Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Glowing Fingerprints

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),
Title: Imaging Latent Fingerprints by Electrochemiluminescence
Angewandte Chemie International Edition, Permalink to the article:

Bin Su | Angewandte Chemie
Further information:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>