Capacitive Saccharide Sensor Based on Immobilized Phenylboronic Acid with Diol Specificity

Area of Science:

• Electrochemistry
• Biosensing
• Analytical Chemistry

Background:

• Saccharide and glycoprotein detection are crucial in diagnostics and research.
• Existing methods can be complex, time-consuming, or require labels.
• Development of sensitive, label-free detection systems is highly desirable.

Purpose of the Study:

• To develop and characterize a capacitive sensor for the sensitive detection of saccharides and glycoproteins.
• To demonstrate the sensor's capability using model analytes such as glucose, fructose, dextran, and human immunoglobulin G (IgG).
• To evaluate the sensor's performance in terms of detection limits and concentration ranges.

Main Methods:

• Fabrication of a capacitive sensor with aminophenylboronic acid (APBA) immobilized on a gold electrode.
• Detection principle based on the selective interaction between diols (in saccharides/glycoproteins) and APBA.
• Testing with various saccharides (glucose, fructose, dextran) and glycoproteins (IgG, horseradish peroxidase) over wide concentration ranges.
• Comparison of sensor performance with existing methods where applicable.

Main Results:

• The sensor achieved low limits of detection (LODs): 0.8 nM for glucose, 0.6 nM for fructose, and 13 pM for dextran.
• Glycoprotein detection was demonstrated, with a LOD of 16 fM for human immunoglobulin G (IgG) over a concentration range of 1.0 x 10^-13 M - 1.0 x 10^-7 M.
• The sensor showed high sensitivity and broad applicability for both saccharides and glycoproteins.

Conclusions:

• The developed capacitive sensor offers a label-free, fast, and sensitive method for detecting saccharides and glycoproteins.
• The sensor demonstrates excellent performance with low LODs, making it suitable for various analytical applications.
• This technology holds promise for advancements in diagnostics and biochemical analysis.