Search

Cephalopods use stretchy skin and dynamic color-tuning organs for visual communication and camouflage. Inspired by these natural mechanisms, a fluorescent biomaterial for deformation-induced illumination and optical communication is proposed. This is the first report of 3D printed soft biomaterials infused with carbon dots hydrothermally derived from chitosan and benzalkonium chloride. These biomaterials exhibit a comprehensive array of properties, including significant uniaxial stretching, near-instantaneous response to tactile stimuli and pH, UV resistance, antibacterial, antioxidant, noncytotoxicity, and highlighting their potential as mechano-optical materials for biomedical applications. The hydrogel's durability is evaluated by cyclic stretching, folding, rolling, and twisting tests to ensure its integrity and good signal-to-noise ratio. The diffusion mechanism is determined by water imbibition kinetics, network parameters, and time-dependent breathing. Overcoming the common limitations of short lifespans and complex manufacturing processes in existing soft hybrids, this work demonstrates a straightforward method to produce durable, energy-independent, mechano-optical hydrogel. Combined with investigations, molecular dynamic modeling is used to understand the interactions of hydrogel components., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

This study unveils the electrochemically-enhanced nanozymatic activity exhibited by borophene during the reaction of 3,3',5,5'-tetramethylbenzidine (TMB) and H 2 O 2 . Herein, the surface of the pristine borophene was first modified with the addition of thiocyanate groups to improve hydroxyl radical (•OH) scavenging activity. Then, the oxidation reaction of TMB was accelerated under applied electrochemical potential. Both factors significantly improved the detection limit and drastically decreased the detection time. DPPH testing revealed that the radical scavenging nature of borophene was more than 70%, boosting its catalytic activity. In the presence of H 2 O 2 , borophene catalyzed the oxidation of TMB and produced a blue-colored solution that was linearly correlated with the concentration of H 2 O 2 and allowed for the detection of H 2 O 2 up to 38 nM. The present finding was further extended to nanozymatic detection of tetracyclines (TCs) using a target-specific aptamer, and the results were colorimetrically quantifiable up to 1 μM with a LOD value of 150 nM. Moreover, transferring the principles of the discussed detection method to form a portable and disposable paper-based system enabled the quantification of TCs up to 0.2 μM. All the sensing experiments in this study indicate that the nanozymatic activity of borophene has significantly improved under electrochemical potential compared to conventional nanozyme-based colorimetric detection. Hence, the present discovery of electrochemically-enhanced nanozymatic activity would be promising for various sensitive and time-dependent colorimetric sensor development initiatives in the future., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Hospital-acquired (nosocomial) infections account for the majority of adverse health effects during care delivery, placing an immense financial strain on healthcare systems around the world. For the first time, the present article provides evidence of a straightforward pollution-free technique to fabricate a heteroatom-doped carbon dot immobilized fluorescent biopolymer composite for the development of functional textiles with antioxidant and antimicrobial properties. A simple, facile, and eco-friendly approach was devised to prepare heteroatom-doped carbon dots from waste green tea and a biopolymer. The carbon dots showed an excitation-dependent emission behavior, and the XPS data unveiled that they are co-doped with nitrogen and sulfur. A facile physical compounding strategy was adopted to fabricate a carbon dot reinforced biopolymeric composite followed by immobilization onto the textile. The composite textiles revealed excellent antioxidant activity, determined by 1,1-diphenyl-2-picrylhydrazyl (>80%) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid assays (>90%). The results of the disc diffusion assay indicated that the composite textiles substantially inhibited the growth of both tested bacteria Escherichia coli and Bacillus subtilis with increasing coating cycles. The time-dependent antibacterial experiments revealed that the nanocomposite can inhibit significant bacterial growth within a few hours. The present study could open up the possibility for the commercialization of inexpensive smart textile substrates for the prevention of microbial contamination used for the medical and healthcare field.

Thiocyanate (SCN - ) concentration monitoring in food is important to ensure the health and safety of the consumers.A colorimetric detection of thiocyanate (SCN - ) based on the nanozymatic activity of gold nanoparticle-graphene quantum dots (GQDs-Au NPs) hybrids in the presence of 3,3',5,5'-tetramethylbenzidine (TMB) and H 2 O 2 has been proposed. Here, a new synthesis method of GQDs directly from graphite was introduced. Transmission electron microscopy (TEM) images revealed that the size of the GQDs was 3-5 nm, and the emission peak appeared at 450 nm. As-synthesized GQDs was utilized to produce GQDs-Au NPs hybrids without additional chemicals. However, the presence of SCN - inhibits the growth of Au NPs, the resulting Au NPs are smaller in size. Moreover, SCN - group is well-known for hydroxyl radical (OH) scavenging activity that could oxidize TMB. Both effects boosted the nanozymatic activity of GQDs-Au NPs to detect SCN - under optimized conditions with a limit of detection (LOD) of 3 nM. Present study also validates the methodology to detect SCN - in raw milk., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The concentration of thiocyanate (SCN - ) in bodily fluids is a good indicator of potential and severe health issues such as nasal bleeding, goiters, vertigo, unconsciousness, several inflammatory diseases, and cystic fibrosis. Herein, a visual SCN - sensing method has been developed using the enzyme-like nature of positively charged gold quantum dots (Au QDs) mixed with 3,3',5,5'- tetramethylbenzidine (TMB) and hydrogen peroxide (H 2 O 2) . This research also reports a new method of synthesizing positively charged Au QDs directly from gold nanoparticles through a hydrothermal process. Microscopic imaging has showed that the Au QDs were 3-5 nm in size, and the emission wavelength was at 438 nm. Au QDs did not display any enzyme-like nature while mixed up with TMB and H 2 O 2 . However, the nanozymatic activity of Au QDs appeared when SCN - was included, leading to a very low detection limit (LOD) of 8 nM and 99-105% recovery in complex media. The steady-state kinetic reaction of Au QDs showed that Au QDs had a lower Michaelis-Menten constant ( Km ) toward H 2 O 2 and TMB, which indicates that the Au QDs had a higher affinity for H 2 O 2 and TMB than horseradish peroxidase (HRP). A mechanism study has revealed that the scavenging ability of hydroxyl (•OH) radicals by the SCN - group plays an important role in enhancing the sensitivity in this study. The proposed nanozymatic "Off-On" SCN - sensor was also successfully validated in commercial milk samples.