A novel CDs@AuNCs-based ratio fluorescence probe for sensitive and visual Fe²⁺ detection

Area of Science:

• * Nanomaterials Science
• * Analytical Chemistry
• * Environmental Science

Background:

• * Iron(II) (Fe²⁺) is crucial for cellular functions, but its dysregulation is linked to various diseases.
• * Accurate detection of Fe²⁺ is vital for clinical diagnostics, pharmaceutical quality control, and environmental monitoring.
• * Existing methods for Fe²⁺ detection often face limitations in sensitivity, selectivity, or complexity.

Purpose of the Study:

• * To develop a ratiometric fluorescence probe for the selective and visual detection of Fe²⁺.
• * To combine the fluorescence properties of carbon dots (CDs) and gold nanoclusters (AuNCs) for enhanced detection.
• * To evaluate the probe's performance in complex real-world samples.

Main Methods:

• * Synthesis of a dual-emission probe by integrating blue-emitting carbon dots (CDs) and red-emitting gold nanoclusters (AuNCs).
• * Optimization of the fluorescence intensity ratio (I₆₁₀/I₄₃₅) for Fe²⁺ quantification.
• * Assessment of the probe's sensitivity, selectivity, photostability, and environmental tolerance.
• * Validation of the probe's accuracy using real samples such as ferrous succinate tablets, environmental water, and juice.

Main Results:

• * The CDs@AuNCs probe exhibited distinct dual fluorescence emissions at 435 nm (CDs) and 610 nm (AuNCs).
• * The optimized I₆₁₀/I₄₃₅ ratio showed excellent sensitivity for Fe²⁺ detection, with a low limit of detection (LOD) of 3.5 nM.
• * The probe demonstrated superior photostability, high tolerance to environmental conditions, and remarkable selectivity for Fe²⁺ over other ions and molecules.
• * Real sample analysis yielded satisfactory recovery rates and low relative standard deviations (RSDs), confirming the method's reliability.

Conclusions:

• * The developed CDs@AuNCs ratiometric fluorescence probe offers a simple, rapid, and cost-effective approach for Fe²⁺ detection.
• * The probe exhibits high sensitivity, selectivity, and stability, making it suitable for complex sample analysis.
• * This technology holds significant promise for practical applications in clinical diagnostics, pharmaceutical quality control, and environmental monitoring.