A sensitive, label-free, aptamer-based biosensor using a gold nanoparticle-initiated chemiluminescence system

Area of Science:

• Nanotechnology
• Biochemistry
• Analytical Chemistry

Background:

• Label-free biosensors are crucial for efficient biomolecule detection.
• Gold nanoparticles (AuNPs) offer unique catalytic and optical properties.
• Aptamers provide high specificity for target recognition.

Purpose of the Study:

• To develop a novel aptamer-based chemiluminescent biosensor for thrombin detection.
• To utilize the catalytic activity of gold nanoparticles (AuNPs) in a label-free assay.
• To enhance sensitivity and reduce assay complexity.

Main Methods:

• Employed unmodified gold nanoparticles (AuNPs) and aptamers for thrombin detection.
• Leveraged the luminol-hydrogen peroxide chemiluminescence (CL) reaction.
• Utilized AuNP aggregation induced by aptamer-target binding in the presence of NaCl to enhance CL signal.

Main Results:

• The biosensor demonstrated label-free detection of thrombin.
• Unmodified AuNPs effectively differentiated between folded and unstructured aptamers.
• Achieved a low detection limit of 26 fM for thrombin.
• Exhibited sensitivity over 4 orders of magnitude greater than colorimetric methods.

Conclusions:

• A simple, rapid, and highly sensitive aptamer-based chemiluminescent biosensor was successfully developed.
• The assay requires no covalent functionalization, simplifying the process.
• This method presents a cost-effective and efficient approach for thrombin detection.