Lanthanide doped carbon dots as a fluorescence chromaticity-based pH probe

Area of Science:

• Nanotechnology
• Materials Science
• Analytical Chemistry

Background:

• Accurate pH monitoring is crucial in biological and chemical systems.
• Existing pH probes often lack precision or have limited applicability.
• Carbon dots (C-dots) offer unique optical properties for sensing applications.

Purpose of the Study:

• To design and synthesize a novel colorimetric and fluorescent pH probe.
• To investigate the pH-sensing capabilities of doped C-dots.
• To evaluate the probe's accuracy and applicability in biological imaging.

Main Methods:

• Doping carbon dots (C-dots) with Eu(III), Tb(III), and 2,6-pyridinedicarboxylic acid (DPA).
• Characterizing the optical properties (excitation/emission wavelengths) of the resulting nanoparticles.
• Utilizing Commission Internationale de L'Eclairage (CIE) chromaticity diagrams for linear pH determination.
• Applying the nanoprobe for pH visualization in MCF-7 cells.

Main Results:

• The developed nanoparticles function as effective fluorescent indicators for pH.
• pH variations induce optical effects through altered energy transfer.
• A linear relationship between fluorescence and pH (3.0-10.0) was established using CIE chromaticity.
• The nanoprobe demonstrated high accuracy, surpassing previous pH indicator probes.
• Successful visualization of intracellular pH in human breast adenocarcinoma cells (MCF-7).

Conclusions:

• A novel, highly accurate pH nanoprobe based on doped C-dots was successfully developed.
• The probe exhibits a continuous color variation and linear pH response, suitable for quantitative analysis.
• The use of chromaticity coordinates enhances pH measurement accuracy.
• The nanoprobe is a promising tool for real-time pH monitoring in biological systems.