Nanotechnology Role Development for COVID-19 Pandemic ManagementRead the full article
Journal of Nanotechnology publishes papers related to the science and technology of nanosized and nanostructured materials, with emphasis on their design, characterization, functionality, and preparation for implementation in systems and devices.
Journal of Nanotechnology maintains an Editorial Board of practicing researchers from around the world, to ensure manuscripts are handled by editors who are experts in the field of study.
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Electrochemically Effective Surface Area of a Polyaniline Nanowire-Based Platinum Microelectrode and Development of an Electrochemical DNA Sensor
Electrochemical DNA sensors based on nanocomposite materials of polyaniline nanowires (PANi NWs) have been published in the literature. However, it is interesting that there are very few research studies related to the development of electrochemical DNA sensors based on PANi NWs individually. In this study, PANi NWs were synthesized site-specifically on a Pt microelectrode with only 0.785 mm2 area using an electropolymerization procedure. The electrosynthesis allows direct deposition of PANi NWs onto the Pt microelectrode in a rapid and cost-effective way. The good properties of PANi NWs including uniform size, uniform distribution throughout the Pt working electrode, and H2SO4 doping which improved the conductivity of the PANi material were obtained. Especially, the electrochemically effective surface area of the PANi NW-based Pt microelectrode determined in this work is nearly 19 times larger than that of the Pt working electrode. The PANi NW layer with large electrochemically effective surface area and high biocompatibility is consistent with the application in electrochemical DNA sensors. The fabricated DNA sensors show advantages such as simple fabrication, direct detection, high sensitivity (with the detection limit of 2.48 × 10−14 M), good specificity, and low sample volume requirement. This study also contributes to confirm the role of PANi NWs in DNA probe immobilization as well as in electrochemical signal transmission in the development of electrochemical DNA sensors.
Emerging Roles of Green-Synthesized Chalcogen and Chalcogenide Nanoparticles in Cancer Theranostics
The last few decades have seen an overwhelming increase in the amount of research carried out on the use of inorganic nanoparticles. More fascinating is the tremendous progress made in the use of chalcogen and chalcogenide nanoparticles in cancer theranostics. These nanomaterials, which were initially synthesized through chemical methods, have now been efficiently produced using different plant materials. The paradigm shift towards the biogenic route of nanoparticle synthesis stems from its superior advantages of biosafety, eco-friendliness, and simplicity, among others. Despite a large number of reviews available on inorganic nanoparticle synthesis through green chemistry, there is currently a dearth of information on the green synthesis of chalcogens and chalcogenides for cancer research. Nanoformulations involving chalcogens such as sulfur, selenium, and tellurium and their respective chalcogenides have recently emerged as promising tools in cancer therapeutics and diagnosis. Similar to other inorganic nanoparticles, chalcogens and chalcogenides have been synthesized using plant extracts and their purified biomolecules. In this review, we provide an up-to-date discussion of the recent progress that has been made in the plant-mediated synthesis of chalcogens and chalcogenides with a special focus on their application in cancer theranostics.
Role of Nanobiotechnology Towards Agri-Food System
The major challenge of modern agriculture is to satisfy actual and future global food demands efficiently. This great challenge requires combined efforts to preserve natural resources to support intensive agriculture while limiting detrimental impacts on the environment. One of these efforts is using nanobiotechnology. Nanobiotechnology is the application of nanotechnology in biological science. Nanotechnology is the science of manipulating materials at the nanoscale (1 nm = 10ˉ⁹ m). This review summarizes the potential of nanobiotechnology for its importance in increasing yield in agriculture and providing consumers with quality and contamination-free food. In the agriculture sector, nanobiotechnology is necessarily used as fertilizers (nanofertilizers) for crop yield improvement, pesticides (nanopesticides) for crop protection, and nanobiosensors for the detection of crop pathogens, soil conditions, and vegetation conditions, Similarly, intelligent food packaging, and detection of pathogens, adulterants, and toxins in food are its importance in the food sector.
Graphene Oxide Nanoadsorbent for the Removal of Fluoride Ion from Groundwater: Adsorbent Performance and Adsorption Mechanism
The deterioration of the quality of groundwater by fluoride is the cause of shortage of drinking water supply in the rift valley region. Most people living in the rural areas are using groundwater as the source of their potable water; however, it is contaminated with high concentrations of fluoride ion above the permissible level. Hence, this study was designed to investigate the adsorption of fluoride from groundwater by graphene oxide (GO) under specific conditions, such as: agitation rate of 120 rpm, contact time of 90 minutes, adsorbent dosage of 0.42 mg/L, initial fluoride concentration of 10 mg/L, and pH of 6.8. The result obtained showed 99.3% fluoride removal from the NaF prepared solution and 91.6% fluoride removal from the real sample. The retained properties of GO after adsorption observed on UV–Vis analysis confirmed that the adsorbent can be recyclable. The result obtained also showed that the adsorption kinetics with the coefficient of determination (R2) for pseudo-second order (SSO) and pseudo-first order (SFO) were 0.99 and 0.96, respectively. Based on these results, the adsorption of fluoride onto GO is a pseudo-second-order kinetics type. According to the result, the Freundlich isotherm model showed a good fit to the experiment with R2 (0.99). The adsorption capacity of the adsorbent was found to be 301.43 mg/g. Hence, this study showed that GO is the preferred adsorbent for the removal of fluoride from groundwater.
Synthesis, Characterization, and Evaluation of the Remediation Activity of Cissus quadrangularis Zinc Oxide Nanoparticle-Activated Carbon Composite on Dieldrin in Aqueous Solution
In this study, zinc oxide-activated carbon nanocomposite was used as the adsorbent for the remediation of dieldrin in aqueous media. Zinc oxide nanoparticles (ZNPs) were synthesized from Cissus quadrangularis (C. quadrangularis) leaf extract, and activated carbon was derived from maize cobs. Nanocomposites were formulated by mixing the ZNPs with the activated carbon in a ratio of 1 : 50. The UV-Vis spectra showed a complete reduction of Zn2+ to Zn0 with plasmon resonance bands in the range of 361–376 nm, which is a characteristic of ZNPs. The SEM images of ZNPs showed hexagonal-shaped particles of 15–20 nm, with face-centered cubic crystals, as demonstrated by XRD analysis. FTIR results showed absorption bands in the ranges 3500–3100 cm−1 (N-H stretch), 3400–2400 cm−1 (O-H stretch), 988–830 cm−1 (C-H bend), 1612 cm−1 (C=C stretch), 400–600 cm−1 (Zn-O stretch), and 1271 cm−1 (C-O bend). Batch adsorption experiments were performed using 20 ml of dieldrin solution at varying pH values (1–14), concentrations (5–100 ppm), temperatures (293–323 K), adsorbent dosages (0.01–0.12 g), and contact times (30–180 minutes) to determine the optimum conditions. The calculated thermodynamic parameters (ΔH°, ΔS°, and ΔG°) indicated that the adsorption was spontaneous and exothermic in nature, implying decreasing randomness of dieldrin molecules at the solid-liquid interface. The isotherm and adsorption kinetics for the composite showed that the absorption process followed Langmuir isotherm and pseudo-second-order kinetics. Adsorption capacities of the nanoparticles, activated carbon, and nanocomposite at a reaction time of 120 minutes and pH of 7 were 3.72 ± 0.068 mg/g, 3.92 ± 0.061 mg/g, and 4.0 ± 0.102 mg/g, respectively, with corresponding percentage removals of 93.12 ± 0.044, 98.04 ± 0.044, and 99.76 ± 0.332. Thus, the nanocomposite exhibited a better sorbing potential for dieldrin in solution than activated carbon. This study recommends testing the remediation potential of the synthesized nanocomposite on other persistent organic pollutants.
Optical Investigation of p-GaAs/i-GaN0.38yAs1-1.38ySby/n-GaAs Quantum Wells Emitters
We have studied the 1.55 μm optical properties of p-GaAs/i-GaN0.38yAs1-1.38ySby/n-GaAs quantum wells using a self-consistent calculation combined with the anticrossing model. We have found that the increase of injected carriers’ density induces the increase of optical gain and radiative current density. The rise of doping density causes a blue shift of the fundamental transition energy accompanied with significant increase of optical gain. The quantum-conﬁned Stark effect on radiative current density is also studied. The variation of radiative current as function of well width and Sb composition is also examined. In order to operate the emission wavelength at the optical fiber telecommunication domain, we have adjusted the well parameters of p-GaAs/i-GaN0.38yAs1-1.38ySby/n-GaAs.