Analyst Blog

An immunosensor that recognises the specific immune response to gluten, generated by coeliac disease sufferers, has been developed by scientists in Spain and Portugal.

Coeliac disease is a chronic intolerance to gluten – a protein found in wheat, barley, rye and oats – that leads to inflammation of the small intestine. This can cause malnutrition and diarrhoea in sufferers.

To read the full article please visit Chemistry World.

An electrochemical deamidated gliadin antibody immunosensor for celiac disease clinical diagnosis
Marta M. P. S. Neves ,  María Begoña González-García ,  Henri P. A. Nouws and Agustín Costa-García
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN36728B

Currently the only way to identify whether a suspicious lump is something to be concerned about is to have it removed surgically and then examined by histological review. But a new diagnostic technique based around Raman spectroscopy could provide a faster diagnosis without the need for such invasive procedures.

Raman Spectroscopy has been used previously to distinguish benign and metastatic axillary lymph nodes (in the breast) and mediastinal nodes (in the oesophagus). Now Nicholas Stone and co-workers at the University of Exeter, UK have now applied the technique to distinguish between different cancerous conditions of lymph nodes in the head and neck.

Doctors coudl soon be using Raman spectroscopy to peform 'optical biopsies' of tumours © Shutterstock

 To read the full article please visit Chemistry World.

Discrimination between benign, primary and secondary malignancies in lymph nodes from the head and neck utilising Raman spectroscopy and multivariate analysis
Gavin Rhys Lloyd, Linda E. Orr, Jonathan Christie-Brown, Keith McCarthy, Simon Rose, Michael Thomas and Nicholas Stone
Analyst, 2013, Advance Article
DOI: 10.1039/C2AN36579K

Antibiotics are used regularly for treating bacterial infections, but there is currently no quick and simple test to determine the most effective type or dose of antibiotic for a specific patient infection. As a result, it’s estimated that around 30% of all antibiotic prescriptions are not the optimum choice. This can lead to the formation of drug-resistant bacteria, delayed recovery, and in some cases death from an infection.

Tests for the most appropriate antibiotic choice are performed for life-threatening patient infections. However, microbes have to be grown on agar plates from a very small patient sample which delays results for a few days. Hiroaki Suzuki et al have designed a microfluidic device that is able to determine the most effective antibiotic treatment in just 12 hours.

To read the full article please visit Chemistry World.

A microfluidic microbial culture device for rapid determination of the minimum inhibitory concentration of antibiotics
Rika Takagi ,  Junji Fukuda ,  Keiji Nagata ,  Yutaka Yawata ,  Nobuhiko Nomura and Hiroaki Suzuki
Analyst, 2013,138, 1000-1003
DOI: 10.1039/C2AN36323B

Robin McCarley is professor of chemistry at Louisiana State University, US. His research spans liposome systems, surface chemistry, polymer chemistry, nanoscience and bioanalytical/physical chemistry. His current interests are in stimuli-responsive materials in solution and on surfaces, and modified polymers for use in lab-on-a-chip technologies.

You work on bioanalytical sensors – why is this an exciting area of research?

Robin McCarley

It’s really a nexus region where you bring together people from so many different, diverse areas of training and background. That to me is exciting because I think that’s the way we’ll solve a lot of scientific problems in the future. No one principal investigator can attack problems by themselves anymore – you need to have an integrated knowledge base. At the same time, the challenges are all over the map: food, human health and environment. It’s amazing to consider the cross-cutting nature of research right now.

To read the full article please visit Chemistry World.

Scientists in Denmark have designed a new sensor to detect cells that over-express folate receptors, including cancer cells. Jaime Castillo-León from the Technical University of Denmark and colleagues’ sensor consists of an electrochemical platform composed of graphene and peptide nanotubes with folic acid.

Cancer cells have a high requirement for folic acid as it is necessary for their metabolism, so the cells have 500 times more folate receptors compared with a healthy cell, explains Castillo-León. The receptors are like antennas on the surface of the cell membrane that seek out folic acid. The cancer cells interact with the electrochemical platform, resulting in a decrease in the current being measured. The sensor allows the detection of cancer cells at a concentration as low as 250 cells per millilitre.

The nanotube–folic acid modified graphene electrode; the interaction between folic acid and folate receptors on HeLa cells

 To read the full article visit Chemistry World

Detection of cancer cells using a peptide nanotube–folic acid modified graphene electrode
John J. Castillo, Winnie E. Svendsen, Noemi Rozlosnik, Patricia Escobar, Fernando Martínez and Jaime Castillo-León
Analyst, 2013, Advance Article
DOI: 10.1039/C2AN36121C

UK scientists have used mass spectroscopy to determine the sex of a perpetrator from the peptides in fingerprints left at a crime scene.

Peptides naturally present in sweat and their relative abundance are distinctive for one sex or the other. © Shutterstock

Simona Francese from Sheffield Hallam University explains that peptides naturally present in sweat and their relative abundance are distinctive for one sex or the other. Francese and her team used matrix assisted laser desorption ionisation mass spectrometry to detect the peptides and their relative abundance from fingerprint samples. ‘Results can be obtained in 10 minutes from sample preparation to data acquisition and analysis with 85% accuracy,’ says Francese.

To read the full article visit Chemistry World

Direct detection of peptides and small proteins in fingermarks and determination of sex by MALDI mass spectrometry profiling
Leesa Susanne Ferguson, Florian Wulfert, Rosalind Wolstenholme, Judith Marlou Fonville, Malcolm Ronald Clench, Vikki Amanda Carolan and Simona Francese
Analyst, 2012,137, 4686-4692
DOI: 10.1039/C2AN36074H