Use of Moessbauer Spectroscopy for Careful Assessment of Magnetic Nanoparticles

The use of Mossbauer spectroscopy is a simple and direct way to determine the amounts of magnetite and maghemite in an otherwise unknown sample. Quentin Pankhurst et al wrote a nice paper about how to use it and determine magnetite/maghemite weighting directly from the mean isomer shift of the total spectrum, which means that one can apply a simple model-independent curve-fitting methodology. Compared to the older way of using Moessbauer, this takes an awful lot of the work out of the process.

Check out the paper for yourself here.

How to Reliably Measure the SAR of Magnetic Hyperthermia Materials

Wildeboer, Southern and Pankhurst published recently a paper about the reliable measurement of specific absorption rates and intrinsic loss parameters in magnetic hyperthermia. They also carefully reviewed how to cope with non-adiabatic measurement conditions. This paper might very useful for the novice and more experienced user, as they went pretty thoroughly through the methodologies, and have tried to make some recommendations for both the measurement procedure, and the analysis method, that anyone will be able to follow.

Check out this very useful paper here.

Magnetic Carrier Meeting 2014

Our already 10th International Conference on the Scientific and Clinical Applications of Magnetic Carriers took place in Dresden, Germany from June 10-14, 2014. It was a wonderful gathering of more than 330 participants from 41 countries, where we discussed all the different aspects of magnetic nanoparticles and microspheres, how they can be made, used and applied in new and ever more fascinating ways!

Check out all the details at

       http://magneticmicrosphere.com/meeting-tenth

The research discussed at the meeting has now been published in full-size peer-reviewed papers in the Journal of Magnetism and Magnetic Materials (JMMM). Check it out here.

How Good Are We at Making Magnetic Nanoparticles?

In a recent review - called a perspective - Lucia Gutierrez and collaborators wrote a nice discussion of the current state of the art in making magnetic nanoparticles. They write that many different single-core and multi-core magnetic iron oxide nanoparticles are being made for biomedical applications. There are more examples of multi-core magnetic particles than single-core ones, especially since coating of particle aggregates within a matrix will result in multi-core particles. However, it is difficult to control the number of cores, inter-core distances and spatial distribution when generating multi-core particles.

Many parameters of the synthesis procedure may have a strong effect on the particles obtained, including temperature, reagent concentrations, surfactant concentrations, and stirring conditions. This is one of the reasons why scaling-up of some of these synthesis routes is extremely complicated. Indeed, one of the difficulties that particle synthesis faces is in batch-to batch reproducibility. This has led to recent work on alternative reaction platforms that can offer more consistent results. One such platform is the use of microwave irradiation as a heating source.

Check out this interesting paper here.

Correction to "Synthesis of Magnetic Noble Metal (Nano)Particles" Paper

It is never fun to have to admit to a scientific error. However, it is truly appreciated by people discussing a specific paper and not being able to reproduce something. Ramachandran et al. just published a correction in an upcoming Langmuir paper. They had in an earlier paper reported about highly magnetic metallic nanoparticles. Which at the end turned out to be contaminations with iron, as seen by scanning electron microscopy (SEM) and energy-dispersive X-ray
spectroscopy (EDS) mapping. Thank you for being honest and pointing our magnetic particle community to possible problems with today's highly sensitive analysis methods.

Inorganic Janus Particles for Biomedical Applications

Based on recent developments regarding the synthesis and design of Janus nanoparticles, they have attracted increased scientific interest due to their outstanding properties. There are several combinations of multicomponent hetero-nanostructures including either purely organic or inorganic, as well as composite organic–inorganic compounds. Janus particles are interconnected by solid state interfaces and, therefore, are distinguished by two physically or chemically distinct surfaces. They may be, for instance, hydrophilic on one side and hydrophobic on the other, thus, creating giant amphiphiles revealing the endeavor of self-assembly. Novel optical, electronic, magnetic, and superficial properties emerge in inorganic Janus particles from their dimensions and unique morphology at the nanoscale. As a result, inorganic Janus nanoparticles are highly versatile nanomaterials with great potential in different scientific and technological fields. In this paper, we highlight some advances in the synthesis of inorganic Janus nanoparticles, focusing on the heterogeneous nucleation technique and characteristics of the resulting high quality nanoparticles. The properties emphasized in this review range from the monodispersity and size-tunability and, therefore, precise control over size-dependent features, to the biomedical application as theranostic agents. Hence, we show their optical properties based on plasmonic resonance, the two-photon activity, the magnetic properties, as well as their biocompatibility and interaction with human blood serum.

Check this excellent review out here.

Stabilization of the Surfaces of Magnetite

Accurate structures of iron oxide surfaces are important for understanding their role in catalysis, and, for oxides such as magnetite, applications in magnetism and spin physics. The accepted low-energy electron diffraction (LEED) structure for the surface of magnetite, in which the bulk surface termination undergoes an undulating distortion, has a relatively poor agreement with experiment. Bliem et al. show that the LEED structure is much more accurately described by a structure that includes subsurface cation vacancies and occupation of interstitial sites (see the Perspective by Chambers). Such cation redistribution occurs in many metal oxides and may play a role in their surface structures.

Check it out at Science 5 December 2014:Vol. 346 no. 6214 pp. 1215-1218, DOI:10.1126/science.1260556

Handling of Magnetic Beads in Microfluidics

Spinomix SA, a Swiss technology platform company announced the approval of two US patents while three others are pending approval. The two US Patents are number US 8,585,279 and US 8,870,446 relating to the manipulation and mixing of magnetic particles in microfluidics environments.Spinomix provides innovative sample processing solutions to the life sciences sector. The company’s unique MagPhase technology enables homogenous handling of magnetic beads in microfluidics based systems, thus enhancing bioassay efficiency and in a further step, allowing for sample processing automation. MagPhase technology is currently applied in nucleic acid purification, a market estimated to represent over one billion dollars. The vision of the company is to expand the use of microfluidic cartridges into additional areas, such as protein purification or cell isolation.

To read more, check out Spinomix website.