistry
• Biochemistry
• Plant Science

Background:

• Copper ions (Cu²⁺) are essential micronutrients for plants, but their excess can be toxic.
• Understanding Cu²⁺ uptake, transport, and storage mechanisms in plants is crucial for agriculture and environmental science.
• Developing sensitive and selective methods for detecting Cu²⁺ in biological systems is an ongoing challenge.

Purpose of the Study:

• To design and synthesize a novel Rhodamine B-based fluorescent probe (RBO) for selective and sensitive detection of Cu²⁺.
• To investigate the probe's performance under physiological conditions and determine its detection limit.
• To visualize and analyze the distribution of Cu²⁺ in plant tissues using laser scanning confocal microscopy.

Main Methods:

• Synthesis of a Rhodamine B-based fluorescent probe (RBO).
• Spectroscopic analysis (fluorescence and color change) to detect Cu²⁺.
• Laser scanning confocal microscopy to visualize Cu²⁺ distribution in maize roots.

Main Results:

• The synthesized RBO probe exhibits high selectivity and sensitivity towards Cu²⁺ over other metal ions.
• Under physiological conditions (pH 7.0), RBO shows a rapid fluorescence increase and color change upon addition of Cu²⁺.
• The detection limit for Cu²⁺ was determined to be as low as 28 nM.
• Confocal microscopy revealed that Cu²⁺ primarily accumulates in the vascular cylinder of maize roots, with minimal presence in epidermal cells.

Conclusions:

• The RBO probe is a valuable tool for sensitive and selective detection of Cu²⁺ in biological samples.
• The findings provide insights into the distribution patterns of Cu²⁺ in maize roots, aiding the understanding of plant metal homeostasis.
• This research contributes to understanding plant uptake, transport, and storage mechanisms of essential micronutrients like copper.