Colorimetric detection of polycyclic aromatic hydrocarbons by using gold nanoparticles

Area of Science:

• Environmental Chemistry
• Nanomaterials Science
• Analytical Chemistry

Background:

• Polycyclic Aromatic Hydrocarbons (PAHs) are environmental contaminants found in various sources.
• Effective detection methods for PAHs are crucial for environmental remediation and monitoring.
• Gold nanoparticles (AuNPs) offer unique optical properties suitable for sensing applications.

Purpose of the Study:

• To develop a novel colorimetric detection method for specific PAHs, phenanthrene (Phe) and pyrene (Pyr).
• To utilize gold nanoparticles (AuNPs) as a basis for this new sensing technique.
• To optimize assay parameters for enhanced detection performance.

Main Methods:

• Synthesis of gold nanoparticles (AuNPs) using trisodium citrate as a reducing agent.
• Development of a colorimetric assay incorporating ammonium nitrate (NH4NO3) as a reactant.
• Optimization of key assay parameters including NH4NO3 concentration and volume, MES buffer conditions, and reaction time.
• Validation of the method's selectivity and anti-interference capabilities.

Main Results:

• Achieved limits of detection of 0.06 mg/L for phenanthrene (Phe) and 0.087 mg/L for pyrene (Pyr).
• Demonstrated good selectivity and anti-interference ability for the target PAHs.
• Successfully applied the colorimetric method to detect PAHs in real water samples (tap and mineral water) with satisfactory outcomes.

Conclusions:

• The developed gold nanoparticle-based colorimetric method provides an effective and sensitive means for detecting phenanthrene and pyrene.
• The method exhibits favorable selectivity and anti-interference properties, making it suitable for environmental water analysis.
• This novel approach offers a promising tool for the routine monitoring of PAHs in aquatic environments.