An interference-free SERS-based aptasensor for chlorpyrifos detection.

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Environmental Science

Background:

• Pesticide residues, like chlorpyrifos (CPF), pose risks to environmental and human health.
• Accurate and sensitive detection methods are crucial for monitoring pesticide contamination.
• Existing methods may suffer from matrix effects in real-world samples.

Purpose of the Study:

• To develop an interference-free aptasensor for the trace detection of chlorpyrifos (CPF).
• To enhance the anti-matrix effect ability for reliable detection in complex samples.
• To validate the aptasensor's performance against established analytical techniques.

Main Methods:

• Fabrication of a Surface-Enhanced Raman Spectroscopy (SERS)-based aptasensor using gold nanoparticles coated with Prussian blue (Au@PB NPs).
• Utilizing a unique Raman emission at 2160 cm⁻¹ to avoid spectral overlap with sample matrices.
• Optimizing sensor conditions for linear response and low detection limits.

Main Results:

• The aptasensor demonstrated a linear detection range of 0.1-316 ng mL⁻¹ for CPF.
• Achieved a low limit of detection (LOD) of 0.066 ng mL⁻¹.
• Successfully applied to detect CPF in real samples (cucumber, pear, river water) with results correlating well with HPLC-MS/MS.

Conclusions:

• The developed aptasensor offers interference-free, specific, and sensitive detection of CPF.
• The Au@PB NPs SERS tags effectively mitigate matrix effects.
• This strategy provides a robust platform for pesticide residue analysis and environmental monitoring.