Spontaneous Droplet Formation using Surface Energy Traps (SETs)
The Namib Desert Beetle (Stenocara gracilipe) has evolved an interesting method to collect water in an arid environment. The beetle’s back is patterned with regions that wet differently when contacted with morning fog. Hydrophilic regions collect water droplets, and when the droplets are large enough, they detach and slide along hydrophobic regions to the beetle’s mouth.
Similarly, we can utilize patterned surfaces for analytical chemistry applications. Surfaces can be patterned with hydrophilic and omniphobic regions so that respond differently when contacted with water or other solvents. Those areas that are wetted trap fluid (this is why they are referred to as surface energy traps). We have used laser micromachining, photolithography and plasma exposure to alter the wetting characteristics. By controlling the wetting areas we can precisely control the volume of fluid rapidly deposited when it is contacted with a wetting solution. We can use this phenomenon (named discontinuous de-wetting) to carry out droplet applications for analytical chemistry measurements. The shape and size of the SETs can be used to direct the fluids.
Selected Publications on Surface Energy Traps
Discontinuously Dewetting Solvent Arrays: Droplet Formation and Poly-Synchronous Surface Extraction for Mass Spectrometry Imaging Applications
Rapid Mass Spectrometric Calibration and Standard Addition Using Hydrophobic/Hydrophilic Patterned Surfaces and Discontinuous Dewetting
Ambient Ionization Mass Spectrometry
The Oleschuk group is dedicated to advancing the field of ambient ionization mass spectrometry. The group specifically focusses on the Liquid Microjunction Surface Sampling Probe (LMJ-SSP). Research in the group aims to explore the capability and applications of the LMJ-SSP for direct analysis of complex samples in their native environment. By integrating cutting edge research, we strive to enhance sensitivity, selectivity and spatial resolution in ambient ionization.
Selected publications on ambient ionization:
Hyperspectral Visualization-Based Mass Spectrometry Imaging by LMJ-SSP: A Novel Strategy for Rapid Natural Product Profiling in Bacteria
Detection of Opioids on Mail/Packages using Open Port Interface Mass Spectrometry (OPI-MS)
3D Printing
In the Oleschuk group, we are interested in exploring the applications of 3D printing in mass spectrometry. We aim to develop innovative and cost-effective ways to create custom components to help with our research. This may include designing and fabricating sample introduction systems, and other components. In utilizing 3D printing in the Oleschuk group, we hope to improve the accessibility and versatility of mass spectrometry.
Selected Publications on 3D Printing:
Leveraging 3D printing to enhance mass spectrometry: A Review
Diagnostic Imaging Surface Analysis
The three pillars of cancer treatment are surgery, radiation, and chemotherapy. Of the three pillars, traditional tissue and tumour analysis in surgery has adopted the “bread loafing” method
Whereby the tumour is sliced in multiple sections and is annotated by a pathologist for a positive (cancerous) or negative (non-cancerous) margin. This can be a time-consuming process which can also provide stress for the patient as they may have to undergo surgery once again. As such, mass spectrometry shows promise for improving tumour margin detection.
In the Oleschuk group, tissue imaging is performed with aforementioned surface energy traps, and polysynchronous solvent extraction. Using SETs, tumour sections can be stamped with the SETs and a heat map can be generated of areas of interest.
Selected Publications on Diagnostic Imaging Surface Analysis: