Institute of Inorganic Chemistry, Department of Chemistry and Applied Bioscience, ETH Zürich, Zürich, Switzerland.
Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
Nat Commun. 2021 Feb 12;12(1):981. doi: 10.1038/s41467-021-21214-3.
Traditional fluorescence-based tags, used for anticounterfeiting, rely on primitive pattern matching and visual identification; additional covert security features such as fluorescent lifetime or pattern masking are advantageous if fraud is to be deterred. Herein, we present an electrohydrodynamically printed unicolour multi-fluorescent-lifetime security tag system composed of lifetime-tunable lead-halide perovskite nanocrystals that can be deciphered with both existing time-correlated single-photon counting fluorescence-lifetime imaging microscopy and a novel time-of-flight prototype. We find that unicolour or matching emission wavelength materials can be prepared through cation-engineering with the partial substitution of formamidinium for ethylenediammonium to generate "hollow" formamidinium lead bromide perovskite nanocrystals; these materials can be successfully printed into fluorescence-lifetime-encoded-quick-read tags that are protected from conventional readers. Furthermore, we also demonstrate that a portable, cost-effective time-of-flight fluorescence-lifetime imaging prototype can also decipher these codes. A single comprehensive approach combining these innovations may be eventually deployed to protect both producers and consumers.
传统的荧光标记物用于防伪，依赖于原始的图案匹配和视觉识别；如果要防止欺诈，额外的隐蔽安全特征，如荧光寿命或图案掩蔽是有利的。在此，我们展示了一种由寿命可调的卤化铅钙钛矿纳米晶体组成的电动力学打印的单一多荧光寿命安全标记系统，该系统可以通过现有的时间相关单光子计数荧光寿命成像显微镜和新型飞行时间原型进行解码。我们发现，通过阳离子工程，可以用甲脒部分取代乙二胺来制备具有单一或匹配发射波长的材料，从而生成“空心”甲脒铅溴钙钛矿纳米晶体；这些材料可以成功地打印成具有荧光寿命编码的快速读取标签，以防止常规读取器读取。此外，我们还证明，一种便携式、具有成本效益的飞行时间荧光寿命成像原型也可以破译这些代码。这些创新的综合应用可能最终被用于保护生产者和消费者。
