Highly sensitive label-free amperometric immunoassay of prostate specific antigen using hollow dendritic AuPtAg alloyed nanocrystals.

Herein, well-defined hollow dendritic AuPtAg alloyed nanocrystals (ANCs) were synthesized by a simple L-proline-mediated one-pot aqueous method. More importantly, the synthesized hollow dendritic architectures provide a suitable platform for immobilization of anti-prostate specific antigen (PSA). The resultant label-free immunosensor exhibited the improved performance for highly sensitive detection of PSA based on the enhanced catalytic currents of K3[Fe(CN)6] as a signal probe. Impressively, the immunosensor showed the wide linear range of 0.05-50 ng mL-1 and low detection limit of 0.017 ng mL-1 under optimal conditions for the assay of PSA, couple with the improved stability, reproducibility and selectivity. It provides a promising platform for clinical research and diagnosis.

Simple synthesis of hierarchical AuPt alloy nanochains for construction of highly sensitive hydrazine and nitrite sensors.

Herein, a single-step co-reduction aqueous route was designed for preparation of hierarchical AuPt alloy nanochains, firstly using amprolium hydrochloride as a new stabilizing agent and structure-director. The morphology, structure, composition, and size of the products were characterized by a series of technique. The growth mechanism of AuPt nanochains was discussed in details. The AuPt nanochains modified glassy carbon electrode showed the improved analytical performances for determination of nitrite and hydrazine. The linear ranges of nitrite are 0.5-366.4µM and 466.4-2666.4µM for the two segments, and the detection limit is 0.03µM (S/N=3). The linear ranges of hydrazine are 5.0-116.4µM and 166.4-2666.4µM for the two segments, along with the low detection limit of 0.26µM (S/N=3). The performances of AuPt nanochains were superior to those of individual Pt and Au nanoparticles. It is ascribed to the specific hierarchical structures and synergistic effects of the bimetals.

l-Glutamic acid assisted eco-friendly one-pot synthesis of sheet-assembled platinum-palladium alloy networks for methanol oxidation and oxygen reduction reactions.

In this work, bimetallic platinum-palladium sheet-assembled alloy networks (PtPd SAANs) were facilely synthesized by an eco-friendly one-pot aqueous approach under the guidance of l-glutamic acid at room temperature, without any additive, seed, toxic or organic solvent involved. l-Glutamic acid was served as the green shape-director and weak-stabilizing agent. A series of characterization techniques were employed to examine the morphology, structure and formation mechanism of the product. The architectures exhibited improved electrocatalytic activity and durable ability toward methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) in contrast with commercial Pt black and Pd black catalysts. This is ascribed to the unique structures of the obtained PtPd SAANs and the synergistic effects of the bimetals. These results demonstrate the potential application of the prepared catalyst in fuel cells.