Skip to content
Skip to content
  • News
  • Events
  • eBooks
  • Blog
  • Careers
  • Contact
  • News
  • Events
  • eBooks
  • Blog
  • Careers
  • Contact
KNOWLEDGEBASE
  • About Us
  • Products

    Fluorescence Spectrometers

    • FLS1000 Photoluminescence Spectrometer
    • FS5 Spectrofluorometer
    • LifeSpec II Lifetime Spectrometer
    • Mini-tau Lifetime Spectrometer

    Raman Microscopes

    • RM5 Raman Microscope
    • RMS1000 Multimodal Confocal Microscope

    Transient Absorption

    • LP980 Transient Absorption Spectrometer

    FTIR Spectrometers

    • IR5 FTIR Spectrometer

    Lasers and LEDs

    • Pulsed Lasers
    • Gas Lasers
    • Customisation Options
    View All Products
  • Techniques
  • Applications
KNOWLEDGEBASE
Edit Content
  • About Us
  • Products
  • Techniques
  • Applications
  • Knowledgebase
  • eBooks
  • News
  • Events
  • Blog
  • Careers
  • Contact Us
  1. Home
  2. Blog Post
  3. Bank Note Analysis with Edinburgh Instruments

BLOG

Bank Note Analysis with Edinburgh Instruments

  • November 26, 2021
Edit Content

Manufacturers of bank notes will use specific and unique dyes which helps to keep authentic bank notes in circulation and aids the identification of forgeries. The dyes will have different photoluminescence (PL) emission, excitation, and lifetimes which can be used for authenticity checks. This blog post briefly details how Edinburgh Instruments RMS1000 Confocal Raman & PL Microscope and FS5 Spectrofluorometer can be used to aid banks in detecting fraudulent bank notes.

Photoluminescence Mapping using the RMS1000

We can utilise PL on our Raman microscopes to investigate bank notes. Using an RMS1000 Raman Microscope equipped with a 532 nm laser at 0.1% power and a 300 gr/mm grating, we looked at a Scottish Bank note to show how PL can distinguish between the two fluorophores in the sample. The low power is used due to the strength of the PL signal in comparison to typical Raman counts observed. A low groove density grating allows for the full PL spectra to be acquired with the 532 nm laser. We can then PL map the sample using the motorised stage in the same way as Raman mapping with Ramacle®.

Photoluminescence measured using a confocal Raman microscope for bank note analysis

Figure 1: a) Clydesdale Bank note, b) top – image of area to be mapped, bottom – PL map, c) spectra from the PL map

Figure 1a) shows the sample that was placed under the microscope, a £20 Clydesdale Bank polymer note bearing the portrait of Scottish king Robert the Bruce. An area of his beard, top figure 1b), was chosen for PL mapping. The PL map, bottom figure 1b), is coloured with the two PL contributions, one in green and one in red based on their peak wavelengths. These spectra are shown in Figure 1c) where it is clear to see the two PL contributions have significantly different peak positions. This a rapid way to check the authenticity of a bank note during forensic analysis under a Raman microscope to show the PL is occurring at the expected wavelength.

Spectra and Lifetime Measurements using the FS5

Australian 5-dollar bank notes have an eye catching photoluminescent security label of a bird perched on a branch that emits when excited with UV light (Figure 2a). Using an FS5 Spectrofluorometer we can aquire the spectra and lifetime of the phosphors used in this label can be measured (Figure 2b).

Photoluminescent security label of Australian bank note under UV excitation.

Figure 2: a) Australian $5 Bank note and b) photoluminescent security label under UV excitation.

The bank note was excited at 300 nm using the Xenon lamp of the FS5 and the emission spectra of the red and green regions measured as shown in Figure 3a) and 3b) respectively. The signature peaks and line shape of the emission from the two phosphors can be used to confirm authenticity.

Emission spectra from a bank note

Figure 3: Photoluminescence emission spectrum of the a) red emitting region and b) green emitting region. λex = 300 nm.

Another signature feature of phosphors is their radiative lifetimes. Using the Xenon flashlamp of the FS5, the phosphorescence decay of both phosphors was measured and shown in Figure 4a) and 4b). Both decays have an initial fast component due to fluorescence followed by a longer tail which is the phosphorescence emission. The tail regions of both decays were fit using the Fluoracle software of the FS5 to reveal a lifetime of 830 µs for the red phosphor and 2.1 ms for the green. This provides a second signature mark of the phosphor identity and authenticity.

Photoluminescence lifetimes from a bank note

Figure 4: Photoluminescence lifetime of a) the red emitting region measured using MCS mode with the microsecond flashlamp, λex = 300 nm, λem = 621 nm, and b) the green emitting region measured using MCS mode with the microsecond flashlamp, λex = 300 nm, λem = 550 nm.

Conclusion

PL measurements provide distinguishing spectral and lifetime information for the different security tags used on bank notes, making it ideally suited for authenticity analysis. Our range of spectrofluorometers and Raman microscopes can be configured to easily investigate potential forgeries, as well as aid in development of new bank notes by providing ID profiles of new security tags.

Discover Edinburgh Instruments Spectrometers

If you want to know how our FS5 Spectrofluorometer or RMS1000 Raman Microscope can help with your security and fraud applications please contact us, a member of our sales team will be happy to discuss our range of instruments.

RELATED PRODUCTS

MicroPL

Spectromicroscopy Upgrade

VIEW

RMS1000

Multimodal Confocal Microscope

VIEW

RM5

Raman Microscope

VIEW

FS5

Spectrofluorometer

VIEW

RESOURCES

Tags:
  • Forensics
  • RM5
  • RMS1000
  • Raman
Suggested Reading:

Forensic Analysis using Confocal Raman and Photoluminescence Microscopy

View more »
Share:
PrevPrevious
NextNext

Keep up to date with the latest from Edinburgh Instruments

Join our mailing list and keep up with our latest videos, app notes and more!

LOCATION:
  • Edinburgh Instruments Ltd.
    2 Bain Square, Kirkton Campus, Livingston, EH54 7DQ.
  • sales@edinst.com
  • +44 1506 425 300
ABOUT:
  • About Us
  • Techniques
  • Applications
  • Knowledgebase
  • About Us
  • Techniques
  • Applications
  • Knowledgebase
PRODUCTS:
  • Fluorescence Spectrometers
  • Raman Microscopes
  • UV-Vis Spectrophotometers
  • Transient Absorption
  • FTIR Spectrometers
  • Lasers and LEDs
  • Customisation Options
  • Software
  • Upgrades
  • All Products
  • Fluorescence Spectrometers
  • Raman Microscopes
  • UV-Vis Spectrophotometers
  • Transient Absorption
  • FTIR Spectrometers
  • Lasers and LEDs
  • Customisation Options
  • Software
  • Upgrades
  • All Products
LEGALS:
  • News
  • Events
  • Blog
  • Careers
  • Contact Us
  • Terms and Conditions
  • Privacy Policy
  • News
  • Events
  • Blog
  • Careers
  • Contact Us
  • Terms and Conditions
  • Privacy Policy
SOCIALS:
Youtube Linkedin X-twitter Facebook
©2024 Edinburgh Instruments. Registered in England and Wales No: 962331. VAT No: GB 271 7379 37
Manage Consent
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behaviour or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Manage options Manage services Manage {vendor_count} vendors Read more about these purposes
View preferences
{title} {title} {title}