Hybrid carbon nanotube-gold nanoparticle composite for Nitric Oxide (NO) detection
Sensors
Hybrid carbon nanotube-gold nanoparticle composite for Nitric Oxide (NO) detection (TOP2-323)
Enhancing sensitivity and accuracy in NO monitoring over a wide range of humidity
Overview
Nitric Oxide (NO) detection has a wide application from environmental monitoring, industrial process control, combustion studies, oceanographic study to medical diagnoses. NO is a highly unstable, reactive gaseous molecule, making its detection challenging, especially at low concentrations and in high humidity environments. While some commonly used techniques to monitor NO gas are suitable for in vivo detection in solutions, others are bulky and complex despite being sensitive and accurate for in situ monitoring. NASA Ames Research Center has developed a novel, cutting-edge chemiresistive sensor technology that can selectively detect NO in real time, with a small footprint, handheld design, easy operation, and low power consumption. The innovative composite films, crafted from functionalized single-walled carbon nanotubes (SWCNTs) and gold nanoparticles (AuNPs), redefine the landscape of gas sensing.
The Technology
A hybrid thin film is fabricated by a simple drop-casting method. Functionalized single-walled carbon nanotubes (SWCNTs) and gold nanoparticles (AuNPs) with a diameter of ≈15 nm are drop-casted onto a printed circuit board (PCB) substrate equipped with interdigitated electrodes. The addition of AuNPs to the carbon nanotube networked films enhance sensitivity and lower the detection limit to low parts-per-billion (ppb) concentrations. The gold particle to carbon nanotube ratio is optimized to find the optimum gold nanoparticle loading.
The composite films were tested in both air and nitrogen environments across a wide relative humidity range (0-97%), which is suitable for dissolved Nitric Oxide (NO) detection in sea water for oceanographic study and for human breath analysis in medical diagnosis. The sensors exhibited high selectivity, particularly to NO, outperforming other tested gases. Notably, the sensor reliably detected NO at 10 ppb levels with response times within 10 seconds and recovery time around 1 minute, showcasing excellent reproducibility across sensors and operational efficiency within diverse humidity conditions.
Benefits
- High sensitivity: reliably detecting Nitric Oxide (NO) at concentrations as low as 10 parts-per-billion (ppb)
- Versatility: designed for diverse applications, in various environmental conditions, including high humidity environments, making them suitable for wide range of applications
- Fast and Real-Time monitoring: responds within 10 seconds, recovers within 1 minute, the sensors provide real-time monitoring capabilities, enabling timely detection
- Cost effective: can be easily manufactured using standard materials processing methods, low power consumption, and operates at room temperature
- Reliability and reproducibility: deliver consistent and reliable results across different sensors ensuring reproducibility
- Ease of integration: miniaturization, and designed for easy integration into existing systems and platforms like smart phone and other hand-held devices
Applications
- Environmental monitoring: air quality, pollutants levels and emissions in urban areas, industrial sites, and sensitive ecosystems
- Industrial processes: NO levels in manufacturing processes, combustion systems, and chemical production
- Medical Diagnostics: Nitric oxide being a biomarker for lung and neuro degenerative diseases
- Real time monitoring of NO levels in breath samples for early detection and management of respiratory conditions such as asthma and other lung diseases
- Oceanographic studies: detect NO in seawater, oceanic biochemistry, nutrient cycling, marine ecosystems
- Industrial safety: monitoring hazardous environments
- Automotive emission control: monitor NO emissions from vehicles
Technology Details
Sensors
TOP2-323
ARC-18953-1
https://www.mdpi.com/1424-8220/22/19/7581
