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Carbon-based functional nanocomposites have emerged as potent antimicrobial agents and can be exploited as a viable option to overcome antibiotic resistance of bacterial strains. In the present study, graphitic carbon nitride nanosheets are prepared by controlled calcination of urea. Spectroscopic measurements show that the nanosheets consist of abundant carbonyl groups and exhibit apparent photocatalytic activity under UV photoirradiation towards the selective production of singlet oxygen. Therefore, the nanosheets can effectively damage the bacterial cell membranes and inhibit the growth of bacterial cells, such as Gram-negative Escherichia coli, as confirmed in photodynamic, fluorescence microscopy, and scanning electron microscopy measurements. The results from this research highlight the unique potential of carbon nitride derivatives as potent antimicrobial agents. 

Synergetic interactions between ruthenium and molybdenum oxide weaken H adsorption on ruthenium active sites and hence enhance the electrocatalytic activity towards hydrogen evolution reaction. 

Abstract Antibiotic‐resistant bacterial strains are an ever‐present hurdle for human health. A route to overcoming this threat is the development of effective antimicrobial agents based on carbon‐supported nanocomposites. In this study, carbon dots (CD) are synthesized by a facile hydrothermal treatment of ethylenediaminetetraacetic acid and melamine and further functionalized with nickel hydroxide colloids. Whereas CD alone exhibits virtually no antimicrobial activity under photoirradiation at 365 nm againstEscherichia coliin comparison to the blank control, the performance is markedly enhanced with the Ni(OH)₂‐CD nanocomposites, with the lag time prolonged from 7 to 15 h and growth rate reduced by ca. 15%. This is ascribed to the Ni(OH)₂colloids that facilitate the separation of photogenerated electron‐hole pairs and ensuing production of superoxide radicals, as confirmed by photoluminescence and electron paramagnetic resonance measurements, which induce oxidative stress and damage to the bacterial cell membranes, thereby leading to effective bactericidal activity. Consistent results are obtained in live/dead assays. Results from this work highlight the unique potential of carbon‐based composites in the development of next‐generation antimicrobial agents. 

Sensitive in-cell distance measurements in proteins using pulsed-Electron Spin Resonance (ESR) require reduction-resistant and cleavage-resistant spin-labels. Among the reduction-resistant moieties, the hydrophilic trityl core known as OX063 is promising due to its long phase-memory relaxation time (T_m). This property leads to a sufficiently intense ESR signal for reliable distance measurements. Furthermore, the T_m of OX063 remains sufficiently long at higher temperatures, opening the possibility for measurements at temperatures above 50 K. In this work, we synthesized deuterated OX063 with a maleimide linker (mOX063-d24). We show that the combination of the hydrophilicity of the label and the maleimide linker enables high protein labeling that is cleavage-resistant in-cells. Distance measurements performed at 150 K using this label are more sensitive than the measurements at 80 K. The sensitivity gain is due to the significantly short longitudinal relaxation time (T_1) at higher temperatures, which enables more data collection per unit of time. In addition to in vitro experiments, we perform distance measurements in Xenopus laevis oocytes. Interestingly, the T_m of mOX063-d24 is sufficiently long even in the crowded environment of the cell, leading to signals of appreciable intensity. Overall, mOX063-d24 provides highly sensitive distance measurements both in vitro and in-cells.