Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Glowing Fingerprints

01.08.2012
Researchers make latent fingerprints visible with help from electrochemiluminescence

Fingerprints are not just important in forensics and the identification of people; they can also be used for security clearance, access control, and the authentication of documents. In the journal Angewandte Chemie, Chinese researchers have now introduced a new fast method to make fingerprints visible at high resolution.



Fingerprints consist of sweat, oil, and compounds picked up from the environment. Latent fingerprints are often not identifiable with the naked eye; but many methods have been developed to make them visible. A team led by Bin Su at Zhejiang University (Hangzhou, China) has now added another interesting method to the mix. Their process is based on electrochemiluminescence.

Electrochemiluminescence consists of the following phenomenon: application of an electric voltage causes electrons transferred to an electrode from a chemical compound, such as a ruthenium complex, which further reacts with a partner, typically tripropylamine. The product formed is in an electronically excited state; it returns to its ground state by giving off light.

The researchers use a small glass plate coated with indium tin oxide or just a piece of stainless steel plate as the electrode. A fingerprint is transferred to this plate and then a solution containing the reactants is added. In the places where the fat-containing components of the fingerprint cover the plate, the electrode is inactive; the electrochemical reaction cannot take place, and no light is emitted. This produces a negative image of the fingerprint that can be recorded with a CCD camera.

This direct, fast, and simple method makes both fresh and old fingerprints visible without destroying them. The fingerprints are so well-resolved that it is possible to make out not only the ridge pattern, but also fine details like the branching and ends of lines, and even the tiniest features, like the distribution of pores in the grooves. These details are helpful in the identification of incomplete fingerprints. No complex procedures are needed to prepare the sample. In addition, there is no vapor or dusting involved for the user, unlike in many conventional processes.

Electrochemiluminescence can also be used in a second mode, which shows the fingerprint as a positive image. In this case, the fingerprints are first treated with a reagent that binds to components of the fingerprints. After the reaction partners are applied, only the lines emit light. This mode could be a starting point for the development of methods to detect drugs and other substances that the person who made the prints either ingested or came into contact with.

About the Author
Dr. Bin Su is a Research Professor at Zhejiang University (Hangzhou, China) with appointments in analytical chemistry and electrochemistry. His main interests are electrochemiluminescence imaging, electrochemical biosensors, and electrochemistry at liquid/liquid interfaces. He was the recipient of the Chinese Government Award for Outstanding Students Abroad in 2005.
Author: Bin Su, Zhejiang University, Hangzhou (China), http://mypage.zju.edu.cn/en/binsu/
Title: Imaging Latent Fingerprints by Electrochemiluminescence
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201203815

Bin Su | Angewandte Chemie
Further information:
http://pressroom.angewandte.org

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>