This gas sensor features a two‐electrode layout on a solid silicon substrate, with interdigitated gold contacts bridged by a composite layer of reduced or holey graphene oxide (rGO/HGO) topped by exfoliated graphitic carbon nitride (“melon”) nanosheets. Conductivity in this 2D network shifts when target gases interact with oxygen functional groups or with metal and inorganic nanoparticle dopants (Cu, Au, Pd, Pt or various oxides) that tune the layer’s work function. Electromagnetic activation—via UV, visible light or an applied bias—enhances charge transport, while on-chip circuitry continuously monitors conductance changes tied to analyte concentration. An optional humidity control module maintains stable conditions. Materials are prepared by thermal polymerization of dicyandiamide for melon and chemical reduction of graphene oxide with hydrazine, then deposited by dielectrophoresis and drop-casting. Structural and compositional validation is achieved through TEM, SEM, XPS and NMR, and gas‐exposure trials reveal a logarithmic conductance response to oxygen (300–10 000 ppm) and UV-activated CO₂ sensitivity with copper dopants.
Description
What sets this approach apart is its synergy of functionalized 2D carbon materials and customizable nanoparticle doping to precisely adjust work function and selectivity. Controllable hole sizes in HGO enable band-gap tuning for specific analytes, while metal or semiconducting nanoparticles further refine sensitivity and response time. The use of electromagnetic energy to boost charge mobility, combined with integrated humidity regulation, provides stable, room-temperature operation and rapid, reversible sensing. Together, these elements create a highly adaptable platform capable of real-time monitoring across a range of gaseous targets, outperforming conventional metal‐oxide or single‐material sensors in both versatility and accuracy.
Applications
- Industrial gas leak detection
- Indoor air quality monitoring
- Medical breath analysis device
- Greenhouse gas emission monitoring
- HVAC CO2 level control
Advantages
- High sensitivity and wide dynamic range detection of oxygen (300–10 000 ppm) and UV-activated CO₂ sensing
- Enhanced selectivity via tunable work function using metal or inorganic nanoparticle dopants
- Room-temperature, low-power operation with real-time, continuous conductance measurements
- Improved signal strength through electromagnetic activation (UV/visible light or electrical bias)
- Tunable bandgap and adsorption properties by controlling holey graphene oxide and melon nanosheet structure
- Integrated humidity control for stable, reproducible sensor performance
- Compact, chip-scale design compatible with standard silicon fabrication techniques
- Fast response and recovery times enabled by 2D carbon network and nanoparticle functionalizationThe PCAC app is publicly available and can provide real-time calculations and predictions on health outcomes, ensuring accuracy and efficiency in patient assessment. Furthermore, it facilitates data-driven decision-making, and electronic patient record keeping, allowing for comprehensive comparisons among different healthcare facilities.
IP Status
https://patents.google.com/patent/US10801982B2
