Fingermark detection using upconverting nanoparticles and comparison with cyanoacrylate fuming

Fingermark quality assessment, a transversal study of subjective quality scales

Fingermark detection research aims to improve the quantity and quality of fingermarks detected through the development of novel techniques. Subsequently, there is a need to evaluate these methods to determine the quality of the developed mark. Since the 1980's there has been a significant number of publications, which utilise a variety of different quality assessment methods. The introduction of common practice methods from the International Fingerprint Research Group (IFRG) aimed to implement a more standardised approach. Although these schemes are recommended as common practice, they are only guidelines. Consequentially, there is currently no universally accepted method to evaluate the enhancement techniques implemented in research. Therefore, this study aimed to collate and analyse the published protocols being used within fingermark detection research in order to better understand their application and how research is currently analysing and interpreting fingermark quality. This study comprised of manual and automatic searches of over 2000 published papers within the fingermark detection area. After thorough analysis of the articles, 396 published papers were found to have used a scale within the years spanning 1998-2022. The number of publications that report the use of a scale to assess quality for fingermark detection research has considerably increased over the last decade. However, whilst the number of publications utilising scales has increased, it is not proportional to the number of papers using the IFRG scales. The choice of scale is often institution specific and even more specific to their location. There are also numerous different adaptations of the IFRG recommended scales, as well as novel scales, which do not associate with the IFRG recommended versions being introduced the more research continues to grow. One such reason for this is investigated here, as different quality parameters are utilised within each individual scale. There is underrepresentation of these quality parameters within some of the IFRG scales, in particular the Centre for Applied Science and Technology (CAST) scale. This correlates to the considerable number of tailored approaches as authors are forced to add these parameters within the descriptions. Until there is an introduction of clear guidelines surrounding all areas of fingermark quality, from definition to parameters chosen within phases, the research area will continue to face such issues. This article recommends areas of potential study, whilst also recommending procedures that may be employed to alleviate some of the issues seen with fingermark quality evaluation.

Surface-enhanced Raman imaging through sprayed probes for the application in chemical visualization of methamphetamine within fingerprints

For fingerprint-involved forensic investigations, cyanoacrylates and inorganic nanophosphors are mostly used for fingerprint visualization. However, methods to simultaneously report fingerprint images and the corresponding specific chemical information have yet to be realized. In this work, chemical visualization of the analytes in fingerprints is achieved through surface-enhanced Raman spectroscopy (SERS) measurements with the aid of spray-dispersed gold nanorods (AuNRs). The optimal coverage of AuNRs was studied by theoretical simulations and experimental operations. A rapid sampling of fingerprints with the chemical of interest was developed by tuning the spray parameters. In particular, the SERS imaging of methamphetamine in fingerprint latent was attempted by addressing the SERS spectral features of methamphetamine. This chemical visualization method reflects both the graphical and chemical characteristics of fingerprints in a single batch measurement, in which methamphetamine can be detected and mapped at the concentration of 10^-5 M. The data processing approach was also modified by employing relevant logical judgments. The improved SERS images with sharpened patterns of fingerprints were obtained by involving the scored multi-peak judgments.

Lanthanide-Doped Upconversion Nanoparticles: Exploring A Treasure Trove of NIR-Mediated Emerging Applications

Lanthanide-doped upconversion nanoparticles (UCNPs) possess the remarkable ability to convert multiple near-infrared (NIR) photons into higher energy ultraviolet-visible (UV-vis) photons, making them a prime candidate for several advanced applications within the realm of nanotechnology. Compared to traditional organic fluorophores and quantum dots (QDs), UCNPs possess narrower emission bands (fwhm of 10-50 nm), large anti-Stokes shifts, low toxicity, high chemical stability, and resistance to photobleaching and blinking. In addition, unlike UV-vis excitation, NIR excitation is nondestructive at lower power intensities and has high tissue penetration depths (up to 2 mm) with low autofluorescence and scattering. Together, these properties make UCNPs exceedingly favored for advanced bioanalytical and theranostic applications, where these systems have been well-explored. UCNPs are also well-suited for bioimaging, optically modulating chemistries, forensic science, and other state-of-the-art research applications. In this review, an up-to-date account of emerging applications in UCNP research, beyond bioanalytical and theranostics, are presented including optogenetics, super-resolution imaging, encoded barcodes, fingerprinting, NIR vision, UCNP-assisted photochemical manipulations, optical tweezers, 3D printing, lasing, NIR-II imaging, UCNP-molecule nanohybrids, and UCNP-based persistent luminescent nanocrystals.