Upcycling fish scales for water pollution control and encryption – NUS News

The fluorescent properties of the heat-treated fish scales under different types of light can also be harnessed for steganographic purposes. Scales can be heated in bulk on a hotplate and arranged to convey a message, or laser-engraved with text and images on a microscopic scale. These hidden messages can be revealed under UV light. Heat-treated fish scales which have adsorbed Rhodamine B also glow orange under green light excitation, compared to the same heat-treated fish scales without Rhodamine B that display a very dim blue fluorescence under the same light. This presents another option for steganographic pattern design.