Size Refinement of Copper Nanoparticles: A Perspective from Electrochemical Nucleation and Growth Mechanism

Construction of a self-reporting molecularly-imprinted electrochemical sensor based on CuHCF modified by rGNR-rGO for the detection of zearalenone

A self-reporting molecularly-imprinted electrochemical sensor is prepared for the detection of Zearalenone (ZEA). Firstly, the reduced graphene nanoribbons and reduced graphene oxide (rGNR-rGO) were simultaneously modified onto a glassy carbon electrode (GCE) to improve the sensor's sensitivity. After electrodepositing copper nanoparticles onto the rGNR-rGO/GCE, cyclic voltammetry scanning was performed in potassium ferrocyanide solution, and copper hexacyanoferrate (CuHCF) was deposited onto rGNR-rGO/GCE to further improve the sensor's sensitivity while giving it self-reporting capability. Then, molecularly-imprinted polymer films were prepared on the CuHCF/rGNR-rGO/GCE to ensure the selectivity of the sensor. It is found that the linear range of ZEA detection by the constructed sensor is 0.25-500 ng·mL -1, with a detection limit of 0.09 ng·mL -1. This sensor shows the merits of good selectivity, high sensitivity and accurate detection, providing a great possibility for the precise detection of low concentration ZEA in food.

Green approaches for the synthesis of metal and metal oxide nanoparticles using microbial and plant extracts

Green synthesis approaches are gaining significance as promising routes for the sustainable preparation of nanoparticles, offering reduced toxicity towards living organisms and the environment. Nanomaterials produced by green synthesis approaches can offer additional benefits, including reduced energy inputs and lower production costs than traditional synthesis, which bodes well for commercial-scale production. The biomolecules and phytochemicals extracted from microbes and plants, respectively, are active compounds that function as reducing and stabilizing agents for the green synthesis of nanoparticles. Microorganisms, such as bacteria, yeasts, fungi, and algae, have been used in nanomaterials' biological synthesis for some time. Furthermore, the use of plants or plant extracts for metal and metal-based hybrid nanoparticle synthesis represents a novel green synthesis approach that has attracted significant research interest. This review discusses various biosynthesis approaches via microbes and plants for the green preparation of metal and metal oxide nanoparticles and provides insights into the molecular aspects of the synthesis mechanisms and biomedical applications. The use of agriculture waste as a potential bioresource for nanoparticle synthesis and biomedical applications of biosynthesized nanoparticles is also discussed.

Green approaches for the synthesis of metal and metal oxide nanoparticles using microbial and plant extracts

Green synthesis approaches are gaining significance as promising routes for the sustainable preparation of nanoparticles, offering reduced toxicity towards living organisms and the environment.

A quantitative model to understand the microflow-controlled sintering mechanism of metal particles at nanometer to micron scale

In this paper, the particle size effect on the sintering behaviors of Cu particles at nanometer to micron scale is explored. The results show that micron-sized particles could form obvious sintering necks at a low temperature of 260 °C, exhibiting a shear strength as high as 64 MPa. A power relation ofx ∝ a^0.8between sintering neck radius (x) and particle radius (a) is discovered, and a sintering model with a quantitative relational expression of (x/a)⁵ = 160γδDt/3akTis proposed by considering the surface tension driven microflow process between adjacent particles to predict the growth of sintering necks. It is concluded that the sintering process of particles at nanometer to micron scale is controlled by microflow mechanism instead of diffusion mechanism. Our proposed model provides a new theoretical basis for understanding the kinetic growth mechanism of sintering necks of metal particles.