1 research outputs found
Sniffing Entrapped Humans with Sensor Arrays
Earthquakes
are lethal natural disasters frequently burying people
alive under collapsed buildings. Tracking entrapped humans from their
unique volatile chemical signature with hand-held devices would accelerate
urban search and rescue (USaR) efforts. Here, a pilot study is presented
with compact and orthogonal sensor arrays to detect the breath- and
skin-emitted metabolic tracers acetone, ammonia, isoprene, CO<sub>2</sub>, and relative humidity (RH), all together serving as sign
of life. It consists of three nanostructured metal-oxide sensors (Si-doped
WO<sub>3</sub>, Si-doped MoO<sub>3</sub>, and Ti-doped ZnO), each
specifically tailored at the nanoscale for highly sensitive and selective
tracer detection along with commercial CO<sub>2</sub> and humidity
sensors. When tested on humans enclosed in plethysmography chambers
to simulate entrapment, this sensor array rapidly detected sub-ppm
acetone, ammonia, and isoprene concentrations with high accuracies
(19, 21, and 3 ppb, respectively) and precision, unprecedented by
portable sensors but required for USaR. These results were in good
agreement (Pearson’s correlation coefficients ≥0.9)
with benchtop selective reagent ionization time-of-flight mass spectrometry
(SRI-TOF-MS). As a result, an inexpensive sensor array is presented
that can be integrated readily into hand-held or even drone-carried
detectors for first responders to rapidly screen affected terrain