Analyst Blog

On exposure to water, the "soaking" action of the polymer is analogous to the behaviour of a sponge.

This paper explains why the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), regularly used for the preparation of solid-contact ion-selective electrodes, does not show evidence for a water layer.  One of the referees commented that ‘this manuscript clarifies an issue that has been puzzling me for a few years now.’  These findings will aid those working in the chemical sensors community by helping to understand the physical state of the polymer layers in solid-contact ion-selective electrodes when they are exposed to solutions.

Read the paper for free until 17th August.

Water uptake in the hydrophilic poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) solid-contact of all-solid-state polymeric ion-selective electrodes
Jean-Pierre Veder, Roland De Marco, Graeme Clarke, San Ping Jiang, Kathryn Prince, Ernö Pretsch and Eric Bakker
Analyst
DOI: 10.1039/C1AN15267J

You might also find this Analyst paper interesting….

Tuning the gas sensing performance of single PEDOT nanowire devices
Carlos M. Hangarter, Sandra C. Hernandez, Xueing He, Nicha Chartuprayoon, Yong Ho Choa and Nosang V. Myung
Analyst, 2011, 136, 2350-2358
DOI: 10.1039/C0AN01000f

This study could help predict future bird flu outbreaks.

In this paper, a team from Sydney, combine bioinformatics and high resolution mass spectrometry to identify the strain, time period and region of avian flu hemagglutinin.

Read the paper for free until 15th August.

Evolution of H5N1 influenza virus through proteotyping of hemagglutinin with high resolution mass spectrometry
Ji-Won Ha and Kevin M. Downard
Analyst
DOI: 10.1039/C1AN15354D

Breath samples are taken up by the ventilator and sent along a sample line to the mass spectrometer

David Smith from Keele University and colleagues have developed a way of continuously analysing the breath of unconscious patients undergoing surgery using a selected ion flow tube-mass spectrometer (SIFT-MS), which enables measurements to be taken and results to be viewed in the operating theatre.

“Specific breath gases can be monitored that can indicate to the surgeon and anaesthetist the status of the patient, thus allowing more informed decision making and improve the outcome of the surgical procedure,” says Smith.

Read Holly Sheahan’s news story in Chemistry World, and access the communication for free below:

Communication: On-line, real time monitoring of exhaled trace gases by SIFT-MS in the perioperative setting: a feasibility study
Piers R. Boshier, Julia R. Cushnir, Vikash Mistry, Alison Knaggs, Patrik Španěl, David Smith and George B. Hanna
Analyst, 2011, Advance Article
DOI: 10.1039/C1AN15356K

Heat given off by the reaction between the substance of interest and an enzyme is used to determine the amount of that substance present.

Srinivas Tadigadapa and colleagues at Pennsylvania State University have designed a calorimetric sensor as a point-of-care diagnostic instrument that can detect low levels of glucose.

Calorimetric sensors can detect minute heat changes released during biological reactions so could be used to measure trace amounts of clinically relevant biochemicals, such as glucose and urea. But, until now, designing these sensors has been complex and unreliable and the sensors produced have not been robust enough for practical use.

To find out how this recent work overcomes some of these limitations, read Harriet Brewerton’s news article in Chemistry World, and access the paper using the link below:

Monitoring biochemical reactions using Y-cut quartz thermal sensors
Kailiang Ren, Ping Kao, Marcelo B. Pisani and Srinivas Tadigadapa
Analyst, 2011, Advance Article
DOI: 10.1039/C1AN15153C

A recent collection of Noteworthy Chemistry from the ACS featured an Analyst article from Ben Zhong Tang and co-workers at Zhejiang University, Hangzhou, China.

They prepared BSA–tetraphenylethylene derivative conjugates with aggregation-induced emission (AIE) properties that act as effective fluorescent reporters for simple, sensitive, rapid, low-cost, label-free homogeneous detection of proteases such as trypsin and the protease inhibitor α1-antitrypsin.

Anomalous or elevated physiological levels of proteases and altered α1-antitrypsin function are both implicated in several diseases.  As stated in the ACS article, “the simplicity, high sensitivity and rapidity of the BSA–tetraphenylethylene bioconjugate assay make it a prime candidate for AIE probes for biological process monitoring and cancer diagnostics.”

Read the paper by following the link below:

BSA–tetraphenylethene derivative conjugates with aggregation-induced emission properties: Fluorescent probes for label-free and homogeneous detection of protease and α1-antitrypsin
Jian-Ping Xu, Yuan Fang, Zhe-Gang Song, Ju Mei, Lan Jia, An Jun Qin, Jing Zhi Sun, Jian Ji and Ben Zhong Tang
Analyst, 2011, 136, 2315-2321
DOI: 10.1039/C0AN00813C

The sensor is worn on the wetsuit's sleeve and the potentiostat and battery are kept in a watertight compartment integrated into the wetsuit

Sensors printed onto the sleeves of wetsuits could alert the wearer to contaminated water. Navy divers could also use the sensors to locate underwater explosives, such as mines.

Joseph Wang at the University of California in San Diego, US, and colleagues have demonstrated that their sensors can be printed directly onto neoprene, a synthetic rubber commonly used in wet- and dry-suits.

Read Tamsin Phillips’ news piece in Chemistry World or access the full article for free using the link below.

Wearable electrochemical sensors for in situ analysis in marine environments
Kerstin Malzahn, Joshua Ray Windmiller, Gabriela Valdés-Ramírez, Michael J. Schöning and Joseph Wang
Analyst
DOI: 10.1039/C1AN15193B