Photonic Crystal Sensors For Volatile Compound Detection

A photonic crystal colorimetric sensor changes visible color to detect and distinguish volatile compounds through dye-photonic crystal combinations and pattern-based responses.
Problem:
Existing Volatile Organic Compound (VOC) sensing methods can be difficult to miniaturize. Some optical methods may not be selective for a specific VOC. Other methods can require heaters and complex fabrication. There is a need for colorimetric devices that detect and distinguish volatile compounds.
Solution:
The technology combines photonic crystals with volatile compound-sensitive dyes to create visible color changes upon exposure. Multiple sections can be arranged to produce a characteristic pattern correlated to compound identity or concentration. The photonic crystal stop band and dye are selected to enhance observable color response. The technology also provides a method that contacts the colorimetric component with a volatile compound.
Technology Overview:
The system includes at least one photonic crystal with a visible-light stopband and at least one dye sensitive to a VOC or Volatile Sulfur Compound (VSC). In array formats, different sections contain different photonic crystal and dye combinations. Exposure to a volatile compound changes dye molecular structure and alters visible color. The resulting pattern can be correlated to the volatile compound or its concentration.
Advantages:

Produces a visible color response to volatile compounds
Supports pattern-based differentiation among compounds or concentrations
Uses photonic crystal and dye selection to enhance color change
Supports array configurations with multiple sensing sections
Can detect both volatile organic compounds and volatile sulfur compounds

Applications:

VOC identification: The technology can distinguish among volatile organic compounds using characteristic color patterns.
Concentration sensing: The technology can correlate a color pattern with volatile compound concentration.
Air quality monitoring: The technology can support monitoring where volatile compounds indicate hazard exposure or air quality conditions.
VSC detection: The technology can detect volatile sulfur compounds through visible color changes.
Chemical screening: The technology can screen acetaldehyde, acetone, and acetic acid using colorimetric sensor arrays.

Stage of Development:

Proof of Concept

A). A schematic illustration of the dye-cPhC colorimetric sensor array. B). Comparison of dye-cPhC and dye paper when exposed to different VOCs. C). Schematic of dye-cPhC’s reflectance spectrum before and after VOC exposure.
Intellectual Property: