Polyluminol/hydrogel composites as new electrochemiluminescent-active sensing layers.

Area of Science:

• Electrochemistry
• Materials Science
• Biosensor Technology

Background:

• Electrochemical sensors offer sensitive detection methods.
• Hydrogel matrices are versatile for immobilizing biomolecules and templating material synthesis.
• Polyluminol exhibits electrochemiluminescent properties suitable for sensing applications.

Purpose of the Study:

• To develop novel electrochemiluminescent (ECL) sensors and biosensors using polyluminol/hydrogel composite sensing layers.
• To investigate the use of hydrogel matrices, specifically calcium alginate and TMOS-based silica, for electropolymerization of luminol and enzyme immobilization.
• To create reagentless, disposable biosensors for detecting hydrogen peroxide and choline.

Main Methods:

• Electropolymerization of luminol onto screen-printed electrodes (SPEs) coated with hydrogel films.
• Cyclic voltammetry (CV) for electropolymerization.
• Enzyme immobilization via entrapment within the hydrogel matrix for biosensor development (using choline oxidase for choline detection).
• Optimization of polymerization conditions, enzyme loading, and hydrogel pore size.

Main Results:

• Successful fabrication of polyluminol/hydrogel composite sensing layers.
• Development of sensors for H2O2 and biosensors for choline detection.
• Achieved detection limits down to micromolar concentrations for both analytes.
• Demonstrated wide dynamic ranges spanning three orders of magnitude, starting from 4 × 10⁻⁷ M.
• Utilized calcium alginate and TMOS-based silica as effective hydrogel matrices.

Conclusions:

• Polyluminol/hydrogel composites are effective ECL-active sensing layers.
• The developed sensors and biosensors are reagentless, disposable, and easy to use.
• Calcium alginate offers a novel and easily handled hydrogel matrix for such configurations.
• The approach is promising for designing advanced optical sensors and biosensors.