Detection of saxitoxin by a SERS aptamer sensor based on enzyme cycle amplification technology

Area of Science:

• Analytical Chemistry
• Biotechnology
• Environmental Science

Background:

• Saxitoxin (STX) is a potent neurotoxin and a major component of paralytic shellfish poisoning (PSP), posing significant risks to human health.
• Accurate and sensitive detection methods for STX are crucial for public health and environmental monitoring.

Purpose of the Study:

• To develop a simple, sensitive, and quantitative Surface-Enhanced Raman Spectroscopy (SERS) aptasensor for the detection of saxitoxin (STX).
• To establish a reliable method for the micro-detection of biological toxins by modifying aptamer sequences.

Main Methods:

• Development of a SERS aptasensor (AuNP@4-NTP@SiO2) utilizing hairpin aptamers on magnetic beads for STX recognition.
• Employing a rolling circle amplification (RCA) reaction triggered by STX, DNA ligase, and a rolling circle template (T1) to generate long DNA sequences.
• Hybridization of RCA products with SERS probes for rapid and sensitive STX detection.

Main Results:

• The developed SERS aptasensor demonstrated excellent sensing performance for STX detection.
• Achieved a wide linear detection range from 2.0 × 10⁻¹⁰ mol L⁻¹ to 5.0 × 10⁻⁴ mol L⁻¹.
• Established a low limit of detection of 1.2 × 10⁻¹¹ mol L⁻¹ for STX.

Conclusions:

• The AuNP@4-NTP@SiO2 SERS aptasensor provides a highly sensitive and quantitative method for STX determination.
• This approach offers a versatile strategy for the micro-detection of various biological toxins by simply altering the aptamer sequence.
• The developed sensor holds promise for effective monitoring of STX contamination and safeguarding public health.