Water-sensitive multicolor luminescence in lanthanide-organic framework for anti-counterfeiting

Abstract

The development of high-level anti-counterfeiting techniques is of great significance in economics and security issues. However, intricate reading methods are required to obtain multi-level information stored in different colors, which greatly limits the application of anti-counterfeiting technology on solving real world problems. Herein, we realize multicolor information anti-counterfeiting under simply external stimulation by utilizing the functional groups and multiple emission centers of lanthanide metal organic framework (Ln-MOFs) to tune luminescence color. Water responsive multicolor luminescence represented by both the tunable color from red to blue within the visible region and high sensitive responsivity has been achieved, owing to the increased nonradiative decay pathways and enhanced Eu 3+ -to-ligand energy back transfer. Remarkably, information hidden in different colors needs to be read with a specific water content, which can be used as an encryption key to ensure the security of the information for high-level anti-counterfeiting.

Our journey of developing dual‐emitting metal‐organic framework‐based fluorescent sensors

“…v) MOFs with multiple emission centers should be developed for simultaneous detection of multiple targets. vi) The sensing mechanisms are still vague or assumed, the Eu(BDCÀ NH 2 ) THF 0.002 0-5 [47] Tb(BDCÀ NH 2 ) THF 0.001 0-5 [47] EuÀ MOFs/N,SÀ CDs ethanol 0.03 0.05-4 [48] EuÀ BDC,Tb-bipy@Fe 3 O 4 /SiO 2 hexane 0.03 wt % 0-10 wt % [49] R6G@Mn-sdc-2 ethanol 0.035 0-10 [50] Zn(hpi2cf)(DMF)(H 2 O) methanol < 0.05 0-1.30 [51] AEMOF-1' THF ethanol 0.05 0.05 0.05-5 0.05-3 [52] FS@ZIF- TbPDBA-8 dioxane NR 0-10 interaction between MOF hosts and targeted species remains to be further investigated. We believe that the concept, design, and construction method of dual-emitting MOFs will provide fruitful values for natural science and analytical techniques.…”

“…Recently, we reported a self-referenced and highly sensitive luminescent MOF sensor Ln(BDCÀ NH 2 ) (Ln 3 + = Eu 3 + , Tb 3 + ; H 2 BDCÀ NH 2 = 2-aminoterephthalic acid) for detection trace water in organic solvents. [47] Benefiting from the suitable solubility of Ln(BDCÀ NH 2 ) in water and hydrogen-bond interaction between -NH 2 group and water molecule, as-synthesized Ln(BDCÀ NH 2 ) exhibits gradually enhanced ligand-based luminescence and quenched lanthanide emission with increasing the water content in organic solvents such as THF, DMF, ethanol and acetone (Figure 10). The good linear correlation between luminescence intensity ratios of ligands and Eu 3 + /Tb 3 + ions and water content enables Ln(BDCÀ NH 2 ) to detect water in THF over a wide range from 0 to 5 vol % with an ultra-low LOD of 0.002 vol % for Eu(BDCÀ NH 2 ) and 0.001 vol % for Tb(BDCÀ NH 2 ).…”

“…The accurate and rapid quantification of water in organic solvents is of a great importance and has been received considerable attention in recent years because water is the most common impurity in organic solvents and is usually detrimental to many chemical and industrial production processes. Recently, we reported a self‐referenced and highly sensitive luminescent MOF sensor Ln(BDC−NH 2 ) (Ln 3+ =Eu 3+ , Tb 3+ ; H 2 BDC−NH 2 =2‐aminoterephthalic acid) for detection trace water in organic solvents [47] . Benefiting from the suitable solubility of Ln(BDC−NH 2 ) in water and hydrogen‐bond interaction between ‐NH 2 group and water molecule, as‐synthesized Ln(BDC−NH 2 ) exhibits gradually enhanced ligand‐based luminescence and quenched lanthanide emission with increasing the water content in organic solvents such as THF, DMF, ethanol and acetone (Figure 10).…”

Localized Nanopore Fabrication via Controlled Breakdown

“…Optical nanopores [ 96 ] can benefit from the high bandwidth of optical measurements, as well as the ease of monitoring optical signals at high throughput [ 22 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 146 , 147 , 148 ]. On the other hand, nanopore techniques can actively deliver target molecules into the optical sensing area instead of relying on diffusion or tethering [ 95 , 105 , 110 , 112 , 149 ].…”

Selective Ligand Sensitization of Lanthanide Nanoparticles for Multilevel Information Encryption with Excellent Durability

“…24−26 However, there have been rarely reported cases of lanthanide-based nanomaterials possessing stimuli-responsive features for optical information encryption. 20,27,28 Herein, we prepared lanthanide fluoride nanoparticles (Ln NPs) as invisible ink to produce encrypted patterns, which remained invisible under both UV illumination and daylight (Scheme 1).…”