Analytical Methods Blog

Researchers from Central South University, Changsha, Hunan and Anyang Normal University, Anyang, Henan, China report a simple, rapid and selective colorimetric visualization of arsenic using unmodified gold nanoparticles (AuNPs) and a phytochelatin-like peptide.

The detection limit shown is 20 nM, which is lower than the World Health Organization’s (WHO) standard for drinking water, and the authors have demonstrated feasibility for the detection of arsenic in groundwater.

They say their method will be valuable for the design of new types of metal ions sensors and will likely lead to many colorimetric detection applications in environmental monitoring.

Simple, rapid and label-free colorimetric assay for arsenic based on unmodified gold nanoparticles and a phytochelatin-like peptide
Ning Xia, Yunfeng Shi, Renchun Zhang, Feng Zhao, Feng Liu and Lin Liu
Anal. Methods, 2012, Advance Article
DOI: 10.1039/C2AY25803J

Metters et al., Anal. Methods, 2012, 4, 3140-3149

Take a look at what’s HOT in the latest issue of Analytical Methods. Amongst the many articles highlighted is a paper from Editorial Board member Craig Banks of Manchester Metropolitan University. He and his group demonstrate the successful fabrication of highly novel screen printed shallow recessed electrodes comprising different electrode materials.

All the articles below will be free to access until 19 October, and don’t forget to take a look at this issue’s cover articles.

Electroanalytical properties of screen printed shallow recessed electrodes
Jonathan P. Metters, Fang Tan, Rashid O. Kadara and Craig E. Banks
Anal. Methods, 2012,4, 3140-3149
DOI: 10.1039/C2AY25512J

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Gajjar et al., Anal. Methods, 2012, Advance Article

Scientists at Lancaster University and Lancashire Teaching Hospitals NHS Trust have used infrared and Raman spectroscopy for brain tumour diagnosis.

Professor Frank Martin and colleagues used the techniques combined with statistical analysis to discriminate between normal brain tissue and three different tumour types based on the unique spectral fingerprints of their biochemical composition.

Current diagnostic approaches lack the spatial resolution required by surgeons, and delineating the excision border is important in making sure the tumour is completely removed. Vibrational spectroscopy has potential for analysing brain tissue, and Raman in particular can be performed in vivo within seconds or minutes. The information obtained by this method can be combined with conventional methods, for example immunohistochemistry, to diagnose and grade brain tumours to allow for more accurate planning and execution of surgery and/or radiation therapy. This offers more potential for individualised treatment and better long-term survival.

Professor Martin says, “These are really exciting developments which could lead to significant improvements for individual patients diagnosed with brain tumours.  We and other research teams are now working towards a sensor which can be used during brain surgery to give surgeons precise information about the tumour and tissue type that they are operating on.”

Read the article in full using the link below – it will be free to access until 8 October.

Diagnostic segregation of human brain tumours using Fourier-transform infrared and/or Raman spectroscopy coupled with discriminant analysis
Ketan Gajjar, Lara D. Heppenstall, Weiyi Pang, Katherine M. Ashton, Júlio Trevisan, Imran I. Patel, Valon Llabjani, Helen F. Stringfellow, Pierre L. Martin-Hirsch, Timothy Dawson and Francis L. Martin
Anal. Methods, 2012, Advance Article
DOI: 10.1039/C2AY25544H

Alwael et al., Anal. Methods, 2012,4, 2668-2673

There are plenty of HOT articles to take a look at in our latest issue, including one from our Editor-in-Chief, Brett Paull. His paper, with co-authors Hassan Alwael and Damian Connolly, describes a rapid, sensitive and reproducible liquid chromatographic method specifically for the quantitative determination of total free sialic acid, employing thiobarbituric acid as pre-column tagging agent, following the oxidation of sialic acid with periodic acid.

Rapid and sensitive chromatographic determination of free sialic acid in complex bio-pharma fermentation media samples
Hassan Alwael, Damian Connolly and Brett Paull
Anal. Methods, 2012,4, 2668-2673
DOI: 10.1039/C2AY25299F

Take a look at the rest of this issue’s HOT articles below – they will all be free to access until 7 September.

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This HOT article from Xiaojing Chen and co-workers of Wenzhou University, Zhejiang Province, China, looks at the analysis of enantiomeric excess. The enantiomeric forms of many compounds exert different physiological and therapeutic effects, which are an important consideration in pharmaceutical and agrochemical research, leading to large and increasing demands for single-enantiomer products.

Many existing approaches can be time-consuming and destructive, but NMR has wide applicability due to its high speed, reliable detection for quantitative and qualitative analysis. The drawback, however, is the need for an equivalent or excess amount of the chiral reagent required to give rise to signal splitting, and these reagents are usually expensive or difficult to obtain.

Here, the authors selected quinine, a commercially available and inexpensive reagent, as a chiral shift reagent to induce discrimination in the NMR spectra of enantio-isomers. They say their findings provide an accurate, rapid, and inexpensive method of determining the enantiomeric purity of amino acid derivatives, and show great potential in both peptide and pharmaceutical syntheses.

Communication: Rapid determination of enantiomeric excess of protected amino acids by catalytic amounts of chiral reagent
Xiangou Zhu, Jun Jiang, Xinxiang Lei and Xiaojing Chen
Anal. Methods, 2012, Advance Article
DOI: 10.1039/C2AY25102G

This paper will be free to access until 21 June 2012.

Zhu et al., Anal. Methods, 2012, Advance Article

Schenk et al., Anal. Methods, 2012, 4, 1252-1258

Have you seen the HOT papers in the latest issue of Analytical Methods?  Some of the interesting applications featured include analysing works of art, detection of bromate in drinking water, and extracting arsenic from rice.

There’s also a paper from Editorial Board member Ulrich Panne and colleagues (right) on the formation and aggregation of silver nanoparticles in acoustically levitated droplets investigated by simultaneous UV/Vis and Raman spectroscopy.

All these HOT papers will be free to access until 22 May.

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