Analyst Blog

The sensor detects diallylsulfides in garlic - the more diallylsulfides, the stronger the flavour

How strong is your garlic?  No, this isn’t some poor attempt at humour – the strength of garlic is a genuine concern for the food industry.

In their just-published Analyst paper, Richard Compton and his team from the University of Oxford describe an electrochemical sensor that detects the amount of diallylsulfides in garlic, compounds related to strength of flavour.

The sensor works by suspending garlic purée samples in a solution containing bromide ions. The solution is analysed voltammetrically whereby electrogenerated bromine reacts with diallylsulfides to regenerate bromide. This results in an increase in peak current, which quantifies the response.

Want to know more?  Read Elinor Richards’ news article at Chemistry World or access the paper in full below:

Towards the electrochemical quantification of the strength of garlic
Benjamin C. M. Martindale, Leigh Aldous, Neil V. Rees and Richard G. Compton
Analyst, 2011, 136, 128-133
DOI: 10.1039/C0AN00706D

But this isn’t Prof. Compton’s first foray into food analysis.  Take a look at his 2008 paper which assessed the heat of chillies:

Carbon nanotube-based electrochemical sensors for quantifying the ‘heat’ of chilli peppers: the adsorptive stripping voltammetric determination of capsaicin
Roohollah Torabi Kachoosangi, Gregory G. Wildgoose and Richard G. Compton
Analyst, 2008, 133, 888-895
DOI: 10.1039/B803588A

Hot off the press: Chemical Science paper from Analyst Editorial Board member Graham Cooks:

Accelerated bimolecular reactions in microdroplets studied by desorption electrospray ionization mass spectrometry
Marion Girod, Encarnacion Moyano, Dahlia I. Campbell and R. Graham Cooks
Chem. Sci., 2011, Advance Article
DOI: 10.1039/C0SC00416B, Edge Article

A sensor to be injected into the skin just like a tattoo that measures sodium concentrations in the blood has been developed by Heather Clark from Northeastern University and colleagues.

The sensor falls off after seven days, like a non-permanent tattoo.

To find out more about how plastic nanobeads and fluorescence have been used in this way, read Fran Burgoyne’s news article at Highlights in Chemical Biology or click below to access the Integrative Biology article in full for free.

In vivo sodium concentration continuously monitored with fluorescent sensors
J. Matthew Dubach, Edward Lim, Ning Zhang, Kevin P. Francis and Heather Clark, Integr. Biol., 2011
DOI: 10.1039/c0ib00020e

Gastric cancer is one of the leading causes of cancer-associated death in the world.

Zhiwei Huang and colleagues at the National University of Singapore and National University Hospital have developed a technique that could be used to distinguish between benign and malignant ulcers in the stomach.
The method employs an endoscopy probe that analyses tissue using Raman spectroscopy.

Want to know more?

Read Harriet Brewerton’s news article at Highlights in Chemical Biology or access the full article using the link below:

Raman endoscopy for in vivo differentiation between benign and malignant ulcers in the stomach
Mads Sylvest Bergholt, Wei Zheng, Kan Lin, Khek Yu Ho, Ming Teh, Khay Guan Yeoh, Jimmy Bok Yan So and Zhiwei Huang
Analyst, 2010, 135, 3162
DOI: 10.1039/c0an00336k

The 'nose' uses differential sensing, a form of molecular recognition, to recognise subtle structural differences between the molecules.

Stefan Matile and colleagues from the University of Geneva have created a system that mimics the way the human nose recognises scents.

Read Will Dennis’ news story at Highlights in Chemical Technology and read the full article in Chemical Science.

Pattern generation with synthetic sensing systems in lipid bilayer membranes
Toshihide Takeuchi, Javier Montenegro, Andreas Hennig and Stefan Matile, Chem. Sci., 2010
DOI: 10.1039/c0sc00386g

Fast extraction and dilution flow injection mass spectrometry (FED-FI-MS)

Sergio C. Nanita proposes an improved, simple and rapid method based on flow injection MS/MS for quantitative multiresidue screening in complex matrices.

High-throughput chemical residue analysis by fast extraction and dilution flow injection mass spectrometry
Sergio C. Nanita
Analyst, 2011, Advance Article
DOI: 10.1039/C0AN00720J, Communication

Arabinda Mallick and colleagues describe a new fully reversible dual channel optical sensor with extraordinary selectivity for fluoride and hydrogen sulfate ions.  Read the communication in full:

Norharmane: Old yet highly selective dual channel ratiometric fluoride and hydrogen sulfate ion sensor
Arabinda Mallick, Tetsuro Katayama, Yukihide Ishibasi, Masakazu Yasuda and Hiroshi Miyasaka
Analyst, 2011, Advance Article
DOI: 10.1039/C0AN00650E