Prototype amperometric biosensor for sialic acid determination

Area of Science:

• Electrochemistry
• Biosensor Technology
• Biochemistry

Background:

• Sialic acid (SA) is a crucial biomarker in various biological processes and diseases.
• Accurate and sensitive detection of SA is vital for clinical diagnostics and pharmaceutical research.
• Existing methods for SA detection can be complex and time-consuming.

Purpose of the Study:

• To develop and characterize a novel amperometric biosensor for the detection of free sialic acid (SA).
• To evaluate the performance and applicability of the SA biosensor in biological and pharmaceutical samples.
• To expand the biosensor's capability to detect bound sialic acid.

Main Methods:

• Co-immobilization of N-acetylneuraminic acid aldolase and pyruvate oxidase enzymes on a platinum disk electrode.
• Detection of hydrogen peroxide produced by enzymatic reactions via anodic amperometry.
• Electropolymeric coating of the electrode surface to enhance selectivity.
• Optimization of enzyme layer composition and operating conditions (pH 7.2, 37°C).

Main Results:

• The SA biosensor exhibited a limit of detection of 10 µM with linearity up to 3.5 mM (r = 0.9987).
• The biosensor maintained 85% sensitivity after 8 days with excellent reproducibility (CV = 2.3%).
• The inclusion of sialidase enabled the detection of bound sialic acid, broadening its application scope.

Conclusions:

• The developed amperometric biosensor is a sensitive, selective, and reproducible tool for free and bound sialic acid determination.
• The biosensor shows promise for bioanalytical applications, including tumor marker screening and therapy monitoring.
• This biosensor offers a valuable alternative for SA analysis in biological and pharmaceutical contexts.