A plastic total internal reflection photoluminescence device for enzymatic biosensing

Area of Science:

• Biosensor technology
• Photoluminescence spectroscopy
• Biomedical engineering

Background:

• Total internal reflection fluorescence (TIRF) microscopy is a powerful technique for sensitive detection.
• Existing TIRF methods often require excitation filters, increasing complexity and cost.
• Photoluminescence offers an alternative detection mechanism that can encompass both fluorescence and phosphorescence.

Purpose of the Study:

• To develop a novel total internal reflection photoluminescence (TIRPh) biosensor platform.
• To demonstrate the utility of TIRPh for enzymatic sensing without excitation filters.
• To create a cost-effective and portable biosensor for hydrogen peroxide (H2O2) detection.

Main Methods:

• Fabrication of a PMMA/PDMS waveguide system for TIRPh.
• Immobilization of a ruthenium-based phosphorescent dye (Ru(dpp)3) on the waveguide core.
• Integration of catalase for enzymatic detection of H2O2, utilizing Ru(dpp)3 phosphorescence as a transducer.
• Characterization of sensor performance, including detection limit and linear range.

Main Results:

• The TIRPh device achieved a detection limit of (2.2 ± 0.6) μM for H2O2.
• A high phosphorescence to scattered excitation light ratio of 76 ± 10 was observed without filtering.
• The sensor demonstrated a linear response from 0.1 mM to 20 mM H2O2.
• The platform successfully functioned as an enzymatic biosensor without photolithography or etching.

Conclusions:

• The developed TIRPh device represents the first enzymatic biosensor platform based on total internal reflection photoluminescence.
• This approach offers a cost-effective, filter-free, and portable sensing solution with low excitation interference.
• The technology shows significant promise for field-portable and on-site H2O2 monitoring.