Evaluating Novel Bio-Assembled Materials with Low-Voltage Transmission Electron Microscopy (LV-TEM)

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Layered Aluminosilicate Materials
About Delong America


There is an increasing interest to create new materials with never-before-seen synergistic properties or additional functionality. One way that this is done is to combine several materials with different properties for creating a new hybrid material. It is many-a-times a challenge to get these materials together at the nanoscale.

A study published in ACS Applied Materials and Interfaces, with authors from The Materials and Manufacturing Directorate at the US Air Force Research Laboratory, shows an interesting new way to do just that.

The study, titled “Bioassembled Layered Silicate-Metal Nanoparticle Hybrids” uses a “biological blueprint” as a method to functionalize the surface of “layered aluminosilicate nanoparticles” with metal nanoparticles.

The benefits of using molecular building blocks (amino acids, proteins, and enzymes) for designed organization of hybrid nanostructures has been shown many times in the past. For instance, certain proteins have been shown to bind strongly to specific nanomaterials.

They can be used as a biological blueprint or as biolinkers to direct the assembly of materials into predefined structures. This study is one of the first time that the interaction between layered silicates and biological materials has been examined.

Layered Aluminosilicate Materials

Layered aluminosilicate (LA) materials have been studied for applications as diverse as polymer nanocomposites, drug delivery, sensing, and hemostatic agents among others. Most of these application areas will benefit from an increase in the functionality of the LA. This is the objective of using the biological material to help guide the modification of the LA into more useful varieties.

According to this research, hybrid structures derived from a “biological blueprint” have been shown to have interesting new properties. For instance, some of these new hybrid nanoparticles are responsive to a weak external magnetic field that enables novel magneto-optical fluids.

These fluids can be optically opaque or translucent, based on the absence or presence of a magnetic field. Others display heating during exposure to RF radio waves. These functional properties have much value in applications ranging from sensors to cancer treatments.


The LVEM5 played an important role in this research. The scale of the materials being studied necessitated electron microscopy in order to evaluate the binding of the nanomaterials to the biological template, as well as understand if the materials were being assembled together as predicted.

In conventional TEM biological materials, such as phages need to be stained with heavy metals in order to be resolved. In this study, adding heavy metal stains will make it tough to understand if the phages are bound to the nano-materials. Low-Voltage Electron Microscopy (LVTEM) enables the operator to visualize biological materials at the nanoscale without the use of these destructive heavy metal stains.

Low-voltage transmission electron microscopy (LVTEM) of NaMMT particles with the biopanned phage clones qualitatively showed selective binding to the aluminosilicate layers is shown in Figure 1. For instance, the phage clone expressing M1 exhibited binding to the MMT sheets as shown in Figure 1C, whereas the M13 phage displaying a non-specific peptide showed little or no binding to the MMT and in Figure 1B.

Figure 1. (A) Schematic illustration of the M13 bacteriophage showing the displayed peptides on the pIII coat protein, (B) Low- voltage transmission electron microscope (LVEM5) micrograph of MMT sheets incubated with phage displaying a non-specific peptide, (C) Low-voltage transmission electron microscope (LVEM5) micrograph of MMT sheets incubated with phage displaying the specific M1 peptide.

About Delong America

The Delong group of companies operates in the high tech, engineering design, manufacturing and sales sectors and span two continents with operations in Europe and North America.

Our facilities in Brno, Czech republic are specialized in the design and manufacturing of precision components and electron optics and vacuum technologies. In the summer of 2007 Delong will open its new building which will be equipped with the latest in design and precision manufacturing innovations.

This information has been sourced, reviewed and adapted from materials provided by Delong America.

For more information on this source, please visit Delong America.

Date Added: Dec 18, 2013 | Updated: Dec 19, 2013
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