Aptamer-based homogeneous protein detection using cucurbit[7]uril functionalized electrode.

Area of Science:

• Analytical Chemistry
• Biosensors
• Nanotechnology

Background:

• Homogeneous protein detection assays often face challenges with sensitivity and specificity.
• Aptasensors offer a promising platform for protein detection, but require efficient signal amplification strategies.
• Host-guest chemistry, particularly using cucurbiturils, presents unique opportunities for molecular recognition and capture.

Purpose of the Study:

• To develop a novel homogeneous protein detection strategy using a cucurbit[7]uril (CB[7]) functionalized electrode.
• To achieve highly sensitive and specific electrochemical detection of target proteins.
• To demonstrate the method's applicability in complex biological samples like serum.

Main Methods:

• Fabrication of an electrode functionalized with cucurbit[7]uril (CB[7]) molecules.
• Utilizing aptamer-target protein binding followed by exonuclease-catalyzed digestion of methylene blue (MB)-labeled DNA.
• Employing the host-guest interaction between CB[7] and MB for signal amplification on the electrode surface.

Main Results:

• The proposed method demonstrated a linear response for osteopontin detection from 50 to 500 ng mL(-1).
• Achieved a low detection limit of 10.7 ng mL(-1) for osteopontin.
• Exhibited high specificity and good reproducibility, and was successfully applied to serum samples.

Conclusions:

• The CB[7] functionalized electrode provides a powerful and sensitive platform for homogeneous protein detection.
• The combination of aptamers, exonuclease digestion, and CB[7] host-guest chemistry enables efficient signal amplification.
• This method offers a robust tool for clinical diagnostics and biomarker quantification in biological fluids.