Single-Particle Collision Electrochemical Biosensor Developed by a Typical Alkaline Phosphatase-Catalyzed Silver...

Area of Science:

• Electrochemistry
• Nanotechnology
• Biomedical Engineering

Background:

• Alkaline phosphatase (ALP) is a crucial biomarker for disease monitoring and a common biolabel in bioanalysis.
• Existing ALP assay methods require further development for enhanced sensitivity and simplified procedures.

Purpose of the Study:

• To develop a novel single-particle collision-based electrochemical biosensor for alkaline phosphatase (ALP) detection.
• To establish a homogeneous assay platform that eliminates the need for electrode modification and washing steps.

Main Methods:

• Utilized an ALP-catalyzed silver deposition reaction on gold nanoparticles (Au NPs).
• Generated Au@Ag NPs were detected via stochastic collisions with a microelectrode, producing transient current spikes.
• Quantified ALP activity based on collision frequency and charge, indicating the amount of Au@Ag NPs produced.

Main Results:

• Achieved a sensitive detection limit of 2 mU/mL for ALP activity.
• Demonstrated background-free operation, ensuring absolute selectivity.
• Successfully applied the assay for ALP detection in serum samples and inhibitor screening.
• Adapted the strategy for a new enzyme-linked immunosorbent assay (ELISA) to detect human immunoglobulin G (IgG) at 5 ng/mL.

Conclusions:

• The developed single-particle collision-based electrochemical biosensor offers a sensitive, selective, and homogeneous platform for ALP activity detection.
• This approach eliminates complex pre-treatment steps, simplifying bioanalytical procedures.
• The strategy holds promise for developing advanced biosensors for disease diagnosis and various bioanalytical applications.