In the information age, it is important to protect the security and integrity of the information. As a result, the fluorescent ink as an antifake technology and the fingermark as an information carrier have aroused great interest. In this work, highly water‐soluble lanthanide (Ln³⁺)‐doped tetragonal phase (t‐) LaVO₄ nanoparticles (NPs) are successfully obtained via a simple, fast, and green microwave‐assisted hydrothermal method. The average size of t‐LaVO₄ NPs is about 43 nm. The aqueous solutions of Ln³⁺‐doped t‐LaVO₄ exhibit excellent fluorescence properties under ultraviolet light (UV) excitation (t‐LaVO₄:10%Eu is bright red and t‐LaVO₄:0.5%Dy is close to white). Some superb antifake fluorescent patterns are printed using Ln³⁺‐doped t‐LaVO₄ aqueous solution as ink, which indicates the as‐prepared Ln³⁺‐doped t‐LaVO₄ NPs as fluorescent ink can meet the various antifake requirements. Notably, the designed convenient antifake fluorescent codes with improved security could be directly scanned and decoded by a smart phone. What's more, the as‐prepared NPs can be used for the development of latent fingermark on various substrates and the second‐level detail information can be clearly obtained from the magnification of a fingermark. These results indicate that the as‐prepared Ln³⁺‐doped t‐LaVO₄ fluorescent NPs have great potential in security application.

中文翻译：

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轻松合成高水溶性镧系元素掺杂的t-LaVO4 NP用于防伪油墨和潜在指纹检测

在信息时代，重要的是保护信息的安全性和完整性。结果，引起人们极大兴趣的是作为防伪技术的荧光墨和作为信息载体的指印。在这项工作中，通过简单，快速且绿色的微波辅助水热方法成功获得了高度水溶性的镧系元素（Ln ³⁺）掺杂的四方相（t）LaVO ₄纳米颗粒（NP）。t-LaVO ₄ NP的平均大小约为43 nm。掺Ln ^3+的t-LaVO ₄的水溶液在紫外线（UV）激发下显示出优异的荧光特性（t-LaVO ₄：10％Eu是亮红色而t-LaVO ₄：0.5％Dy接近白色）。使用掺Ln ^3+的t-LaVO ₄水溶液作为墨水可以印刷一些出色的防伪荧光图案，这表明所制备的掺Ln ^3+的t-LaVO ₄ NP可以作为荧光墨水满足各种防伪要求。值得注意的是，可以通过智能电话直接扫描和解码设计的，具有提高的安全性的方便的防伪荧光代码。此外，准备好的NP可用于在各种基材上形成潜在的指印，并且可以通过放大指印清楚地获得第二级详细信息。这些结果表明，制备的Ln ³⁺掺杂的t-LaVO ₄ 荧光NP在安全应用中具有巨大的潜力。