Amino Acid-Functionalized Carbon Quantum Dots for Ultrasensitive and Selective Fluorometric Chlorpyrifos Detection

Area of Science:

• Materials Science
• Nanotechnology
• Environmental Chemistry

Background:

• Carbon quantum dots (CQDs) are semiconductor nanomaterials with unique optical properties and biocompatibility.
• Pesticides, like chlorpyrifos (CP), pose significant environmental and health risks, necessitating sensitive detection methods.
• Amino acids can enhance the functionality of nanomaterials for sensing applications.

Purpose of the Study:

• To synthesize and evaluate amino acid-functionalized CQDs for pesticide detection.
• To compare the performance of CQDs functionalized with different amino acids (L-cysteine, L-tryptophan, L-serine).
• To develop a sensitive and selective fluorescence sensor for chlorpyrifos (CP).

Main Methods:

• Hydrothermal synthesis of CQDs using grape acid and amino acids.
• Characterization using scanning transmission electron microscopy (STEM) and density functional theory (DFT) to analyze surface functionalities and energy levels (HOMO-LUMO).
• Development of a fluorescence sensor for pesticide detection.

Main Results:

• Amino acids successfully enhanced the surface functionalities of CQDs.
• The CQD-based sensor demonstrated high sensitivity and selectivity for CP among tested pesticides.
• Cysteine-doped CQDs exhibited superior sensing performance, detecting CP at concentrations as low as 7.42 × 10^-12 mol L^-1.

Conclusions:

• Amino acid-functionalized CQDs are effective platforms for sensitive and selective pesticide monitoring.
• Cysteine-functionalized CQDs show particular promise for low-concentration CP detection.
• This approach offers a low-cost, environmentally friendly solution for pesticide monitoring in environmental safety and public health.