An aptamer folding-based sensory platform decorated with nanoparticles for simple cocaine testing

Area of Science:

• Analytical Chemistry
• Biotechnology
• Materials Science

Background:

• Illicit drug consumption, particularly cocaine, presents significant public health and social challenges.
• Accurate and rapid detection methods are crucial for identifying new psychoactive drugs and monitoring abuse.
• Existing detection techniques may require improvement in sensitivity and specificity for emerging substances.

Purpose of the Study:

• To develop a novel, sensitive, and selective sensory device for detecting cocaine and its primary metabolite, benzoylecgonine (BE).
• To create a combinatorial platform utilizing quantum dots (QDs) and gold nanoparticles (AuNPs) functionalized with aptamers.
• To validate the device's performance in artificial urine samples and assess its adaptability for detecting other drugs of abuse.

Main Methods:

• Fabrication of an aptamer folding-based sensory device (AFSD) by immobilizing QDs and AuNP-aptamer conjugates.
• Utilizing the fluorescence quenching of QDs upon cocaine or BE binding, which induces AuNP-QD proximity.
• Testing selectivity with various interfering substances and validating results with high-performance liquid chromatography (HPLC).

Main Results:

• The AFSD demonstrated selective detection of cocaine and BE, with linearity ranges of 1.0–10 nM and 1.0–25 µM, respectively.
• Achieved low limits of detection: 0.138 nM for cocaine and 1.66 µM for BE.
• The device performed effectively in artificial urine samples and showed good selectivity against common interfering substances.

Conclusions:

• The developed AFSD is a promising tool for cocaine abuse testing, offering high sensitivity and selectivity.
• The platform's modular design, using aptamers, allows for easy adaptation to detect a wide array of addictive drugs.
• This technology holds potential for advancing drug abuse diagnostics and monitoring.