Herein we report on the use of different metal precursors in the synthesis of MoSe₂ nanomaterials in order to control their morphology. The use of Mo(CO)₆ as the metal precursor resulted in the formation of wrinkled few-layer nanosheets, while the use of H₂MoO₄ as the metal precursor resulted in the formation of nanoflowers. To investigate the effect of the morphologies on their performance as catalysts in the hydrogen evolution reaction, electrochemical characterization was done using linear sweep voltammetry (LSV), cyclic voltammetry (CV), and electrical impedance spectroscopy (EIS). The MoSe₂ nanoflowers were found to have superior electrochemical performance towards the hydrogen evolution reaction with a lower Tafel slope, on-set potential, and overpotential at 10 mA/cm² compared to the wrinkled few-layer nanosheets. This was found to be due to the higher effective electrochemical surface area of the nanoflowers compared to the nanosheets which suggests a higher number of exposed edge sites in the nanoflowers.

The use of high catalyst loading is required for most of the organocatalyzed asymmetric aldol reactions in organic synthesis, and this often presents challenges during purification and difficulties in catalyst recovery from the reaction mixture. The immobilization of the catalyst onto gold nanoparticles (AuNPs) can change the structural conformations of the catalyst, thereby improving its catalytic activity and reusability. Herein we report on the synthesis of aldolase mimetic peptide coupled to gold nanoparticles (AuNPs) as efficient organocatalysts for asymmetric aldol reaction. AuNPs were synthesized using the Turkevich method. The conjugation of the peptide to AuNPs was characterized using surface plasmon resonance (SPR), Raman and X-ray photoelectron spectroscopy, and transmission electron microscopy (TEM) was used for particle size determination. The produced nanoparticles, whose sizes depended on the reduction method, were quasi-spherical with a relatively narrow size distribution. The peptide–AuNP conjugates were evaluated for aldol reaction catalytic activity between carbonyls p-nitrobenzaldehyde and cyclohexanone. The products were obtained with good yields (up to 85%) and enantioselectivity (up to 94%). The influence of organic solvents, pH and buffer solutions was also investigated. The results showed that the buffer solutions regulated the colloidal stability of AuNPs, resulting in a significant enhancement in the catalytic rate of the peptide–AuNP conjugate.

This study reports on the optimization of Malaria RDTs, targeting histidine-rich protein-2 (HRP-2) in human blood samples. Gold nanoparticles (AuNPs) bioconjugates prepared using monoclonal antibodies PTL3, 4H48 and IB47 were synthesized, characterized, and employed as colourimetric markers/reporters. The conjugates were tested against detector antibodies (CH1-13, 4H46 and DH60), which were immobilized as test lines using WHO-approved positive samples from multiple geographic areas (Nigeria, Santa Lucia, Benin, Philippine and the United States of America). All AuNP bioconjugates exhibited high stability, with an average gold particle size of 40 nm. Amongst the tested conjugates, AuNPs bioconjugates of PTL3-CH3 pair combination resulted in high intensity of both test and control lines. Further optimisation of the PTL3 conjugate across pH 7.5, 8.5, and 9.5 revealed that pH 9.5 produced the highest chromaticity-derived intensity values. This chromaticity-guided optimisation strategy enables objective colour quantification and offers a robust framework for improving RDT performance and quality control.