Multi-Responsive Lanthanide-Based Hydrogel with Encryption, Naked Eye Sensing, Shape Memory, Self-Healing, and Antibacterial Activity

Abstract

In this work, we reported a multi-responsive luminescent hydrogel with properties of encryption, naked eye sensing of glucose, shape memory, self-healing, and antibacterial activity. The hydrogel (GA/CCS/DNSA/Eu3+) was obtained by mixing phenylboronic acid-modified gelatin (GA-DBA), catechol-modified carboxymethyl chitosan (CCS-PCA), 3,5-dinitrosalicylic acid (DNSA), and Eu3+ ions through a facile heating–cooling process. The resultant hydrogel exhibits reversible luminescence and color and phase changes in response to temperature, acid/base, salt, and redox stimuli. Based on the multiple responsiveness, information encryption and decryption, naked eye sensing of glucose, remarkable shape memory, and enhanced mechanical properties of the as-prepared hydrogel were realized. In addition, the self-healing capacity was also achieved due to the dynamic bonds in GA/CCS/DNSA/Eu3+ hydrogels. Specifically, the GA/CCS/DNSA/Eu3+ hydrogels possess antibacterial activity owing to the bacteriostasis of the CCS-PCA and DNSA/Eu3+ complex. Thus, GA/CCS/DNSA/Eu3+ hydrogels have potential applications in the fields of anticounterfeiting, wearable devices, biomedicine, sensing, etc.

Reversible data encryption–decryption using a pH stimuli-responsive hydrogel

“…To this end, recently, stimuli-responsive materials have received tremendous attention and have been considered as promising mediums for data security applications [12][13][14][15][16][17][18][19] . Exploiting the unique reactive properties of these smart materials, various data encryption platforms have been designed employing carbon dots composite 20 , mechanochromic hydrogel 21 and luminescent hydrogel 22 , etc.…”

Enrichment of Luminescence via Incorporation of Fluxes in La2Zr2O7:Tb3+ Nanophosphors: One Material, Many Possibilities-Latent Fingerprint Visualization, Anti- counterfeiting, Luminescent Flexible Films

“…They can be extensively used in various applications, such as optoelectronics devices, eld-effect transistors, detectors, medical diagnosis, bio-imaging, etc. [112][113][114]. Hence, luminescent gels have been paid much attention due to their outstanding biocompatibility and viscoelastic properties [115].…”

Advanced Functional Hydrogel Biomaterials Based on Dynamic B–O Bonds and Polysaccharide Building Blocks

“…124 For instance, a hydrogel with triple shape memory properties was obtained by combining the formation of reversible Schiff base bonds between the amino groups of CS and aldehyde groups of oxidized dextran, which was applied to memorize temporary shapes, with the chelation effect of various metal cations which fixed other temporary shapes. 125 A great example of the immense possibilities that combining natural polymers with dynamic covalent chemistry offer is found in the work recently published by Zhou et al 126 They reported a multi-responsive luminescent hydrogel prepared by mixing phenylboronic acidmodified gelatin, catechol-modified carboxymethyl chitosan, 3,5-dinitrosalicylic acid, and Eu 3+…”