Electrochemical capacitive dengue aptasensor using NS1 in undiluted human serum

Area of Science:

• Biomedical Engineering
• Biosensor Technology
• Electrochemical Methods

Background:

• Non-structural 1 (NS1) protein is an early biomarker for dengue, Zika, and Chikungunya infections.
• Accurate quantification of NS1 is crucial for timely diagnosis and disease management.
• Existing diagnostic methods may lack the sensitivity or speed required for early detection.

Purpose of the Study:

• To develop a highly sensitive electrochemical aptasensor for selective NS1 protein quantification.
• To utilize DNA aptamers co-immobilized with a redox probe on gold electrodes.
• To establish a label-free detection platform for point-of-care applications.

Main Methods:

• Fabrication of a gold electrode aptasensor co-immobilized with DNA aptamers and 6-(ferrocenyl)hexanethiol (FCH).
• Utilization of electrochemical capacitive spectroscopy to convert impedance to capacitance information.
• Optimization of aptamer-to-FCH ratio and blocking with bovine serum albumin for enhanced specificity.

Main Results:

• The aptasensor demonstrated high sensitivity (3-4 nF/decade) and a low limit of detection (30.9-41.8 fg/mL).
• A wide linear detection range (10 pg/mL to 1 µg/mL or 100 ng/mL) was achieved with minimal error (<1% RSD).
• Successful detection of NS1 in both phosphate-buffered saline and undiluted human serum samples.

Conclusions:

• The developed aptasensor is capable of detecting NS1 protein within the clinical range.
• This platform offers high sensitivity and specificity for early detection of dengue and related viral infections.
• The technology holds promise for label-free, miniaturized point-of-care diagnostic devices.