Luminescent Carrageenan Hydrogels Containing Lanthanopolyoxometalates

Abstract

In this research, we investigated the use of lanthanopolyoxometalates {LnPOM, K9[Ln(W5O18)2], Ln = Eu, Tb} as luminophores in thermosensitive polysaccharides such as carrageenan hydrogels. We demonstrate that the LnPOM species still show the characteristic photoluminescence bands of the LnIII ion when incorporated in the gel matrix. Moreover, the strength of the carrageenan hydrogels increases by increasing the amount of LnPOM added because of the effect of K+ ions as cross‐linkers, but without compromising the photoluminescent behaviour. Nanoscale homogeneity is crucial regarding applications of hydrogels responsive to external stimuli. This research shows that the final LnPOM‐loaded hydrogels are homogeneous as a consequence of the diffusion behaviour of the luminophore species within the gel network. Therefore, we anticipate that the association of carrageenan hydrogels to luminescent lanthanopolyoxometalates might be of great relevance for optical devices and in particular for bioimaging techniques.

Sustainable Dual-Mode Smart Windows for Energy-Efficient Buildings

“…The CG 50 Er z membranes display UV/blue and NIR emission ascribed to the κ-Cg-based host and to the Er 3+ ( 4 I 15/2 → 4 I 13/2 transition), respectively, as illustrated in Figure a and b for a selected sample. The excitation spectrum monitored around the broad-band host emission peak (420 nm) reveals two main excitation paths at 280 and 360 nm (inset in Figure a).…”

Enhancing Hydrogels with Quantum Dots

“…These carrageenan-based hydrogels demonstrate enhanced photoluminescence properties, with the integration of lanthanopolyoxometalates improving both their luminescent characteristics and mechanical strength. This renders them promising candidates for applications in optical devices [25]. Expanding upon the capabilities of microfluidics, a novel approach employs a thermo-reversible gelling polymer to facilitate the sorting of DNA molecules.…”

“…Material innovation continues with enhancements in the mechanical and optical properties of hydrogels [25,45] and the development of smart materials for chemical and biological sensing [76]. The integration of quantum dots and nanomaterials into hydrogels enables precise detection of enzymes, pollutants, and metal ions [61,84,85], and hydrogels responsive to pH, temperature, and metal ions are tailored to diverse applications [62,72,86].…”

“…Tailored hydrogels are developed for specific functions, including ion sensing, catalysis, drug delivery, and photocatalytic hydrogen production, highlighting the focus on biocompatibility and biomimetics with materials like collagen and peptides for applications in drug delivery, tissue engineering, and high-load-bearing scenarios [3,5,9,12,[20][21][22][23]. The research extends into lanthanide-doped and luminescent hydrogels, driven by their potential in environmental sensing and medical imaging [24,25].…”

Raman and Fluorescence Imaging of Polyoxometalate Composite Agarose Films

“…Luminescent transparent composite films based on LnPOMs and filmogenic polysaccharides have been prepared by us, using pullulan and a water‐soluble cationic chitosan derivative . Thermosensitive polysaccharides such as carrageenan hydrogels have also been used in the preparation of LnPOM composites . Agarose films containing [Eu(SiW 10 MoO 39 ) 2 ] 13– and [Eu(W 5 O 18 ) 2 ] 9– (EuW10) were reported by Yao et al, The structural combination of a polymer hydrogel network with a nanoparticle or in this case with a nanosized POM anion, will provide a superior functionality to the composite material with potential applications in diverse fields .…”