Forensic Science: Current State and Perspective by a Group of Early Career Researchers

© 2016, Springer Science+Business Media Dordrecht. Forensic science and its influence on policing and the criminal justice system have increased since the beginning of the twentieth century. While the philosophies of the forensic science pioneers remain the pillar of modern practice, rapid advances in technology and the underpinning sciences have seen an explosion in the number of disciplines and tools. Consequently, the way in which we exploit and interpret the remnant of criminal activity are adapting to this changing environment. In order to best exploit the trace, an interdisciplinary approach to both research and investigation is required. In this paper, nine postdoctoral research fellows from a multidisciplinary team discuss their vision for the future of forensic science at the crime scene, in the laboratory and beyond. This paper does not pretend to be exhaustive of all fields of forensic science, but describes a portion of the postdoctoral fellows’ interests and skills

Recent Trends Concerning Upconversion Nanoparticles and Near-IR Emissive Lanthanide Materials in the Context of Forensic Applications

Upconversion nanoparticles (UCNPs) are materials that, upon absorbing multiple photons of low energy (e.g. infrared radiation), subsequently emit a single photon of higher energy, typically within the visible spectrum. The physics of these materials have been the subject of detailed investigations driven by the potential application of these materials as medical imaging devices. One largely overlooked application of UCNPs is forensic science, wherein the ability to produce visible 5 light from infrared light sources would result in a new generation of fingerprint powders that circumvent background interference which can be encountered with visible and ultraviolet light sources. Using lower energy, infrared radiation would simultaneously improve the safety of forensic practitioners who often employ light sources in less than ideal locations. This review article covers the development of UCNPs, the use of infrared radiation to visualise fingerprints by the forensic sciences, and the potential benefits of applying UCNP materials over current approaches

CdS/polymer nanocomposites synthesized via surface initiated RAFT polymerization for the fluorescent detection of latent fingermarks

Current advances in nanoscience have provided the unique opportunity to utilize nanostructured materials to improve the visualization and quality of fingermark development. Here, we show the facile controlled fabrication of CdS/poly(dimethylacrylamide), CdS/poly(dimethylacrylamide-co-methyl methacrylate) and CdS/poly(dimethylacrylamide-co-styrene) fluorescent quantum dot nanocomposites for use as latent fingermark developing agents on non-porous surfaces. First, CdS quantum dots were capped with 2-mercaptoethanol with subsequent immobilization of a carboxylated C-12-chain transfer agent (C(12)CTA) via an ester bond. A surface initiated reversible addition fragmentation chain transfer (RAFT) polymerization was then performed under a controlled system resulting in nanocomposites containing polymers of low polydispersity. The intrinsic optical properties of the CdS quantum dots were retained throughout the synthetic pathways, which allowed for the successful one-step application and fluorescent visualization of latent fingermarks (fresh and aged) on aluminum foil and glass substrates under UV illumination

Surface initiated polydopamine grafted poly([2-(methacryoyloxy)ethyl]trimethylammonium chloride) coatings to produce reverse osmosis desalination membranes with anti-biofouling properties

Commercial polyamide (PA) reverse osmosis (RO) membranes were surface modified in a sequential two-step polymerization process to impart anti-biofouling properties to the membrane surface. In the first step, a 2-bromoisobutyryl bromide initiator-polydopamine (BiBBr-initiator-PDA) layer was deposited onto the membrane surface from a Tris(hydroxymethyl)aminomethane buffered solution of dopamine hydrochloride and 2-bromoisobutyryl bromide at ambient conditions. In the second step, polymer chains of [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MTAC) were grafted-from the BiBBr-initiator-PDA surface using activators regeneration by electron transfer-atom transfer radical polymerization for between 1 and 24 h. The modified surfaces were characterized using attenuated reflectance-Fourier transform infrared spectroscopy and water contact angle and their pure water flux, saline water flux and ability to reject salt were determined. Results showed that the water flux and salt rejection properties of the PDA-g-PMTAC modified membranes were similar to the unmodified PA RO membranes. Chlorine resistance tests showed the coating had enhanced stability in regards to salt rejection properties. Significantly, after six days of incubation in nutrient solution there was 93.2% less bacteria on the PDA-g-MTAC modified PA RO membranes, compared to the unmodified membranes

Non-toxic luminescent carbon dot/poly (dimethylacrylamide) nanocomposite reagent for latent fingermark detection synthesized via surface initiated reversible addition fragmentation chain transfer polymerization

Here, non-toxic luminescent carbon nanoparticles, namely carbon dots (C-dots), were facilely synthesized via a one-pot hydrothermal route. Raman, Fourier transform infrared, fluorescence, carbon NMR and X-ray photoelectron spectroscopies revealed that the C-dots possessed a graphitic-like core with an oxidized surface. The oxidized surface of the C-dots allowed for functionalization of the C-dots with a 2-methyl-2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid chain transfer agent. Poly(N,N-dimethylacrylamide) (p(DMA)) was then grafted from the C-dot surface via surface initiated reversible addition fragmentation chain transfer (RAFT) polymerization. The resulting luminescent C-dot/polymer nanocomposite, C-dot/p(DMA), was analyzed using UV-visible and fluorescence spectrometry verifying that the functionalized surface was responsible for the C-dots' luminescence. This C-dot/p(DMA) nanocomposite was water soluble and was used as a solution for the luminescent detection of latent fingermarks deposited on non-porous aluminium foil substrates

Design and direct additive manufacturing of three-dimensional surface micro-structures using material jetting technologies

The ability to directly print 3D microstructures across the surface of large dimension substrates opens up numerous possibilities not feasible with conventional 2D or 2.5D printing or coating techniques. Demonstrated herein is a method to print 3D microstructures onto clear poly(methyl methacrylate) (PMMA) plates using material jetting technologies. Contact angle and profilometry analysis indicated that the VeroCyan TM photopolymer had enhanced wetting of the PMMA surface leading to greater droplet spreading affecting the geometries printed compared to VeroCyan TM integrated models. Strategies to manipulate the interfacial interactions and hence adhesion of the VeroCyan TM photopolymer were investigated by varying PMMA surface free energy through physio-chemical and chemical techniques including (i) corona discharge, followed by post-treatments with 3-(trimethoxysilyl)propyl methacrylate, polyethyleneimine graft chemicals, and (ii) plasma treatments with air and plasma polymerisation of 1,7-octadiene. The surface chemistry and wetting behaviour played a crucial role in influencing interfacial interactions with the VeroCyan TM photopolymer hence its adhesion to the PMMA surface

Biocompatible anti-microbial coatings for urinary catheters

Using a simple dip-coating mechanism, urinary catheters have been coated with 2-poly(methacryloyloxy)ethyl]trimethylammonium chloride (pMTAC) using activator regenerated by electron transfer (ARGET) - atom transfer radical polymerization (ATRP). A polydopamine-2-bromoisobutyryl bromide (pDA-BiBBr) initiator was initially grafted-to the catheter surface to initiate polymerization resulting in a pDA-g-pMTAC coating. The pDA-g-pMTAC-coated catheters showed a significant reduction in bacterial adhesion, with respect to un-coated silicone catheters, as determined by analyzing microbiological assays as well as scanning electron microscopy images. At the same time, no evidence for cytotoxicity was observed, rather, the coating promoted cell adhesion and proliferation of human cells. This makes the coating attractive for temporary as well as permanently implanted medical devices

Reprogramming of the Circadian Clock by Nutritional Challenge

Circadian rhythms and cellular metabolism are intimately linked. Here, we reveal that a high-fat diet (HFD) generates a profound reorganization of specific metabolic pathways, leading to widespread remodeling of the liver clock. Strikingly, in addition to disrupting the normal circadian cycle, HFD causes an unexpectedly large-scale genesis of de novo oscillating transcripts, resulting in reorganization of the coordinated oscillations between coherent transcripts and metabolites. The mechanisms underlying this reprogramming involve both the impairment of CLOCK:BMAL1 chromatin recruitment and a pronounced cyclic activation of surrogate pathways through the transcriptional regulator PPARγ. Finally, we demonstrate that it is specifically the nutritional challenge, and not the development of obesity, that causes the reprogramming of the clock and that the effects of the diet on the clock are reversible