Label-free hairpin-like aptamer and EIS-based practical, biostable sensor for acetamiprid detection

Area of Science:

• Analytical Chemistry
• Biotechnology
• Environmental Science

Background:

• Acetamiprid (ACE) is a broad-spectrum pesticide posing potential human health risks.
• Aptamers (Ap-DNA) offer potential as sensitive analytical tools for pesticide detection.
• Developing rapid and reliable methods for ACE detection is crucial for environmental and food safety.

Purpose of the Study:

• To develop a label-free electrochemical sensing assay for acetamiprid (ACE) determination.
• To investigate the specific binding interaction between ACE and aptamer-DNA (Ap-DNA).
• To evaluate the performance of the developed Ap-DNA biosensor for ACE detection in real samples.

Main Methods:

• Electrochemical impedance spectroscopy (EIS) was employed for label-free ACE detection.
• Circular dichroism (CD) spectroscopy was used to study the structural changes of Ap-DNA.
• The Ap-DNA sensor was tested for selectivity against other pesticides and in environmental water and orange juice samples.

Main Results:

• Ap-DNA formed a stable hairpin-like structure, creating specific binding sites for ACE.
• The binding of ACE to Ap-DNA induced an increase in charge transfer resistance (RCT), proportional to ACE concentration.
• The biosensor demonstrated high sensitivity (detection limit of 1 nM) and selectivity for ACE.
• Spiked recoveries in lake water (85.8–93.4%) and orange juice (83.7–89.4%) confirmed its applicability.

Conclusions:

• A novel impedimetric Ap-DNA biosensor was successfully developed for sensitive and selective ACE detection.
• The sensor exhibits excellent performance in analyzing real-world samples, indicating practical application potential.
• This aptamer-based sensor offers a promising tool for on-site monitoring of acetamiprid.