Large Scale Synthesis of Nickel Oxide (Nio) by Self Propagated Combustion Reaction

An octahedral metal oxide nanoparticle-based dual-signal sensing platform for simultaneous detection of histidine and lysine in human blood plasma and urine

Histidine and lysine serve as essential amino acids in physiological processes and biomarkers for specific diseases, requiring precise detection methods in a variety of samples. This study presents an affordable single colorimetric probe that employs nickel oxide nanoparticles (NiONPs) as an artificial enzyme to detect histidine and lysine, improving conventional analytical limitations. The characterization of NiONPs was executed using SEM-EDX, FE-SEM, FTIR and XRD. The NiONPs demonstrated peroxidase-like catalytic activity on the conversion of TMB to oxidized TMB (oxTMB) in the presence of H2O2, utilizing optimization parameters like pH value (3), TMB concentration (10 mM), H2O2 concentration (60 mM), and incubation time (18 min). The study revealed that Ni and O atoms are present on the surface of NiONPs, allowing for specific interactions with essential amino acids and temporarily hindering the catalytic activity of oxidized TMB. The method exhibited a low limit of detection (LOD) of 0.07 μM (10-100 μM) for histidine and 1.1 μM (15-150 μM) for lysine with good stability. The proposed strategy was validated with urine and plasma samples, yielding favorable recoveries of 93.6-98.2% in urine and 90.5-96.0% in plasma for histidine and 91.2-94.8% in urine and 88.4-93.3% in plasma for lysine, supporting its selectivity, feasibility, and reliability for practical applications. In the future, this methodology will facilitate the integration of histidine and lysine detection into microfluidic systems using NiONPs as a colorimetric probe.

Surfactant effect on energy storage performance of hydrothermally synthesized Ni3V2O8

We report a study to improve the ternary oxide Ni3V2O8's electrochemical energy storage capabilities through correct surfactanization during hydrothermal synthesis. In this study, Ni3V2O8nanomaterials were synthesized in three different forms: one with a cationic surfactant (CTAB), one with an anionic surfactant (SLS), and one without any surfactant. FESEM study reveals that all the synthesized Ni3V2O8nanomaterials had a small stone-like morphology. The electrochemical study showed that anionic surfactant-assisted Ni3V2O8(NVSLS) had a maximum of 972 F g-1specific capacitance at 1 A g-1current density, whereas cationic surfactant-assisted Ni3V2O8(NVCTAB) had the lowest specific capacitance of 162 F g-1. The specific capacitance and the capacitance retention of the NVSLS(85% after 4000 cycles) based electrode was much better than that of the NVCTAB(76% after 4000 cycles) based electrode. The improved energy storage properties of the NVSLSelectrode are attributed to its high diffusion coefficient, high surface area, and enriched elemental nickel, as compared to the NVCTABelectrode. All these excellent electrochemical properties of NVSLSelectrode indicates their potential usage in asymmetric supercapacitor application.

Nickel oxide nanoparticles synthesis using plant extract and evaluation of their antibacterial effects on Streptococcus mutans

Dental decay is known in the world as the most common human infectious disease. Ascending process of dental caries index in the world shows the failure of oral disease prevention. Streptococcus mutans bacteria cause acid damage and tooth decay by producing acid over time. Nanomaterials with suitable functionality, high permeability, extremely large surface area, significant reactivity, unique mechanical features, and non-bacterial resistance can be considered as promising agents for antimicrobial and antiviral applications. In this study, nickel oxide (NiO) nanoparticles with size range from 2 to 16 nm containing Stevia natural sweetener were eco-friendly synthesized via a simple method. Additionally, their various concentrations were evaluated on S. mutans bacteria by applying the broth dilution method. The results demonstrated that these spherical NiO nanoparticles had efficient bacteriostatic activity on this gram-positive coccus.

Chitosan capped nickel oxide nanoparticles as a saturable absorber in a tunable passively Q-switched erbium doped fiber laser

Nickel oxide (NiO) nanoparticles successfully prepared from a nickel(ii) chloride hexahydrate precursor are used to form a chitosan capped NiO nanoparticle thin film to serve as a saturable absorber (SA) for the generation of passively Q-switched pulses in an erbium doped fiber laser (EDFL). The NiO/chitosan SA based EDFL is able to generate stable pulsed outputs at a low threshold pump power of 104.90 mW with a central wavelength at 1562 nm. The highest pulse energy obtainable by the system is 15.30 nJ at a repetition rate of 42.66 kHz and a pulse duration of 2.02 μs. The laser has a spectral range of 58 nm from 1522 to 1580 nm, covering the C and L bands and even portions of the S band. This study experimentally demonstrates that the potential of the NiO/chitosan film as an SA material for Q-switching operations, combined with the biocompatibility, non-toxicity and high thermal resistance of Chitosan, holds great prospects for a broad range of applications.