Published
Table of Contents
Open AccessArticles
by Muhammad Ikrama
2023,1(1);
590 Views
Abstract
In this research, nickel sulfide (NiS) quantum dots (QDs) were prepared through the co-precipitation method and annealed at same temperature with different time. This study aimed to check the influence of annealing time on catalytic reduction of rhodamine B () and antibacterial efficacy against E. coli. The synthesized NiS were characterized thorough XRD, UV-Vis, SAED and TEM analysis to check the effect of annealing time on structural, optical and morphological of QDs. XRD spectra depicted that crystallinity of the NiS increased upon enhancing the annealing time. Electronic transition spectroscopy exhibited the blue shift by increasing annealing time, leading to band gap energy enhancement. TEM images demonstrated that agglomeration of the QDs increased by increasing the annealing time. EDS spectra verified the formation of NiS QDs. SAED analysis confirmed the polycrystalline behavior of host and annealed NiS. The pure NiS demonstrated substantial catalytic reduction of dye in acidic medium comparison to other media. Moreover, host sample (NiS) exhibited maximum inhibition zone for E. coli at higher concentration.
show more
Open AccessArticles
by P. Reddy
2023,1(1);
514 Views
Abstract
In this study, Zr-doped HfO2 (HZO) based resistive random-access memory (RRAM) device were fabricated. The Hf:Zr (1:1) ratio in the HZO films were controlled by changing the HfO2 and ZrO2 cycle ratio during the atomic layer deposition (ALD) process. Next, we studied the structural and electrical properties of the Au/HZO/TiN RRAM device structure. The RRAM devices exhibits an excellent resistance ratio of the high resistance state (HRS) to the low resistance state (LRS) of ~103 A, and as well as good endurance (300 cycles) and retention (>103 s), respectively. Further, the device showed different conduction mechanism in LRS and HRS modes. The lower biased linear region is dominated by ohmic conductivity, whereas the higher biased nonlinear region is dominated by a space charge limited current conduction. This device is suitable for application in future high-density nonvolatile memory RRAM devices.
show more
Open AccessArticles
by Saeed Reza Hormozi Jangi
2023,1(1);
372 Views
Abstract
Despite the well-known concepts on the intrinsic peroxidase-like activity of MnO2 nanoparticles, up to date, their biochemical and kinetics characteristics were not investigated, especially, the current information about their performances toward n-electron oxidation of 3, 3′-diaminobezedine for producing indamine polymers is on limitation. Therefore, herein, the MnO2 nanoparticles were synthesized by a simple low-cost co-precipitation method and then characterized by XRD, SEM, and DLS analysis. Besides, their peroxidase-like activity was evaluated upon standard peroxidase enzyme assay, revealing high intrinsic peroxidase-like activity for the as-mentioned MnO2 nanozymes. Considering their high intrinsic peroxidase-like activity, their optimal biochemical characteristics were quantified by probing the progress of -electron irreversible oxidation of 3, 3′-diaminobezedine in the presence of MnO2 nanozymes as peroxidase mimics. The maximal activity of the as-mentioned MnO2 nanoparticles with high intrinsic peroxidase-like activity was observed when the pH and temperature of the reaction media were fixed over 3.0–6.0 and 23℃–25℃, in order, revealing very high pH and thermal stability of the as-prepared nanoparticles. The salt stability of these nanoparticles was also checked using NaCl as model salt, revealing that the nanozymatic activity was stable over a salt concentration as high as 3–7 M. In addition, the affinity constant (Km) and maximum velocity of the nanozyme-catalyzed oxidation of 3, 3′-diaminobezedine were found to be 1.6 mM and 47 nM sec−1, in turn.
show more
Open AccessArticles
by Saeed Reza Hormozi Jangi
2023,1(1);
378 Views
Abstract
In this contribution, the biochemical characterization of enzyme-like nanosilvers was performed toward nanozyme-catalyzed oxidation reactions. In this regard, silver nanoparticles were synthesized via a simple chemical reduction method and then characterized by the TEM imaging method. Afterward, their enzyme-like activity was investigated toward catalysis of the oxidation reaction of 3,3’,5,5’-tetramethyl-benzidine (TMB) as one of the most popular peroxidase substrates. The results exhibited a specific nanozymatic activity as high as 5400 nM min−1 for the as-synthesized nanosilvers toward TMB oxidation. Due to the high enzyme-like activity ofthe as-prepared nanosilvers, their biochemical properties including pH, thermal, light, and shelf stability were characterized to explore more precisely describing their nanozymatic behavior. The results ofthermal and pH stability studies showed that the as-prepared nanosilvers reveal their maximal enzyme-like activity at a wide temperature range of 25℃–35℃ and a pH range of 3.5–4.5, in order. Regarding the light stability and shelf-life studies, the results exhibited that 75% and 96% of the enzyme-like activity of the as-prepared nanozymes was saved after 7 days exposing visible light and 10 days of storage at 4℃ under dark conditions, in order.
show more
Open AccessArticles
by Chong Qiu
2023,1(1);
278 Views
Abstract
N/A
show more