Recently, the biomineralization of enzyme in metal−organic-framework (enzyme-MOF) composite have shown a great potential to increase enzymes stability without compromising their activity; hence, it is desirable for its applications in biosensing devices. Nonetheless, most of the enzyme-MOF research has been focusing on enzyme encapsulation in particle form, which limits its synthesis flexibility for practical applications because of its requirement for postsynthesis immobilization onto solid support. Therefore, to develop a diagnostic device out of the biomineralized enzyme, surface patterning and integration of microfluidic system offers many advantages. In this work, musselinspired polydopamine/polyethyleneimine (PDA/PEI) coating is employed to pattern enzyme-MOF in microfluidic channels and exploit the wettability gradient for "pumpless transportation" effect. As a proof of concept, we combine a cascade reaction of glucose oxidase (GOx) and horseradish peroxidase (HRP) enzymes to detect glucose into a patterned zeolitic imidazole framework-8 (ZIF-8) thin film on a flexible polymeric substrate. The results show that the ZIF-8/GOx&HRP in situ composites on PDA/PEI patterns have good acid and thermal stability compared with samples without ZIF-8. ZIF-8/GOx&HRP in situ shows high selectivity toward glucose, linear sensitivity of 0.00303 Abs/μM, and the limit of detection of 8 μM glucose concentration. An unexpected benefit of this approach is the ability of the ZIF-8 thin-film structure to provide a diffusion limiting effect for substrate influx, thus, producing high range of linear response range (8 μM to 5 mM of glucose). This work provides insights into the spatial location of the enzymes in MOF thin films and the potential of such patterning techniques for MOF-based biosensors using other types of biological elements such as antibodies and aptamers.
Biological ion channels feature angstrom‐scale asymmetrical cavity structures, which are the key to achieving highly efficient separation and sensing of alkali metal ions from aqueous resources. The clean energy future and lithium‐based energy storage systems heavily rely on highly efficient ionic separations. However, artificial recreation of such a sophisticated biostructure has been technically challenging. Here, a highly tunable design concept is introduced to fabricate monovalent ion‐selective membranes with asymmetric sub‐nanometer pores in which energy barriers are implanted. The energy barriers act against ionic movements, which hold the target ion while facilitating the transport of competing ions. The membrane consists of bilayer metal‐organic frameworks (MOF‐on‐MOF), possessing a 6 to 3.4‐angstrom passable cavity structure. The ionic current measurements exhibit an unprecedented ionic current rectification ratio of above 100 with exceptionally high selectivity ratios of 84 and 80 for K+/Li+ and Na+/ Li+, respectively (1.14 Li+ mol m−2 h−1). Furthermore, using quantum mechanics/molecular mechanics, it is shown that the combined effect of spatial hindrance and nucleophilic entrapment to induce energy surge baffles is responsible for the membrane's ultrahigh selectivity and ion rectification. This work demonstrates a striking advance in developing monovalent ion‐selective channels and has implications in sensing, energy storage, and separation technologies.
Purpose Despite the significant advances in modeling of biomechanical aspects of cell microenvironment, it remains a major challenge to precisely mimic the physiological condition of the particular cell niche. Here, the metal–organic frameworks (MOFs) have been introduced as a feasible platform for multifactorial control of cell-substrate interaction, given the wide range of physical and mechanical properties of MOF materials and their structural flexibility. Results In situ crystallization of zeolitic imidazolate framework-8 (ZIF-8) on the polydopamine (PDA)-modified membrane significantly raised surface energy, wettability, roughness, and stiffness of the substrate. This modulation led to an almost twofold increment in the primary attachment of dental pulp stem cells (DPSCs) compare to conventional plastic culture dishes. The findings indicate that polypropylene (PP) membrane modified by PDA/ZIF-8 coating effectively supports the growth and proliferation of DPSCs at a substantial rate. Further analysis also displayed the exaggerated multilineage differentiation of DPSCs with amplified level of autocrine cell fate determination signals, like BSP1, BMP2, PPARG, FABP4, ACAN , and COL2A . Notably, osteogenic markers were dramatically overexpressed (more than 100-folds rather than tissue culture plate) in response to biomechanical characteristics of the ZIF-8 layer. Conclusion Hence, surface modification of cell culture platforms with MOF nanostructures proposed as a powerful nanomedical approach for selectively guiding stem cells for tissue regeneration. In particular, PP/PDA/ZIF-8 membrane presented ideal characteristics for using as a barrier membrane for guided bone regeneration (GBR) in periodontal tissue engineering.
Clinacanthus nutans is a well recognized medicinal herb for its high phytochemical contents. Several aspects may contribute to the phytochemical contents, and thus determine the quality and efficacy of an herb. An experiment was conducted using a completely randomized design (CRD) with five replications, in a factorial arrangement of treatments. including two plant parts harvested at two different stages such as young leaves, young stems, matured leaves and matured stems, and four different storage durations such as 1, 2, 3 and 4 days. The study was aimed at determining how storage duration affects selected phytochemical contents of different plant parts of C. nutans at different harvesting stages. Total phytochemical content, total flavonoids content and DPPH radical scavenging activities are higher in young plants than in old plants, moreover, all those compounds are higher in leaves than in stems, and decrease gradually due to storage. Phytochemical, ascorbic acid and chlorophyll content of C. nutans differ among different plant parts and change due to storage. In general, young plant parts contain higher amount of phytochemicals, ascorbic acid and chlorophyll compared with matured parts confirming that phytochemicals content of C. nutans decreases when plants tend to maturity. Prolonged storage reduces phytochemical, ascorbic acid and chlorophyll content of C. nutans,which demands fresh use of this medicinal herb to avoid phytochemical losses. Further research focusing on the proper storage is necessary to minimize phytochemicals losses of C. nutans.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.