Project Lead(s): John Davis
Disease diagnoses that require microscopy or cell culturing are not ideal for rural healthcare clinics, where people often walk long distances and need to return home quickly.
There is need to develop tools that would provide an instantaneous diagnosis that is based on a simple, non-invasive breath analysis.
Such diagnostic tools would allow health practitioners in rural clinics in low- and middle-income countries to identify the best treatment, rather than making a fast or easy diagnosis out of fear that the patient will leave the clinic and not return.
The aim of the project was to develop a prototype, hand-held breath analysis system for volatile organic compounds (VOCs), similar to a breathalyzer used to detect alcohol consumption.
This breathalyzer would be sensitive to many VOCs with different responses for different molecules.
A patient would breath into the hand-held device, which would analyze the breath and determine which biomarker VOCs were present and in what amounts.
The team worked to identify and develop the different components necessary to develop a working prototype of a hand-held breath analysis system for VOCs.
Photothermal spectroscopy provides a spectroscopic fingerprint of the molecule, which is unavailable using mass adsorption/desorption alone. This approach was used to identify VOCs on nanostrings, which were functionalized to capture target small molecules.
The team is now trying to combine functionalized nanostrings with photothermal spectroscopy.
They demonstrated that femtogram-scale quantities of the explosive molecule 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) could be detected through a combination of nanomechanical photothermal spectroscopy and mass desorption.
Their measurement, based on thermomechanical measurement of silicon nitride nanostrings, represents the highest mass resolution ever demonstrated via nanomechanical photothermal spectroscopy.
The team also showed that the particular distribution of mass deposited on the surface of a nanomechanical resonator can be estimated by tracking the evolution of the device’s resonance frequencies during the process of desorption. This detection scheme is quick, label-free and compatible with parallelized molecular analysis of multicomponent targets.
The team was also working to miniaturize the device.
While the team was unable to develop a prototype during the grant period, they have received additional provincial funding through the Government of Alberta (Canada), as a part of the Alberta Innovates Technology Futures (AITF) iCORE Chair, and from the Alberta Innovates Health Solutions (AIHS) Collaborative Research and Innovation Opportunities (CRIO) to continue this project.