Bi-luminescent Security Ink


A “Bi-Luminescent Security Ink” has been discovered by the CSIR-National Physical Laboratory.

Indian scientists have developed a specific anti-forgery ink that can aid in the forging of papers such as passports, the packaging of counterfeit pharmaceuticals, and the counterfeiting of bank notes. When exposed to a specific frequency of light, this ink displays two colours.

It was created by scientists from the Council of Scientific and Industrial Research (CSIR) of National Physical Laboratory (NPL) in New Delhi and the Academy of Scientific and Innovative Research in Ghaziabad. The research was published in the journal Journal of Materials Chemistry-C.

Bank Note Press in Dewas has received a bi-luminescent security ink produced by the CSIR and National Physical Laboratory.

What is “Bi-Luminescent Security Ink”?

The “Bi-Luminescent Security Ink” produced by the CSIR-National Physical Laboratory has been proven to be similar to current standards. This new method can be used to check the legality of ID cards, passports, tamper-evident labels, and other government papers, among other things.

When exposed to different wavelengths of radiation, the bi-luminescent security ink lights in two colours: red and green. A 254nm light source makes it glow red, whereas a 365nm light source makes it shine green. The emission of red is due to fluorescence while green is due to phosphorescence phenomenon. The formulation is to be used to verify the authenticity of ID cards and other government papers, such as passports.

What is the Process of Making Ink?

The ink was created by combining two colours in a 3:1 ratio and heating them for three hours at 400oC. The ink comes in the form of a white powder. Then it was blended with PVC. The ink emits colour due to two types of luminescence: phosphorescence (green) and fluorescence (red).

Red and green pigments were created first. Hydrothermal technique is used to synthesise sodium yttrium fluorite doped with europium. Researchers combined strontium aluminium oxide with europium and dysprosium to create the green pigment.