Physics Commons^™

Zno Nanoparticles Modulate The Ionic Transport And Voltage Regulation Of Lysenin Nanochannels, Sheenah L. Bryant, Josh E. Eixenberger, Steven Rossland, Holly Apsley, Connor Hoffman, Nisha Shrestha, Michael Mchugh, Alex Punnoose, Daniel Fologea

Physics Faculty Publications and Presentations

Background: The insufficient understanding of unintended biological impacts from nanomaterials (NMs) represents a serious impediment to their use for scientific, technological, and medical applications. While previous studies have focused on understanding nanotoxicity effects mostly resulting from cellular internalization, recent work indicates that NMs may interfere with transmembrane transport mechanisms, hence enabling contributions to nanotoxicity by affecting key biological activities dependent on transmembrane transport. In this line of inquiry, we investigated the effects of charged nanoparticles (NPs) on the transport properties of lysenin, a pore-forming toxin that shares fundamental features with ion channels such as regulation and high transport rate.

Results: …

Novel Magnetic And Optical Properties Of Sn1−XZnXO2 Nanoparticles, Nevil A. Franco, Kongara M. Reddy, Josh Eixenberger, Dmitri A. Tenne, Charles B. Hanna, Alex Punnoose

Physics Faculty Publications and Presentations

In this work, we report on the effects of doping SnO₂ nanoparticles with Zn²⁺ ions. A series of ∼2–3 nm sized Sn_1−x Zn_xO₂ crystallite samples with 0 ≤ x ≤ 0.18 were synthesized using a forced hydrolysis method. Increasing dopant concentration caused systematic changes in the crystallite size, oxidation state of Sn, visible emission, and band gap of SnO₂ nanoparticles. X-ray Diffraction studies confirmed the SnO₂ phase purity and the absence of any impurity phases. Magnetic measurements at room temperature showed a weak ferromagnetic behavior characterized by an open hysteresis loop. Their …

Comparative Metal Oxide Nanoparticle Toxicity Using Embryonic Zebrafish, Leah C. Wehmas, Catherine Anders, Jordan Chess, Alex Punnoose, Cliff B. Pereira, Juliet A. Greenwood, Robert L. Tanguay

Physics Faculty Publications and Presentations

Engineered metal oxide nanoparticles (MO NPs) are finding increasing utility in the medical fields as anticancer agents. Before validation of in vivo anticancer efficacy can occur, a better understanding of whole-animal toxicity is required. We compared the toxicity of seven widely used semiconductor MO NPs made from zinc oxide (ZnO), titanium dioxide, cerium dioxide and tin dioxide prepared in pure water and in synthetic seawater using a five-day embryonic zebrafish assay. We hypothesized that the toxicity of these engineered MO NPs would depend on physicochemical properties. Significant agglomeration of MO NPs in aqueous solutions is common making it challenging to …

Cytotoxicity Of Zno Nanoparticles Can Be Tailored By Modifying Their Surface Structure: A Green Chemistry Approach For Safer Nanomaterials, Alex Punnoose, Kelsey Dodge, John W. Rasmussen, Jordan Chess, Denise Wingett, Catherine Anders

Physics Faculty Publications and Presentations

ZnO nanoparticles (NP) are extensively used in numerous nanotechnology applications; however, they also happen to be one of the most toxic nanomaterials. This raises significant environmental and health concerns and calls for the need to develop new synthetic approaches to produce safer ZnO NP, while preserving their attractive optical, electronic, and structural properties. In this work, we demonstrate that the cytotoxicity of ZnO NP can be tailored by modifying their surface-bound chemical groups, while maintaining the core ZnO structure and related properties. Two equally sized (9.26 ± 0.11 nm) ZnO NP samples were synthesized from the same zinc acetate precursor …

Magnetism Of Zn-Doped Sno2: Role Of Surfaces, Pushpa Raghani, Balaji Ramanujam

Physics Faculty Publications and Presentations

Surface effects on the magnetization of Zn-doped SnO₂ are investigated using first principles method. Magnetic behavior of Zn-doped bulk and highest and lowest energy surfaces—(001) and (110), respectively, are investigated in presence and absence of other intrinsic defects. The Zn-doped (110) and (001) surfaces of SnO₂ show appreciable increase in the magnetic moment (MM) compared to Zn-doped bulk SnO₂. Formation energies of Zn defects on both the surfaces are found to be lower than those in bulk SnO₂. Zn doping favors the formation of oxygen vacancies. The density of states analysis on the Zn-doped …

Magnetic Properties Of Fe Doped, Co Doped, And Fe+Co Co-Doped Zno, J. J. Beltrán, J. A. Osorio, C. A. Barrero, Charles B. Hanna, A. Punnoose

Physics Faculty Publications and Presentations

The structural, electronic, and magnetic properties of Zn_0.95Co_0.05O, Zn_0.95Fe_0.05O, and Zn_0.90Fe_0.05Co_0.05O nanoparticles prepared by a sol-gel method are presented and discussed. X-ray diffraction and optical analysis indicated that high spin Co²⁺ ions substitute for the Zn²⁺ ions in tetrahedral sites. ⁵⁷Fe Mössbauer spectroscopy showed the presence of isolated paramagnetic Fe³⁺ ions in both Fe doped and Fe+Co co-doped ZnO, however, no evidence of ferromagnetically ordered Fe³⁺ ions is observed. In the Zn_0.95Fe_0.05O sample, weak presence of ZnFe …