Platinum69-cobalt31 alloyed nanosheet nanoassemblies as advanced bifunctional electrocatalysts for boosting ethylene glycol oxidation and oxygen reduction.

Pt-based bimetallic nanocrystals are feasible to dramatically improve the catalytic performances in fuel cells via morphology- and composition-engineering. Herein, bimetallic platinum69-cobalt31 nanosheet nanoassemblies (Pt69Co31 NSNSs) were facilely synthesized through a one-pot co-reduction solvothermal strategy in oleylamine (OAm), using cetyltrimethylammonium chloride (CTAC) and allantoin as the directing agents. The current synthesis highly depended on the critical concentrations of Pt and Co precursors, the combined use of allantoin to OAm as the co-reductant, and the use of proper allantoin concentration. The obtained nanocatalyst exhibited largely enhanced electrocatalytic activity and durable ability towards ethylene glycol oxidation reaction (EGOR) and oxygen reduction reaction (ORR) relative to home-made Pt85Co15 nanoparticles (NPs), Pt19Co81 NPs and Pt black catalysts due to its much larger electrochemically active surface area than the contrasts.

A novel label-free electrochemical immunosensor based on the enhanced catalytic currents of oxygen reduction by AuAg hollow nanocrystals for detecting carbohydrate antigen 199.

Herein, bimetallic alloyed AuAg hollow nanocrystals (AuAg HNCs) were prepared by a simple one-pot aqueous method using polycytidysic acid (PCA) as the green growth-directing agent. The novel immunosensor for carbohydrate antigen 199 (CA199) was further constructed based on the enhanced catalytic currents of oxygen reduction reaction (ORR) by AuAg HNCs. By virtue of the good biocompatibility and catalytic activity of AuAg HNCs, the immunosensor exhibited superior analytical performance for the assay of CA199 under the optimal experimental conditions, the ORR signals linearly decreased with the increased CA199 concentrations in the range of 1 ~ 30UmL-1, with the low detection limit of 0.228UmL-1, improved stability, reproducibility and selectivity.

l-Arginine-assisted one-pot synthesis of hierarchical Ag1Pt2 nanocorallines for surface-enhanced Raman spectroscopy.

The hierarchical multi-branched Ag1Pt2 nanocorallines (NCs) were prepared in a large scale by a rapid aqueous method, using l-arginine as the eco-friendly shape-directing agent. The product was mainly characterized by microscopy measurements, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The architectures exhibited superior surface-enhanced Raman scattering (SERS) with 4-nitrothiophenol (4-NTP), the enhancement factor (EF) of 1.3×105, a wide linear range of 10-100µM and a low detection limit of 0.01µM. Meanwhile, the SERS-active substrate was explored for the assay of 4-mercaptobenzoic acid (4-MBA) with significantly enhanced SERS performance. It means Ag1Pt2 NCs as a good Raman-active platform for sensing in food and environment analysis, owing to their rough surfaces and unique multi-branched structures.