Application of screen-printed electrodes as transducers in affinity flow-through sensor systems

Area of Science:

• Electrochemistry
• Biosensors
• Analytical Chemistry

Background:

• Low molecular weight compounds require sensitive detection methods.
• Affinity assays offer high specificity for analyte recognition.
• Flow-through systems enable automated and continuous analysis.

Purpose of the Study:

• To develop and optimize an affinity flow-through sensor system.
• To demonstrate the system's capability for determining biotin and atrazine.
• To establish a sensitive and reproducible analytical method.

Main Methods:

• Heterogeneous competitive affinity assay using immobilized binding proteins (streptavidin or antibody).
• Enzyme labeling (peroxidase) and electrochemical detection of reaction products.
• Amperometric measurement at -600 mV vs a screen-printed platinum electrode.
• Automated reagent delivery in an unsegmented flow-through system.

Main Results:

• Optimized biotin determination with a linear range of 0.045–2 µg/L and RSD < 3.8%.
• Developed atrazine assay with a linear range of 0.01–10 µg/L, IC50 = 0.4 µg/L, and RSD < 4.6%.
• Successful application to atrazine-spiked water samples.
• Sensor surface regeneration achieved by streptavidin removal.

Conclusions:

• The developed affinity flow-through sensor system is effective for sensitive determination of low molecular weight compounds.
• The system demonstrates high reproducibility and applicability to real-world samples.
• The sensor offers a promising platform for automated and efficient analytical applications.