Tag Archives: human fingerprints

Fluorescent nanoparticles could transform how we visualize fingerprints

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It seems to be the day for fingerprints (see the first posting “Fingerprint detection improved with carbon-coated nanoparticles” published earlier today, September 17,2024).

This new technique announced in a September 12, 2024 news item on phys.org features fluorescent nanoparticles,

Researchers created a fluorescent nanoparticle using a combination of materials (MCM-41, chitosan and dansylglycine) to examine latent fingerprints. These nanoparticles have special properties that make them adhere well to fingerprint residues, even old ones.

The nanoparticles work on various surfaces, including metal, plastic, glass and complex objects such as polymer banknotes. They have the potential to be used directly at crime scenes without lab facilities, which is a significant advantage over some previous reagents. They produce high-quality fingerprint images, with the vast majority of those tested meeting the UK Home Office standards for a successful identification.

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Caption: Development of latent fingerprints. Representative images on stainless steel are shown, illuminated by and viewed under visible light (a) before development and (b) after development with MCM-41@Ch@DnsGly NPs. Corresponding images generated by illumination with UV light (λex = 365 nm) after MCM-41@Ch@DnsGly NP development are shown on (c) stainless steel, (d) glass, (e) plastic and (f) unfired brass cartridge case substrates. Credit: RSC Advances

A September 12, 2024 Diamond Light Source press release (also on EurekAlert), which originated the news item, provides more detail about the research and the international collaboration of scientists developing the new technique, Note: Links have been removed,

The research was published in a Royal Society of Chemistry paper, highlighting that the new nanomaterial has proven to be a versatile and effective tool for visualising fingermark evidence. Small angle X-ray scattering (SAXS) techniques at Diamond provided useful data to validate these results.

The research team includes scientists from the Technical and Scientific Section of Alagoas, Federal Police, Brazil; the National Institute of Criminalistics of the Federal Police, Brazil; the University of Leicester’s School of Chemistry; the Federal University of Alagoas, Brazil; and the UK’s national synchrotron, Diamond Light Source. 

Ridge patterns on fingertips remain unchanged during and beyond a person’s life. They provide the primary method of personal identification in criminal investigations. When an object’s surface is touched by a finger, sweat and oily substances are transferred and deposited onto the surface, resulting in the formation of a mark. Most fingermarks are invisible to the naked eye and are referred to as latent fingermarks.

The international collaboration of researchers developed the new nanostructured hybrid material, MCM-41@chitosan@dansylglycine, to visualise latent fingermarks. This material combines mesoporous silica nanoparticles with a fluorescent dye (dansylglycine) and chitosan, a polysaccharide derived from the exoskeletons of shrimps, crabs and lobsters.

Latent fingermarks require physicochemical development techniques to enhance their visibility and make them interpretable for forensic purposes. Traditional methods for developing fingerprints include optical, physical, and chemical processes that involve interaction between the developing agent (often a coloured or fluorescent reagent) and the fingermark residue. These methods have limitations in recovering high-quality results in certain conditions.

Recently, new methods using mass spectrometry, spectroscopy, electrochemistry, and nanoparticles have improved the development of latent fingermarks. These techniques offer better contrast, sensitivity, and selectivity, with low toxicity. The ability to adjust nanomaterial properties further enhances the detection of both fresh and aged fingermarks.

Mesoporous silica nanoparticles (MSNs) have attracted significant interest since the discovery of the M41S family of molecular sieves, which encompasses MCM-41, MCM-48, and SBA-15. These nanoparticles are characterised by their controlled particle size, porosity, high specific surface area, chemical stability, and ease of surface functionalisation.

Profa. Adriana Ribeiro, Federal University of Alagoas comments: “There are few studies employing chitosan for detection and enhancement of latent fingerprints and, to the best of our knowledge, no reports of the use of hierarchically structured MSNs modified with chitosan (MSN@Ch) for such applications – which was our strategy in this research. We exploited the MCM’s desirable characteristics – notably high surface area and surface modification – for the case of MCM-41 to enhance the interaction between the development reagent and fingerprint residue.”

The team added dansyl fluorophores which exhibit intense absorption bands in the near UV region and emit strong fluorescence in the visible spectrum with high emission quantum yields.

Professor of Physical Chemistry, Robert Hillman, University of Leicester concludes: “The overarching aim of this study was to create a versatile and effective latent fingermark visualisation material based on MSNs, chitosan and dansyl derivatives. These nanoparticles were applied as latent fingermark developers for marks on surfaces of diverse chemical composition, topography, optical characteristics and spatially variant nature, typical of forensically challenging evidence. For quality assessment of the enhanced fingermarks, we analysed the developed images using the UK Home Office scale, forensic protocols and, in terms of their constituent features, (minutiae), specialist forensic software. Across a substantive collection of marks deposited on chemically diverse surfaces and subject to complex environmental and temporal histories, the overwhelming majority of the enhanced images presented sufficient minutiae for comparison with model dactyloscopy images.”

Diamond Light Source CEO Prof. Gianluigi Botton adds: “It is pleasing to see that Diamond’s unique analytical tools once again have delivered outstanding science. Our network of international users is key to making sure our science delivers results. This advance in nanomaterials could be a step change in how forensics may be applied in the future.”

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Diamond Light Source provides industrial and academic user communities with access to state-of-the-art analytical tools to enable world-changing science. Shaped like a huge ring, it works like a giant microscope, accelerating electrons to near light speeds, to produce a light 10 billion times brighter than the Sun, which is then directed off into 33 laboratories known as ‘beamlines’. Additionally, Diamond offers access to several integrated laboratories including the world-class Electron Bio-imaging Centre (eBIC) and the Electron Physical Science Imaging Centre (ePSIC).  

Diamond serves as an agent of change, addressing 21st century challenges such as disease, clean energy, food security and more. Since operations started, more than 16,000 researchers from both academia and industry have used Diamond to conduct experiments, with the support of approximately 760 world-class staff. Almost 12,000 scientific articles have been published by its users and scientists.  

Funded by the UK Government through the Science and Technology Facilities Council (STFC), and by the Wellcome Trust, Diamond is one of the most advanced scientific facilities in the world, and its pioneering capabilities are helping to keep the UK at the forefront of scientific research.  

Diamond was set-up as an independent not for profit company through a joint venture, between the UKRI’s Science and Technology Facilities Council and one of the world’s largest biomedical charities, the Wellcome Trust – each respectively owning 86% and 14% of the shareholding.  

The University of Leicester is led by discovery and innovation – an international centre for excellence renowned for research, teaching and broadening access to higher education. It is among the Top 30 universities in the Times Higher Education (THE)’s Research Excellence Framework (REF) 2021 rankings with 89% of research assessed as world-leading or internationally excellent, with wide-ranging impacts on society, health, culture, and the environment. In 2023, the University received an overall Gold in the Teaching Excellence Framework (TEF) 2023, making it one of a small number of institutions nationally to achieve TEF Gold alongside a top 30 REF performance. The University is home to more than 20,000 students and approximately 4,000 staff.

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Federal University of Alagoas (UFAL) Located in the city of Maceió, the Federal University of Alagoas (UFAL) is the major University in coastal state Alagoas.  It is currently considered one of the main research centers in the Brazilian Northeast region. The Federal University of Alagoas (UFAL) is a national reference in teaching, research and extension activities, establishing itself as an excellent support for the demands of society. It is the largest public higher education institution in the state of Alagoas and was ranked 49th among the best universities in Brazil in the 2023 edition of the World University Rankings (CWUR).  One of the reasons for reaching this level was the impact of institutional support and investment in research. All of this is the result of the prioritization of research at the University over the last four years, which is reflected in quality teaching and service. UFAL has 82.1% of its publications with national and international collaboration. And most of the citations were from works produced with researchers from other countries.

Here’s a link to and a citation for the paper,

Dansyl fluorophore functionalized hierarchically structured mesoporous silica nanoparticles as novel latent fingerprint development agents by Lais F. A. M. Oliveira, Lais V. A. T. da Silva, Artur F. Sonsin, Meclycia S. Alves, Cristiane V. Costa, Jeane C. S. Melo, Nicholas Ross, Paul T. Wady, Thomas Zinn, Ticiano G. do Nascimento, Eduardo J. S. Fonseca, Alexandro M. L. de Assis, A. Robert Hillman and Adriana S. Ribeiro. RSC Adv., 2024,14, 22504-22512 DOI: DOI: https://doi.org/10.1039/D4RA03074E First published: 17 Jul 2024

This article is open access.

Fingerprint detection improved with carbon-coated nanoparticles

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Fig. 7. Fingerprint ridge patterns of WLC-Mn-Fe2O3 nanocomposite powder obtained on aluminium foil at daylight. Courtesy: Researchers and Hybrid Advances journal

South African researchers have developed a new technique for detecting fingerprints according to a June 17, 2024 news item by Samuel Jarman on phys.org (or you can see the originating June 17, 2024 press release by Jarman of sciencpod on behalf of the Nelson Mandela University), Note: Links have been removed,

Fingerprint detection is one of the most important techniques in forensic investigation. When fingerprints are dusted with a carbon-based powder, the material will adhere to the moisture and grease left behind by the unique patterns of ridges and valleys on the perpetrator’s fingertip. The resulting pattern can then be analyzed under a microscope, and compared with suspects’ fingerprints.

Researchers led by Bienvenu Gael Fouda-Mbanga at Nelson Mandela University, Gzeberha, South Africa, have discovered a new type of powder for dusting fingerprints. It allowed them to image their nanoscale details more clearly, while deepening the contrast between ridges and valleys. This work is now published in Hybrid Advances.

Made from manganese-doped iron oxide nanoparticles, and coated in an activated wool char, this new material could help forensic investigators solve crimes more easily.

Recently, metal-oxide nanoparticles have become increasingly popular in fingerprint detection. Not only are they easy to produce, but they also have a high surface area and chemical reactivity, allowing them to interact strongly with the chemical compounds contained in fingerprint residues. When coated in carbon, these nanoparticles create a deeper contrast in fingerprint images, making them far easier to analyse.

In their study, Fouda-Mbanga’s team fabricated their iron oxide nanoparticles using a low-cost, environmentally friendly ‘hydrothermal’ method. They then coated the particles with activated charred wool. This widely available agricultural waste product is chemically inert, making it safer to use than conventional carbon-based powders, while also enhancing the stability of the more reactive nanoparticles.

To examine their powder’s performance, the researchers used it to dust fingerprint residues on a non-porous aluminium surface. They then employed several different types of electron microscopy and light spectroscopy to image them.

The images they produced were incredibly promising, revealing details down to a nanoscale resolution while showing a starker contrast than many types of powder tested in previous studies. Following this success, Fouda-Mbanga’s team now hope that their approach to nanoparticle fabrication could soon be applied more widely in forensic investigation.

Here’s a link to and a citation for the paper,

Nanoarchitectonics of WLC-H3PO4–MnFe2O3 nanocomposite for latent fingerprint detection by B.G. Fouda-Mbanga, T. seyisi, K. Pillay, Zikhona TN. Hybrid Advances Volume 5, April 2024, 100122 DOI: https://doi.org/10.1016/j.hybadv.2023.100122 First Available online 5 December 2023, Version of Record 7 December 2023.

This paper is open access.

Nanowire fingerprint technology

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Apparently this technology from France’s Laboratoire d’électronique des technologies de l’information (CEA-Leti) will make fingerprinting more reliable. From a Sept. 5, 2017 news item on Nanowerk,

Leti today announced that the European R&D project known as PiezoMAT has developed a pressure-based fingerprint sensor that enables resolution more than twice as high as currently required by the U.S. Federal Bureau of Investigation (FBI).

The project’s proof of concept demonstrates that a matrix of interconnected piezoelectric zinc-oxide (ZnO) nanowires grown on silicon can reconstruct the smallest features of human fingerprints at 1,000 dots per inch (DPI).

“The pressure-based fingerprint sensor derived from the integration of piezo-electric ZnO nanowires grown on silicon opens the path to ultra-high resolution fingerprint sensors, which will be able to reach resolution much higher than 1,000 DPI,” said Antoine Viana, Leti’s project manager. “This technology holds promise for significant improvement in both security and identification applications.”

A Sept. 5, 2017 Leti press release, which originated the news item, delves further,

The eight-member project team of European companies, universities and research institutes fabricated a demonstrator embedding a silicon chip with 250 pixels, and its associated electronics for signal collection and post-processing. The chip was designed to demonstrate the concept and the major technological achievements, not the maximum potential nanowire integration density. Long-term development will pursue full electronics integration for optimal sensor resolution.

The project also provided valuable experience and know-how in several key areas, such as optimization of seed-layer processing, localized growth of well-oriented ZnO nanowires on silicon substrates, mathematical modeling of complex charge generation, and synthesis of new polymers for encapsulation. The research and deliverables of the project have been presented in scientific journals and at conferences, including Eurosensors 2016 in Budapest.

The 44-month, €2.9 million PiezoMAT (PIEZOelectric nanowire MATrices) research project was funded by the European Commission in the Seventh Framework Program. Its partners include:

  • Leti (Grenoble, France): A leading European center in the field of microelectronics, microtechnology and nanotechnology R&D, Leti is one of the three institutes of the Technological Research Division at CEA, the French Alternative Energies and Atomic Energy Commission. Leti’s activities span basic and applied research up to pilot industrial lines. www.leti-cea.com/cea-tech/leti/english
  • Fraunhofer IAF (Freiburg, Germany): Fraunhofer IAF, one of the leading research facilities worldwide in the field of III-V semiconductors, develops electronic and optical devices based on modern micro- and nanostructures. Fraunhofer IAF’s technologies find applications in areas such as security, energy, communication, health, and mobility. www.iaf.fraunhofer.de/en
  • Centre for Energy Research, Hungarian Academy of Sciences (Budapest, Hungary):  The Institute for Technical Physics and Materials Science, one of the institutes of the Research Centre, conducts interdisciplinary research on complex functional materials and nanometer-scale structures, exploration of physical, chemical, and biological principles, and their exploitation in integrated micro- and nanosystems www.mems.hu, www.energia.mta.hu/en
  • Universität Leipzig (Leipzig, Germany): Germany’s second-oldest university with continuous teaching, established in 1409, hosts about 30,000 students in liberal arts, medicine and natural sciences. One of its scientific profiles is “Complex Matter”, and contributions to PIEZOMAT are in the field of nanostructures and wide gap materials. www.zv.uni-leipzig.de/en/
  • Kaunas University of Technology (Kaunas, Lithuania): One of the largest technical universities in the Baltic States, focusing its R&D activities on novel materials, smart devices, advanced measurement techniques and micro/nano-technologies. The Institute of Mechatronics specializes on multi-physics simulation and dynamic characterization of macro/micro-scale transducers with well-established expertise in the field of piezoelectric devices. http://en.ktu.lt/
  • SPECIFIC POLYMERS (Castries, France): SME with twelve employees and an annual turnover of about 1M€, SPECIFIC POLYMERS acts as an R&D service provider and scale-up producer in the field of functional polymers with high specificity (>1000 polymers in catalogue; >500 customers; >50 countries). www.specificpolymers.fr/
  • Tyndall National Institute (Cork, Ireland): Tyndall National Institute is one of Europe’s leading research centres in Information and Communications Technology (ICT) research and development and the largest facility of its type in Ireland. The Institute employs over 460 researchers, engineers and support staff, with a full-time graduate cohort of 135 students. With a network of 200 industry partners and customers worldwide, Tyndall generates around €30M income each year, 85% from competitively won contracts nationally and internationally. Tyndall is a globally leading Institute in its four core research areas of Photonics, Microsystems, Micro/Nanoelectronics and Theory, Modeling and Design. www.tyndall.ie/
  • OT-Morpho (Paris, France): OT-Morpho is a world leader in digital security & identification technologies with the ambition to empower citizens and consumers alike to interact, pay, connect, commute, travel and even vote in ways that are now possible in a connected world. As our physical and digital, civil and commercial lifestyles converge, OT-Morpho stands precisely at that crossroads to leverage the best in security and identity technologies and offer customized solutions to a wide range of international clients from key industries, including Financial services, Telecom, Identity, Security and IoT. With close to €3bn in revenues and more than 14,000 employees, OT-Morpho is the result of the merger between OT (Oberthur Technologies) and Safran Identity & Security (Morpho) completed in 31 May 2017. Temporarily designated by the name “OT-Morpho”, the new company will unveil its new name in September 2017. For more information, visit www.morpho.com and www.oberthur.com

I have tended to take fingerprint technology for granted but last fall (2016) I stumbled on a report suggesting that forensic sciences, including fingerprinting, was perhaps not as conclusive as one might expect after watching fictional police procedural television programmes. My Sept. 23, 2016 posting features the US President’s Council of Advisors on Science and Technology (PCAST) released a report (‘Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods‘ 174 pp PDF).