This work presents a novel approach for detecting biogenic amine tyramine using a sensitive and disposable electrochemiluminescent sensor. The sensor is fabricated by modifying a screen-printed ...carbon electrode surface with two nanomaterials, α-Ge nanolayers and AuNP, which synergistically enhance the electrochemiluminescence response. The sensor was characterized using various techniques such as SEM-EDX, EIS, Raman, and AFM. The principle of the biosensor relays on the fact that tyramine molecule acts as an analyte and co-reactant, which interacts with the luminophore Ru(bpy)32+ on the sensor surface. The proposed sensor shows a linear response to tyramine concentration, with a detection limit of 2.28 µM. The sensor successfully detected tyramine in avocado samples, demonstrating its potential for practical applications.
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•Tyramine electrochemiluminescent-sensor.•α-Ge and AuNP enhance the electrochemiluminescence.•Tyramine as analyte and co-reactant simultaneously.
3D COF Nanoparticles
In article number 2306345, Carlos Franco, Salvador Pané, Josep Puigmartí‐Luis, and co‐workers present a water‐based nanoreactor technology that pioneers the creation of sub‐40 nm ...3D covalent organic framework (COF) nanoparticles under ambient conditions. This method not only improves the processability of 3D COFs but also unveils exciting possibilities in microrobotics. A notable achievement is the fabrication of the first COF‐based microrobots (COFBOTs).
We report herein an efficient, fast, and simple synthesis of an imine‐based covalent organic framework (COF) at room temperature (hereafter, RT‐COF‐1). RT‐COF‐1 shows a layered hexagonal structure ...exhibiting channels, is robust, and is porous to N2 and CO2. The room‐temperature synthesis has enabled us to fabricate and position low‐cost micro‐ and submicropatterns of RT‐COF‐1 on several surfaces, including solid SiO2 substrates and flexible acetate paper, by using lithographically controlled wetting and conventional ink‐jet printing.
Printed crystals: An efficient, fast and simple synthesis of an imine‐based porous covalent organic framework (COF) at room temperature is reported. The room‐temperature synthesis enables fabricating micro‐ and submicropatterns of this COF on a variety of surfaces by ink‐jet printing and wet lithographically techniques.
•Microfluidics can be used for up-scaled processing of covalent-organic frameworks.•Microfluidics offers an exquisite control over mixing regimes.•Mixing regimes can tailor the shape, morphology and ...surface integration of COFs.•Microfluidics can reveal morphogenesis of COFs via simulated microgravity.
Nearly twenty years since the discovery of covalent-organic frameworks (COFs), most of the research on these materials has been focused on the rational design of new structures. Recently, the quest for discovering the functionalities and potential applications of these crystalline materials has attracted the attention of many researchers. While the number of reports regarding these two aspects within the COF research area is continuously growing, in order to achieve their full potential, the processability aspect of COFs also needs to be addressed. In this review article, we examine the opportunities that flow-based technologies offer regarding (a) the continuous synthesis of COFs, and (b) the processing of these materials into functional surfaces and devices (e.g. thin films and 3D structures), both aspects being ultimately amenable to industrial scale up.
On page 6332, J. Gómez‐Herrero, F. Zamora, and co‐workers describe the isolation of antimonene, a new allotrope of antimony that consists of a single layer of atoms. They obtain antimonene flakes by ...the scotch tape method; these flakes are highly stable in ambient conditions and even when immersed in water. The 1.2 eV gap calculated in this study suggests potential applications in optoelectronics.
Functionalized with porphyrins: The interactions of metalloporphyrins with graphene oxide and pyridine‐substituted graphene oxide have been probed (see figure). The interactions elucidated offer ...unprecedented tools in the quest for functional nanostructured materials.
Abstract In this study, we present a novel approach for the synthesis of covalent organic frameworks (COFs) that overcomes the common limitations of non‐scalable solvothermal procedures. Our method ...allows for the room‐temperature and scalable synthesis of a highly fluorinated DFTAPB‐TFTA‐COF, which exhibits intrinsic hydrophobicity. We used DFT‐based calculations to elucidate the role of the fluorine atoms in enhancing the crystallinity of the material through corrugation effects, resulting in maximized interlayer interactions, as disclosed both from PXRD structural resolution and theoretical simulations. We further investigated the electrocatalytic properties of this material towards the oxygen reduction reaction (ORR). Our results show that the fluorinated COF produces hydrogen peroxide selectively with low overpotential (0.062 V) and high turnover frequency (0.0757 s −1 ) without the addition of any conductive additives. These values are among the best reported for non‐pyrolyzed and metal‐free electrocatalysts. Finally, we employed DFT‐based calculations to analyse the reaction mechanism, highlighting the crucial role of the fluorine atom in the active site assembly. Our findings shed light on the potential of fluorinated COFs as promising electrocatalysts for the ORR, as well as their potential applications in other fields.
The use of covalent organic frameworks (COFs) in practical applications demands shaping them into macroscopic objects, which remains challenging. Herein, we report a simple three‐step method to ...produce COF aerogels, based on sol‐gel transition, solvent‐exchange, and supercritical CO2 drying, in which 2D imine‐based COF sheets link together to form hierarchical porous structures. The resultant COF aerogel monoliths have extremely low densities (ca. 0.02 g cm−3), high porosity (total porosity values of ca. 99 %), and mechanically behave as elastic materials under a moderate strain (<25–35 %) but become plastic under greater strain. Moreover, these COF aerogels maintain the micro‐ and meso‐porosity of their constituent COFs, and show excellent absorption capacity (e.g. toluene uptake: 32 g g−1), with high removal efficiency (ca. 99 %). The same three‐step method can be used to create functional composites of these COF aerogels with nanomaterials.
A three‐step method produces COF aerogel monoliths, based on sol–gel transition, solvent‐exchange, and supercritical CO2 drying. 2D imine‐based COF sheets link together to form hierarchical porous structures. The aerogels have extremely low densities, high porosity, and mechanically behave as elastic or plastic materials under different strain. They show excellent absorption capacity with high removal efficiency.
Can controlled diffusion of reagents together with micro‐shielding features enable the regioselective localization of different chemical processes? In article number 1903172, Josep Puigmarti‐Luis and ...co‐workers present a method for the in‐situ fabrication of custom designed surface‐enhanced Raman spectroscopy (SERS) substrates as well as for the selective localization of multiple chemical reactions onto surfaces.
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