Disentangling Competitive and Synergistic Chemical Reactivities During the Seeded Growth of High-Entropy Alloys on High-Entropy Metal Sulfide Nanoparticles.

The seeded growth of one type of nanoparticle on the surface of another is foundational to synthesizing many multifunctional nanostructures. High-entropy nanoparticles that randomly incorporate five or more elements offer enhanced properties due to synergistic interactions. Incorporating high-entropy nanoparticles into seeded growth platforms is essential for merging their unique properties with the functional enhancements that arise from particle-particle interactions.

Colloidal Nanoparticles of High Entropy Materials: Capabilities, Challenges, and Opportunities in Synthesis and Characterization.

Materials referred to as "high entropy" contain a large number of elements randomly distributed on the lattice sites of a crystalline solid, such that a high configurational entropy is presumed to contribute significantly to their formation and stability. High temperatures are typically required to achieve entropy stabilization, which can make it challenging to synthesize colloidal nanoparticles of high entropy materials. Nonetheless, strategies are emerging for the synthesis of colloidal high entropy nanoparticles, which are of interest for their synergistic properties and unique catalytic functions that arise from the large number of constituent elements and their interactions.

Temporal Evolution of Morphology, Composition, and Structure in the Formation of Colloidal High-Entropy Intermetallic Nanoparticles.

Morphology-controlled nanoparticles of high entropy intermetallic compounds are quickly becoming high-value targets for catalysis. Their ordered structures with multiple distinct crystallographic sites, coupled with the "cocktail effect" that emerges from randomly mixing a large number of elements, yield catalytic active sites capable of achieving advanced catalytic functions. Despite this growing interest, little is known about the pathways by which high entropy intermetallic nanoparticles form and grow in solution.

Chemical Insights into the Formation of Colloidal High Entropy Alloy Nanoparticles.

Nanoparticles of high entropy alloys (HEAs) have distinct properties that result from their high surface-to-volume ratios coupled with synergistic interactions among their five or more constituent elements, which are randomly distributed throughout a crystalline lattice. Methods to synthesize HEA nanoparticles are emerging, including solution approaches that yield colloidal products. However, the complex multielement compositions of HEA nanoparticles make it challenging to identify and understand their reaction chemistry and the pathways by which they form, which hinders their rational synthesis.

Surface Engineered PLGA Nanoparticle for Threshold Responsive Glucose Monitoring and "Self-Programmed" Insulin Delivery.

We have developed a reversible, biocompatible, "self-programmed" PLGA [poly(lactic--glycolic acid)] nanoparticle-based optical biosensor capable of sensing and continuous monitoring of glucose above the physiologically relevant threshold value (100-125 mg/dL) as well as "on-demand" insulin delivery via an "On-Off" technique. We have carefully surface engineered the PLGA nanoparticle using amino dextran-fluorescein (A-DexFl) and amino-phenyl boronic acid (A-PBA) to exploit the binding affinity of boronic acids with that of -1,2 diols of dextran/glucose. Initially, the dextran chains wrap the nanoparticle surface due to its high affinity toward A-PBA ( = 6.