Detection of nitroaromatics in the solid, solution, and vapor phases using silicon quantum dot sensors.

Silicon quantum dots (Si-QDs) represent a well-known QD fluorophore that can emit throughout the visible spectrum depending on the interface structure and surface functional group. Detection of nitroaromatic compounds by monitoring the luminescence response of the sensor material (typically fluorescent polymers) currently forms the basis of new explosives sensing technologies. Freestanding silicon QDs may represent a benign alternative with a high degree of chemical and physical versatility.

Detection of high-energy compounds using photoluminescent silicon nanocrystal paper based sensors.

Luminescent silicon nanocrystals (Si-NCs) surface functionalized with dodecyl groups were exposed to solutions of nitroaromatic compounds including nitrobenzene, nitrotoluene, and dinitrotoluene. It was found that Si-NC luminescence was quenched upon exposure to nitroaromatics via an electron transfer mechanism as indicated by Stern-Volmer analysis. This quenching was exploited and a straightforward paper-based Si-NC sensor was developed.

Bridging the gap between the technological singularity and mainstream medicine: highlighting a course on technology and the future of medicine.

The "technological singularity" is defined as that putative point in time forecasted to occur in the mid twenty-first century when machines will become smarter than humans, leading humans and machines to merge. It is hypothesized that this event will have a profound influence on medicine and population health. This work describes a new course on Technology and the Future of Medicine developed by a diverse, multi-disciplinary group of faculty members at a Canadian university.

A convenient method for electron tomography sample preparation using a focused ion beam.

Here we report a new sample preparation method for three-dimensional electron tomography. The method uses the standard film deposition and focused ion beam (FIB) methods to significantly reduce the problems arising from the projected sample thickness at high tilt angles. The method can be used to prepare tomography samples that can be imaged up to a ±75° tilt range which is sufficient for many practical applications.