Recent Advances of Enzyme-Free Electrochemical Sensors for Flexible Electronics in the Detection of Organophosphorus Compounds: A Review.

Emerging materials integrated into high performance flexible electronics to detect environmental contaminants have received extensive attention worldwide. The accurate detection of widespread organophosphorus (OP) compounds in the environment is crucial due to their high toxicity even at low concentrations, which leads to acute health concerns. Therefore, developing rapid, highly sensitive, reliable, and facile analytical sensing techniques is necessary to monitor environmental, ecological, and food safety risks. Although enzyme-based sensors have better sensitivity, their practical usage is hindered due to their low specificity and stability. Therefore, among various detection methods of OP compounds, this review article focuses on the progress made in the development of enzyme-free electrochemical sensors as an effective nostrum. Further, the novel materials used in these sensors and their properties, synthesis methodologies, sensing strategies, analytical methods, detection limits, and stability are discussed. Finally, this article summarizes potential avenues for future prospective electrochemical sensors and the current challenges of enhancing the performance, stability, and shelf life.

Room-Temperature Synthesis of Thioether-Stabilized Ruthenium Nanocubes and Their Optical Properties.

Controlling the nucleation and growth processes for nanoparticle synthesis allows the development of well-defined structures that offer unique chemical and physical properties. Here, we report a wet chemical reduction method for synthesizing ruthenium nanocubes (Ru NCs) that display plasmonic properties at room temperature (RT). The growth of the particles to form nanostructured cubes was established by varying the carbon chain length of the thioether stabilizing ligands and the reaction time to produce stable and controlled growth. In this study, we found that the longer the thioether chain length, the less isotropic the shape of the particles. Short chain lengths of thioethers (ethyl sulfide and butyl sulfide) produced spherical nanoparticles, whereas longer chain lengths (hexyl sulfide and octyl sulfide) produced cubic nanoparticles. In addition, parameters such as the ligand to precursor ratio also played an important role in the homogeneity of the nanocubes. The Ru NCs were characterized by UV-visible absorbance spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), which supported a face-centered cubic (fcc) structure. Moreover, to demonstrate catalytic efficiency, we studied their ability to reduce benzaldehyde to benzyl alcohol, and the Ru NCs demonstrated an overall 78% efficiency at room temperature.