Time-resolved fluorescence microscopy of gunshot residue: an application to forensic science

Time-resolved fluorescence microscopy has rapidly emerged as the technique of choice for many researchers aiming to gain specific insights into the dynamics of intricate biological systems. Although the unique advantages the technique provides over other methods have proven to be particularly useful in the biosciences, to date they have been largely unexploited by other research disciplines. In this paper, we demonstrate the capacity of time-resolved fluorescence microscopy as a practical analytical tool in the forensic sciences via the imaging of gunshot residues that are expelled when a firearm is discharged. This information may prove to be useful for determination of the true sequence of events that took place in a firearm related crime.

Atomically resolved tomography to directly inform simulations for structure-property relationships

Microscopy encompasses a wide variety of forms and scales. So too does the array of simulation techniques developed that correlate to and build upon microstructural information. Nevertheless, a true nexus between microscopy and atomistic simulations is lacking. Atom probe has emerged as a potential means of achieving this goal. Atom probe generates three-dimensional atomistic images in a format almost identical to many atomistic simulations. However, this data is imperfect, preventing input into computational algorithms to predict material properties. Here we describe a methodology to overcome these limitations, based on a hybrid data format, blending atom probe and predictive Monte Carlo simulations. We create atomically complete and lattice-bound models of material specimens. This hybrid data can then be used as direct input into density functional theory simulations to calculate local energetics and elastic properties. This research demonstrates the role that atom probe combined with theoretical approaches can play in modern materials engineering.

Potential-resolved electrogenerated chemiluminescence for the selective detection of multiple luminophores

Electrogenerated chemiluminescence (ECL) is fundamentally dependent on the applied electrode potential, and measuring ECL intensity over a range of different potentials is commonly used to examine the underlying chemical reaction pathways responsible for the emission of light. Several research groups have now demonstrated that the applied potential can be exploited to selectively elicit ECL from: 1) multiple excited states within a single chemical species; 2) multiple emitters sharing a common co-reactant; or 3) distinct ECL systems. This new generation of multiplexed ECL processes has been facilitated by the extensive development of novel electrochemiluminophores and instrumental approaches such as the near-continuous collection of ECL spectra with CCD detectors during voltammetry or chronoamperometry experiments. New dimensions: In electrogenerated chemiluminescence experiments the applied potential can be exploited to selectively elicit light from: multiple excited states within a single chemical species, multiple emitters sharing a common co-reactant, and distinct electrogenerated chemiluminescence systems. These findings may be used to develop low-cost portable analytical devices.