Magnetic solid extraction of PCBs in the fruit juices based on polyaniline-modified CoFeO@TiC composite.

Polychlorinated biphenyls (PCBs) have been known pollutants, which are ubiquitous in various matrix, even in some food products and beverages like fruit juices. It is of great importance to develop efficient and simple method to detect them in such matrix. In this work, an effective magnetic composite integrating the advantages of the magnism of CoFeO, hydrophilicity and multisites of TiC and high adsorption properties of polyaniline (CoFeO@TiC@PANI) was designed and synthesized.

Dual COF functionalized magnetic MXene composite for enhancing magnetic solid phase extraction of thiophene compounds from oilfield produced waters prior to GC-MS/MS analysis.

In this study, a novel COF@COF modified magnetic MXene composite (CoFeO @TiC @COF@COF) was synthesized by Schiff base reaction and irre-versible enol-keto tautomerization, and employed to establish a sensitive monitoring method for six thiophene compounds in oilfield produced water samples based on magnetic solid-phase extraction (MSPE) prior to gas chromatography coupled with a triple quadruple mass spectrometer (GC-MS/MS). The designed magnetic materials exhibited unexpected enrichment ability to target thiophene compounds and achieved good extraction efficiencies ranging from 83 % to 98 %. The developed MSPE/GC-MS/MS method exhibited good linearity in the range of 0.

Sensitive visual detection of norfloxacin in water by smartphone assisted colorimetric method based on peroxidase-like active cobalt-doped FeO nanozyme.

Norfloxacin is widely used owing to its strong bactericidal effect on Gram-negative bacteria. However, the residual norfloxacin in the environment can be biomagnified via food chain and may damage the human liver and delay the bone development of minors. Present work described a reliable and sensitive smartphone colorimetric sensing system based on cobalt-doped FeO magnetic nanoparticles (Co-FeO MNPs) for the visual detection of norfloxacin.

Enzymatic Protein Immobilization on Amino-Functionalized Nanoparticles.

The immobilization of proteins on nanoparticles has received much attention in recent years. Among different approaches, enzymatic protein immobilization shows unique advantages because of its site-specific connection. OaAEP1 is a recently engineered peptide ligase which can specifically recognize an -terminal GL residue (-Gly-Leu) and a C-terminal NGL amino acid residue (Asn-Gly-Leu-) and ligates them efficiently.

Resonance frequency and mass identification of zeptogram-scale nanosensor based on the nonlocal beam theory.

Free vibration and mass detection of carbon nanotube-based sensors are studied in this paper. Since the mechanical properties of carbon nanotubes possess a size effect, the nonlocal beam model is used to characterize flexural vibration of nanosensors carrying a concentrated nanoparticle, where the size effect is reflected by a nonlocal parameter. For nanocantilever or bridged sensor, frequency equations are derived when a nanoparticle is carried at the free end or the middle, respectively.

Effect of surface stress on stress intensity factors of a nanoscale crack via double cantilever beam model.

This paper studies the influence of surface elasticity on crack growth for a nanoscale crack advance. A crack is modeled as a double cantilever beam with consideration of surface stress. Using the Euler-Bernoulli beam theory incorporating with surface effects, a governing equation of static bending is derived and bending solution of a cantilever nanowire is obtained for a concentrated force at the free end.