Enhanced response of a proteinase K-based conductometric biosensor using nanoparticles

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Enzyme Biosensors

Background:

• Proteinases play crucial roles in physiological processes, including protein metabolism.
• Developing sensitive and reproducible biosensors is essential for protein analysis.
• Nanomaterials offer unique properties for enhancing biosensor performance.

Purpose of the Study:

• To develop a conductometric enzyme biosensor for proteinase K.
• To investigate the effect of gold and magnetic nanoparticles on biosensor sensitivity and performance.
• To characterize the biosensor's performance for determining bovine serum albumin (BSA).

Main Methods:

• Immobilization of proteinase K onto gold and magnetic nanoparticles.
• Adsorption of enzyme-nanoparticle conjugates onto a planar interdigitated electrode (IDE).
• Cross-linking of the enzyme-nanoparticle layer on the electrode surface.
• Conductometric characterization using BSA as a standard protein.

Main Results:

• The developed biosensor demonstrated significantly higher sensitivity with nanoparticles compared to the bare electrode.
• Gold nanoparticles yielded superior sensitivity, achieving a maximum response of 154 µs.
• The linear range for BSA determination was 0.5–10 mg/L, with a limit of detection (LOD) of 0.3 mg/L.
• High inter-sensor reproducibility of 3.5% was achieved.

Conclusions:

• Nanoparticle-enhanced proteinase K biosensors offer improved sensitivity for protein analysis.
• Gold nanoparticles are particularly effective in enhancing the performance of conductometric enzyme biosensors.
• The developed biosensor shows promise for practical applications in protein quantification.