4.6 Article

LED-Based Photoacoustic NO2 Sensor with a Sub-ppb Detection Limit

Journal

ACS SENSORS
Volume 6, Issue 9, Pages 3303-3307

Publisher

AMER CHEMICAL SOC
DOI: 10.1021/acssensors.1c01073

Keywords

photoacoustic spectroscopy; NO2; trace gas sensor; high sensitivity; light-emitting diode

Funding

  1. Academy of Finland [326444, 314364]
  2. Academy of Finland's Flagship Programme, Photonics Research and Innovation (PREIN) [320167]

Ask authors/readers for more resources

In this study, a high-sensitivity light-emitting diode (LED)-based photoacoustic NO2 sensor was demonstrated, achieving a sub-ppb detection limit and excellent stability through cantilever-enhanced photoacoustic detection and two-channel relative measurement. The results show great potential for the development of cost-effective and sensitive detectors for a variety of other trace gases, as LEDs are available at a wide selection of emission wavelengths.
A high-sensitivity light-emitting diode (LED)-based photoacoustic NO2 sensor is demonstrated. Sensitive photoacoustic gas sensors based on incoherent light sources are typically limited by background noise and drifts due to a strong signal generated by light absorbed at the photoacoustic cell walls. Here, we reach a sub-ppb detection limit and excellent stability using cantilever-enhanced photoacoustic detection and perform a two-channel relative measurement. A white-light LED is used as a light source, and the spectrum is divided into two wavelength channels with a dichroic filter. The photoacoustic signals generated by the two wavelength channels are measured simultaneously and used to solve the NO2 concentration. The background signal is highly correlated between the two channels, and its variations are suppressed in the relative measurement. A noise level below 1 ppb is reached with an averaging time of 70 s. This is, to the best of our knowledge, the first time a sub-ppb detection limit is demonstrated with an LED-based photoacoustic NO2 sensor. As LEDs are available at a wide selection of emission wavelengths, the results show great potential for development of cost-effective and sensitive detectors for a variety of other trace gasses as well.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available