TY  - JOUR
A1  - Miller, Franziska
A1  - Wintzheimer, Susanne
A1  - Prieschl, Johannes
A1  - Strauss, Volker
A1  - Mandel, Karl
T1  - A Supraparticle‐Based Five‐Level‐Identification Tag That Switches Information Upon Readout
T2  - Advanced Optical Materials
N2  - Product identification tags are of great importance in a globalized world with increasingly complex trading routes and networks. Beyond currently used coding strategies, such as QR codes, higher data density, flexible application as well as miniaturization and readout indication are longed for in the next generation of security tags. In this work, micron‐sized supraparticles (SPs) with encoded information (ID) are produced that not only exhibit multiple initially covert identification levels but are also irreversibly marked as “read” upon readout. To achieve this, lanthanide doped CaF\(_{2}\) nanoparticles are assembled in various quantity‐weighted ratios via spray‐drying in presence of a broad‐spectrum stealth fluorophore (StFl), yielding covert spectrally encoded ID‐SPs. Using these as pigments, QR codes, initially dominated by the green fluorescence of the StFl, could be generated. Upon thermal energy input, these particle‐based tags irreversibly switch to an activated state revealing not only multiple luminescent colors but also spectral IDs. This strategy provides the next generation of material‐based security tags with a high data density and security level that switch information upon readout and can be, therefore, used as seal of quality.
KW  - multilevel luminescence identification
KW  - rare earth doped nanoparticles
KW  - security tags
KW  - stealth fluorophores
KW  - supraparticles
Y1  - 2021
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/22446
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-224469
VL  - 9
IS  - 4
ER  -