Dual-Mode FL-SERS Biosensor for Self-Validating H₂S Detection in Complex Matrices and Mitochondria-Targeted Cellular...

Area of Science:

• * Analytical Chemistry
• * Biomedical Engineering
• * Materials Science

Background:

• * Hydrogen sulfide (H2S) has critical physiological roles and impacts food quality.
• * Accurate detection of H2S requires sensitive, specific, and self-validating methods.
• * Existing detection tools often lack comprehensive validation capabilities.

Purpose of the Study:

• * To develop a dual-mode biosensor for ultrasensitive H2S detection and imaging.
• * To create a self-validating sensing platform for H2S analysis.
• * To enable targeted imaging of H2S within cellular mitochondria.

Main Methods:

• * Fabrication of an azide-functionalized metal-organic framework (UiO-66-N3) coupled with gold nanoparticles (AuNPs).
• * Integration of fluorescence (FL) and surface-enhanced Raman scattering (SERS) detection modes.
• * Functionalization with a MUC1 aptamer and mitochondrial localization sequence for targeted delivery.

Main Results:

• * The biosensor exhibited a dual-response mechanism (FL turn-on, SERS attenuation) upon H2S exposure.
• * Achieved ultrasensitive H2S detection with a wide dynamic range (0.01-500 nM) and pM-level detection limits.
• * Demonstrated successful tumor-specific mitochondrial targeting and imaging of endogenous H2S in living cells.
• * Validated applicability in complex samples like beer and wine, and real-time tracking in cells.

Conclusions:

• * The developed dual-mode biosensor provides a versatile and self-validating platform for H2S detection.
• * This approach offers high sensitivity and specificity for H2S analysis.
• * The biosensor shows significant potential for food safety monitoring and biomedical diagnostics.