Heavy metals are a major public health concern and their on-site detection in water supplies is not well served by existing lab techniques. We develop a new multi-modal platform comprising functionalized quantum dots of two-dimensional materials (2D-QDs) for the sensing of four highly-toxic heavy metal pollutants (arsenic, cadmium, lead and mercury). The zero-dimensional nature of quantum dots brings essential properties necessary for fluorescence-based chemical sensing of heavy metals in the field. We focus on one type of 2D material, molybdenum disulfide (MoS2), which is a direct band gap semiconductor when produced as a monolayer. To fabricate and functionalize the 2D-QDs, we expose flakes of MoS2 suspended in a solution to a pulsed laser. This technique allows us to simultaneously functionalize the 2D-QDs, so that they become sensitive to a specific pollutant metal, and control their fluorescence wavelength, so that 2D-QDs functionalized for different target metals will produce distinguishable optical signals. By combining multiple types of functionalized 2D-QDs into a single solution capable of simultaneously identifying various heavy metals, we expect to advance a range of applications that require a field-deployable solution. These include for example, rapid contaminant point source identification, and water analysis of heavy metals in developing countries where conventional equipment is too costly.
Molecular Scale Magnetic Resonance Imaging
Through its phenomenal ability to image soft tissues, magnetic resonance imaging (MRI) has revolutionized both clinical medicine and research biomedicine.
September 9, 2016
Repurposing potential drug candidates for the treatment of COVID-19
Summary The main protease (Mpro) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the coronavirus disease (COVID-19), has emerged as a promising drug target. The scientific community has produced a large number of crystallographic structures of the protease, which mediates viral replication and transcription. These structures report several fragments with varied chemotypes […]
May 6, 2020
Hybrid Quantum Materials towards Topological Quantum Computing
Summary Proximity engineered hybrid materials have shown promise for topological quantum information processing. This form of quantum computing provides a stable, error-tolerant approach for building scalable quantum information processors. Topological quantum computing relies on braiding non-Abelian particles, such as Majorana fermions, which do not exist in nature. One can however use materials engineering to […]
December 8, 2018
Line-Scanning optical coherence tomography system for in-vivo, non-invasive imaging of the cellular structure and blood perfusion of biological tissue
Summary Optical coherence tomography (OCT) is an optical imaging method that allows for in-vivo, non-invasive imaging of the structure and vasculature of biological tissue. Commercially available, clinical OCT systems utilize point-scanning method to acquire volumetric images over a large surface with typical frame rates of ~ 30 frames/ second. Since living biological tissue is constantly […]
August 27, 2019