Aptamer-based fluorescent sensor for highly sensitive detection of methamphetamine

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Methamphetamine (METH) is a dangerous illicit drug with significant public health implications.
• Accurate and rapid detection of METH in biological samples is crucial for clinical and forensic applications.
• Existing detection methods often face limitations in sensitivity, selectivity, or operational simplicity.

Purpose of the Study:

• To develop a highly sensitive and selective fluorescence aptasensor for the detection of methamphetamine (METH).
• To utilize graphene oxide (GO) as a platform for fluorescence quenching and signal restoration in the aptasensor.
• To validate the aptasensor's performance in real biological samples like saliva and urine.

Main Methods:

• A high-affinity aptamer (APT-40nt) was identified using molecular modeling and labeled with a fluorescein (FAM) dye.
• The FAM-labeled aptamer was immobilized on a graphene oxide (GO) platform, leading to fluorescence quenching via π-stacking.
• Methamphetamine (METH) detection was achieved by observing fluorescence restoration upon METH binding to the aptamer, causing its detachment from GO.

Main Results:

• The fluorescence aptasensor demonstrated a linear detection range for METH from 1–50 and 50–200 nM.
• An ultra-low detection limit of 0.78 nM was achieved under optimized conditions.
• The aptasensor showed minimal interference from other illicit drugs and metabolites, with satisfactory recoveries (87%-111%) in spiked saliva and urine samples.

Conclusions:

• The developed fluorescence aptasensor provides a sensitive, selective, and cost-effective method for METH detection.
• The aptasensor is suitable for on-site detection of METH in biological fluids like saliva and urine.
• This approach offers a promising strategy for rapid screening and monitoring of METH abuse.