Hyperspectral-Assisted Scanning Electrochemical Microscopy for Single Cell Analysis

As the scope of our knowledge surrounding cell response to stimuli widens, the value in an unambiguous understanding of cell-to-cell heterogeneity increases. The advancement of biological imaging relies on studying the smallest unit of life – a single, living cell. Scanning electrochemical microscopy (SECM) has served as a non-destructive method for imaging single cells with most biological platforms being equipped with correlated optical and fluorescence microscopy. While fluorescence microscopy has served as a minimally destructive method for analysis, it may also be compromised by low signal-to-noise and phototoxic effects. To overcome these barriers in live-cell microscopy, we combine a typical biological SECM platform with a variable fluorescence bandpass source for obtaining electrochemical, optical, and spectral data, simultaneously. Our novel imaging platform widens the scope of biological imaging by allowing one to capture spectral data with 1 nm resolution to probe dynamic extra- and intra-cellular interactions via hyperspectral-assisted SECM. To demonstrate the robust capabilities and versatility of our imaging platform, we use hyperspectral-assisted SECM to examine a two-dimensional co-culture system and to investigate two relevant public health concerns: the mechanism of human cytomegalovirus propagation and the mechanism of perfluorooctane sulfonate cytotoxicity within two-dimensional tissue cultures.Doctor of Philosoph

Electrosynthesis of high-entropy metallic glass nanoparticles for designer, multi-functional electrocatalysis

International audienceCreative approaches to the design of catalytic nanomaterials are necessary in achieving environmentally sustainable energy sources. Integrating dissimilar metals into a single nanoparticle (NP) offers a unique avenue for customizing catalytic activity and maximizing surface area. Alloys containing five or more equimolar components with a disordered, amorphous microstructure, referred to as High-Entropy Metallic Glasses (HEMGs), provide tunable catalytic performance based on the individual properties of incorporated metals. Here, we present a generalized strategy to electrosynthesize HEMG-NPs with up to eight equimolar components by confining multiple metal salt precursors to water nanodroplets emulsified in dichloroethane. Upon collision with an electrode, alloy NPs are electrodeposited into a disordered microstructure, where dissimilar metal atoms are proximally arranged. We also demonstrate precise control over metal stoichiometry by tuning the concentration of metal salt dissolved in the nanodroplet. The application of HEMG-NPs to energy conversion is highlighted with electrocatalytic water splitting on CoFeLaNiPt HEMG-NPs