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Tryptophan, an essential amino acid playing a pivotal role in various biological processes, stands as a focal point in our investigation. In this study, we introduce a groundbreaking electrochemical sensor that integrates a nanocomposite comprising carbon black (CB) and zinc oxide nanoparticles (ZnO-NPs) for the selective detection of L-tryptophan (Trp). The synthesis of ZnO-NPs, accomplished through the sol-gel technique, was meticulously characterized using XRD, FTIR, and UV-visible methods to unveil their structural and optical properties. The construction of the sensing electrode involved the deposition of a CB/ZnO-NP nanocomposite onto a glassy carbon electrode (GCE) utilizing the drop-coating method. Rigorous evaluation and analysis of the modified glassy carbon electrode were carried out through scanning electron microscopy (SEM), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The resulting CB/ZnO-NPs/GCE electrode exhibited an augmented surface area and outstanding electrocatalytic activity. Significantly, the CB/ZnO-NP sensor displayed remarkable analytical performance for tryptophan detection over an extensive concentration range from 0.01 to 100 µmol.L−1, featuring a low detection limit of 0.017 µmol.L−1. Moreover, the proposed electrochemical sensor exhibited notable selectivity, specifically targeting tryptophan, emphasizing its potential for diverse analytical applications. This work not only expands our understanding of tryptophan detection but also offers a highly sensitive and selective tool with broad applications in biomedical and environmental fields, underscoring the significance of this innovative sensor in advancing analytical methodologies. [ABSTRACT FROM AUTHOR]

3D printing plays an important role in Industry 4.0 and has versatility to use different materials, including thermoplastic polymers. Polylactic acid (PLA), a bio‐based biodegradable polymer, is used as a potential replacement for petroleum‐based polymers in several applications, and is one of the most popular polymers used in 3D printing. Inorganic/organic nanoparticles can be incorporated in polymers to improve various properties such as thermal, mechanical, and tribological. This work investigates the effect of adding carbon black (CB) and alumina (ALM) nanofillers on the thermal, mechanical, and tribological properties of 3D printed PLA nanocomposites for tribological applications. Both nanofillers promoted progressive enhancement of thermal stability according to TGA. The improvement in the interaction between nanofillers and PLA matrix is revealed by an increase in viscosity of the nanocomposites. The nanocomposites containing 25%wt ALM and 75wt% CB presented better mechanical and wear properties, suggesting synergism between nanofillers and that CB may act as a compatibilizer between PLA and ALM. These results enable selecting the most suitable composition of nanofillers to be added to PLA to create filaments with better tribological properties. [ABSTRACT FROM AUTHOR]

Abstract: Polypropylene/carbon black (PP/CB) nanocomposites were prepared by melt compounding to investigate the effect of nanofiller loadings on the thermal and flammability properties of PP. The obtained nanocomposites displayed not only dramatically enhanced thermal stability both under nitrogen and in air, but also improved flame retardancy to some extent. Moreover, the higher the loading level of CB, the better was the improved effect. This enhanced mechanism was attributed mainly to trapping of peroxy radicals by CB nanoparticles at elevated temperature to form a gelled-ball crosslinked network, which act as a barrier to both heat and mass transfer. The thermal-oxidation cross-linking reaction was supported by the results of rheological properties, gel measurements and FTIR analysis. [Copyright &y& Elsevier]