Plasmonic sensor for hydrogen sulphide in saliva: Multisensor platform and bag format

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Biomedical Engineering

Background:

• Optical sensors are increasingly important for in situ analysis.
• Plasmonic sensors, particularly those using silver nanoparticles (AgNPs), are gaining significant attention.
• Hydrogen sulfide is a key biomarker for various oral diseases.

Purpose of the Study:

• To develop and evaluate a plasmonic sensor for detecting hydrogen sulfide (H2S) in oral environments.
• To compare the performance of the sensor in different assay formats (bag and well microplates).
• To assess the sensor's utility for non-invasive oral disease monitoring.

Main Methods:

• A plasmonic sensor was fabricated using AgNPs immobilized on a Nylon surface.
• The sensor's colorimetric response to H2S was investigated.
• Assay performance was evaluated in bag and well microplate formats.
• RGB image analysis was employed to quantify the color change.
• The sensor was applied to analyze sulfide levels in human saliva samples.

Main Results:

• The sensor exhibited a distinct color change from yellow to brown, correlating with H2S concentration.
• Both assay formats demonstrated good figures of merit.
• The sensor successfully quantified sulfide concentrations in real saliva samples, ranging from 30 to 600 μM/L.
• RGB coordinates provided a reliable analytical signal.
• The sensor demonstrated good selectivity, sensitivity, and rapidity.

Conclusions:

• The developed AgNP-based plasmonic sensor is effective for H2S detection.
• The sensor offers a rapid, non-invasive, and selective method for indirect oral disease assessment.
• The use of RGB coordinates enhances the analytical signal processing.
• This technology holds promise for point-of-care diagnostics in oral healthcare.