Lanthanide-Directed Luminescent “Soft” Coordination Polymer Gels: White Light Emission, Anticounterfeiting, and Thin-Film-Based Sensing

Abstract

Stimuli-responsive light-emitting materials are of great interest owing to their potential use in encryption and multilevel security. In this context, herein, the synthesis of light-emitting multifunctional coordination polymer gels (CPGs) was accomplished by the self-assembly of europium and terbium acetate with a bifunctional (amide/carboxylic acid) gelator. The assynthesized luminescent CPGs are stable up to 300 °C. The FESEM micrograph exhibits pebble-like morphology, and the TEM images reveal a sheet-like structure which is grown on top of each other. The optical properties of the as-synthesized CPGs are readily tuneable over a broad spectrum, including white-light emission, simply by modulating the europium and terbium ion stoichiometry. The as-synthesized luminescent materials have the potential to be used as invisible security inks for high-security information encoding. Additionally, water-resistant luminescent thin films were fabricated by incorporating Eu@BTT or Tb@BTT (BTT: 5,5′,5″-((benzene-1,3,5tricarbonyl)tris(azanediyl))triisophthalic acid) into the poly(methyl methacrylate) (PMMA) polymer matrix for the naked eye test of nitro-explosive compounds (2,4,6-trinitrophenol and nitrophenol). The sensing mechanism is proposed based on the DFT and time-resolved photoluminescence studies.

A recyclable MOF@polymer thin film composite for nanomolar on-site fluorometric detection of heavy metal ion and anti-histamine drug and efficient heterogeneous catalysis of Friedel–Crafts alkylation

“…According to various reported works, several phenomena might cause the fluorescence quenching, including breaking of the MOF structure, ground-state complexation, the inner filter effect (IFE), Förster resonance energy transfer (FRET), photoinduced electron transfer (PET), etc . 10,36–38…”

Naphthalimide functionalized metal–organic framework for rapid and nanomolar level detection of hydrazine and anti-hypertensive drug nicardipine

“…15 Many classes of fluorometric sensors materials have been used for the sensing of hazardous materials and drugs including quantum dots, graphene oxide-based materials, carbon nanotubes, metallogel, organic probes, and metal–organic frameworks (MOFs). 17–21 Among them, MOFs nowadays have become a promising class of sensors for detecting several important analytes due to their porous nature with very high surface area, high stability and tuneable functionality. 22,23…”

MOF-Fabric Composites Based on a Multi-Functional MOF as Luminescent Sensors for a Neurotransmitter and an Anti-Cancer Drug

“…To date, the quantitative determination of adrenaline and 6-MP has been reported using a variety of techniques, including electrochemical, liquid chromatography, capillary electrophoresis, and chemiluminescence. − However, the majority of these approaches are constrained by their laborious operation, high cost, and even reliance on pre-treatment. − On the other hand, fluorescence-based detection methods are widely used because they satisfy key requirements for practical sensors, including high selectivity, sensitivity, short response time, real-time sensing capability, and cost-effectiveness. , …”