Alzheimer's Peptide Aβ1-42, an amyoid beta peptide, is found in plagues in the brains of Alzheimer's disease patients, and accumulation of this very hydrophobic peptide is thought to be the direct cause of the disease. However, the reason for accumulation is not clear. A common theory is that the balance between production and degradation of this peptide is disrupted in the disease. One method whereby degradation of the peptide can be inhibited is by modification into a form which is resistant to enzymatic degradation (proteolysis). In peptides, isomerization of aspartic acid into isoaspartic acid (where the peptide bond is via the side-chain beta carbon rather than the normal backbone alpha carbon) is known to inhibit enzymatic degradation, and may be the elusive Alzheimer's "trigger", which results in decreased degradation and therefore accumulation of the peptide. Nadia Sargaeva of Prof.  Peter O'Connor's group has developed a new mass spectrometric method for detecting this isomerization and tested it out on the worst variant of the amyloid beta peptide, the full length version containing amino acids 1-42. 

Read the paper 

I. Hancox, K. V. Chauhan, P. Sullivan, R. A. Hatton, A. Moshar, C. P. A. Mulcahy and T. S. Jones

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We report a 60% increase in open circuit voltage (V_oc) and power conversion efficiency in a chloroaluminium phthalocyanine (ClAlPc)/fullerene (C₆₀) planar heterojunction photovoltaic device after insertion of a MoO₃ hole-extracting layer at the interface between the indium tin oxide (ITO) electrode and the ClAlPc donor layer, with an associated improvement in device stability. A similar improvement was observed in heterojunction devices based on mixed ClAlPc/C₆₀ layers. We propose that the improvements in device performance are due to the pinning of the ITO Fermi level to the valance band of the MoO₃ interlayer, where the latter is closely aligned with the highest occupied molecular orbital of ClAlPc.

 

http://dx.doi.org/10.1039/b915764f

Giovanni Constantini and collaborators report in ACS Nano: The ion beam deposition (IBD) of rhodamine dye molecules on solid surfaces in high vacuum is explored in order to characterize the possibility of fabricating molecular coatings or nanostructures from nonvolatile molecules. Molecular ion beams with a well-defined composition are deposited on silicon oxide surfaces with a controlled kinetic energy. Photoluminescence spectroscopy and time-of-flight secondary ion mass spectrometry (TOF-SIMS) are employed in order to characterize the sample with respect to coverage, homogeneity, and the fraction of intact landed ions (soft-landing ratio). We find that homogeneous rhodamine films of defined composition can be produced at energies of 2−100 eV. The coverage is found to be proportional to the ion dose. Soft-landing is observed for energies up to 35 eV.  http://dx.doi.org/10.1021/nn900022p

Stefan Schumann, Stefan Bon, Ross Hatton and Tim Jones report in Chem.Commun: Vertical co-deposition of sub-100 nm polystyrene sphere templates with water-soluble small molecule or polymeric semiconductors, followed by solvent vapour assisted sphere removal, is shown to be an excellent method for generating porous large area organic semiconductor thin films with sub-100 nm open-cellular networks, with numerous potential applications in areas such as sensing and photovoltaics.

 

 

 

http://dx.doi.org/10.1039/b914136g

The development of atomic force microscopy (AFM) over the past 20 years has had a major impact on materials science, surface science and various areas of biology, and it is now a routine imaging tool for the structural characterization of surfaces. The lateral resolution in AFM is governed by the shape of the tip and the geometry of the apex at the end of the tip. Conventional microfabrication routes result in pyramid-shaped tips, and the radius of curvature at the apex is typically less than 10 nm. As well as producing smaller tips, AFM researchers want to develop tips that last longer, provide faithful representations of complex surface topographies, and are mechanically non-invasive. Carbon nanotubes have demonstrated considerable potential as AFM tips but they are still not widely adopted. This review traces the history of carbon nanotube tips for AFM, the applications of these tips and research to improve their performance.

 

http://dx.doi.org/10.1038/nnano.2009.154

 

COVENTRY, United Kingdom--(BUSINESS WIRE)--Bruker Daltonics announced today the establishment of a long-term collaborative programme for developing both applications and fundamental instrument technology in the area of extreme resolution mass spectrometry.

Building on over 14 years of experience in high performance mass spectrometry at the Department of Chemistry at Warwick, the University’s recent acquisition of both the new Bruker solariX™ 12 Tesla FTMS system and the maXis™ UHR-TOF system again puts the department at the forefront of technology for high performance mass spectrometry. At the core of the new instruments are dramatic improvements, up to an order of magnitude, in previous performance standards. These advances help address the University’s most challenging analyses including very complex mixtures in applications such as chemistry, medicinal discovery, protein interactions and petroleomics.

The collaboration is unusual in that it embraces not only topical applications innovation but also fundamental instrument development, the latter headed by Warwick Professor Peter O’Connor, who recently arrived from Boston University, and is one of the world’s most accomplished FTMS instrument development scientists. “We are very excited to be able to benefit from Peter’s ideas, and have arranged a technical fast-track for his developments to appear in our FTMS products,” commented Dr. Michael Schubert, Executive Vice President for R&D at Bruker Daltonics.

Professor Peter Sadler, Head of Chemistry at the University, whose research interests focus on metals in biology and medicine, the design and mechanism of action of metallodrugs, especially the role of proteins in metal-induced signal transduction said: “In my field state-of-the-art analysis of metal speciation holds the key to major breakthroughs in understanding both how metal ions control natural biological processes, and how metal complexes can be designed as novel therapeutic agents. Moreover, this new Bruker mass spec equipment, and the associated collaboration, will allow our newly established EPSRC Warwick Centre for Analytical Science to compete strongly at the forefront of the field.”

“We are delighted that Professors Sadler and O’Connor, who both have outstanding track records in the design and implementation of cutting-edge mass spectrometry, have chosen Bruker as a supplier and collaborative partner. It is especially gratifying to see real instrument development receiving such an energetic renewal in the UK,” commented Dr. Ian Sanders, Executive Vice President for Worldwide Sales and Marketing at Bruker Daltonics.

The solariX and maXis will be highlighted at the 18^th International Mass Spectrometry Conference (www.imsc-bremen-2009.de) in Bremen, Germany from August 30 to September 4, 2009. For more information on IMSC 2009 and related Bruker Daltonics activities, please visit www.bdal.com/imsc.

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