High Sensitivity Using Low Cost Equipment

Laura Ruvuna is guest web writer for Analyst. She is currently a PhD student at Northwestern University, Evanston, Illinois, USA.

Low cost webcam based prism spectrometer

Techniques such as cavity ring-down spectroscopy (CRDS) have greatly enhanced the sensitivity in traditional absorption spectroscopy methods. Although CRDS can detect analytes in very small concentrations in solution, it requires expensive and complex instrumentation, which has restricted its widespread implementation. Alternatively, broadband cavity enhanced absorption spectroscopy (BBCEAS) has emerged to overcome some of these limitations. These adjustments allow for multiplexed data collection and improved resolution.

Researchers at the University of Cambridge, UK,  have constructed a BBCEAS apparatus using relatively simple components and achieved sensitivity levels similar to much more expensive systems.  Using a well-studied process, the Griess Assay, they measured different concentrations of nitrite and the dye Rhodamine 6 G with a system that contained a low cost prism spectrometer and a webcam detector. The limits of detection were found to be 3.7 nM (nitrite) and 850 pM (Rhodamine), and by adding a better detector, these can further be improved upon.

To read the full article, please access the link below. This paper will be free to read for the next three weeks:

High sensitivity liquid phase measurements using broadband cavity enhanced absorption spectroscopy (BBCEAS) featuring a low cost webcam based prism spectrometer
Zhechao Qu, Julia Engstrom, Donald Wong, Meez Islam and   Clemens F. Kaminski
Analyst, 2013,138, 6372-6379
DOI: 10.1039/C3AN01441J

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IEEE Nanotechnology Council Meeting: Nanoengineered Biomedical Devices

Learn. Share. Network.

Annual Fall Meeting IEEE Nanotechnology Council of the SF Bay Area

Tuesday, 19 November 2013 – Santa Clara, CA

Nanoengineered Biomedical Devices

Registration and poster abstract submission here

Join colleagues from industry and academia to learn about frontiers of nanotechnology for medical devices, diagnostics, and biomedical research. This one-day symposium will include internationally recognized speakers, a student poster session, and time for discussions and networking.

Confirmed speakers:

David Deamer, UC Santa Cruz

Erkin Seker, UC Davis

Demir Akin, Stanford School of Medicine

Adam Seger, MagArray, Inc

Mehdi Javanmard, Stanford Genome Tech Ctr

Tom Peyser, Dexcom Inc

Dominik Ziegler, Lawrence-Berkeley & Scubaprobe Inc

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Analyst Poster Prize: ICAVS-7 Conference, Kobe, Japan

Analyst Poster Prize: ICAVS-7 Conference, Kobe, Japan

We are please to announce that the Analyst Poster Prize from the recent ICAVS-7 Conference held in August 2013 in Kobe, Japan has been awarded to Cosima Koch.

Congratulations to Cosima for her winning poster!

Cosima is currently pursuing a PhD in Analytical Chemistry at Vienna University of Technology focusing on the development of a new technology for infrared spectroscopy of particles in suspension. For the first time, acquisition of spectra of suspended particles is possible through the combination of ultrasonic particle manipulation and attentuated total reflection Fourier transform IR (ATR FTIR) spectroscopy. During the first part of her PhD, she helped with the design and construction of an ultrasound accessory for a commercially available inline fiber optic ATR probe. Recently, in a collaboration with the bioprocess technology department, the first spectra of S. cerevisiae (baker’s yeast) during fermentation were recorded in situ in a bioreactor with this prototype probe. The techniques allows to gain insight into biochemical changes in the cells in real time without the need for sampling. Apart from investigating the biochemical composition of cells during a fermentation and offline by FTIR and Raman microspectroscopy, Cosima investigates the use of ATR FTIR spectroscopy and chemometrics for monitoring media components and bioproducts to control bioprocesses.

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Intracellular enzymatic activity by SERRS

Jennifer A. Dougan is a guest web-writer for Analyst. She is currently a Post-Doctoral Research Associate at Imperial College London, UK.

Analysis of intracellular enzyme activity by SERS

Enzymatic activity in cells has been revealed by surface enhanced Raman scattering (SERRS) spectroscopic studies, according to new research led by Duncan Graham at the University of Strathclyde.

X-Gal, a SERRS inactive precursor and a common marker for galactosidase enzymes, was introduced to macrophage cells along with metal nanoparticles. On incubation, enzymatic activity of galactosidase on X-Gal produces a SERRS active trans-alkene dimerised product. This product adsorbs onto the delivered citrate capped gold nanoparticles producing a distinctive SERRS signal. Using SERRS mapping to evaluate the formation of this product, enzyme activity was assessed, not only across a cell population, but also at sub-cellular levels. The authors note that the SERRS activity in this study may not reflect the only sites of galactosidase activity, but rather the sites where both galactosidase and the nanoparticles are co-located. Nevertheless, approaches towards sub-cellular analysis of enzyme activity are important.

Advances in targeted nanoparticle uptake combined with the multiplexing capability of SERRS make this an interesting approach to sub-cellular studies of biochemical activity.

To read the full article, please click on the link below. This paper will be free to read until October 18th.

Analysis of intracellular enzyme activity by surface enhanced Raman scattering
Ross Stevenson, Sarah McAughtrie, Laura Senior, Robert J. Stokes, Helen McGachy, Laurence Tetley, Paola Nativo, James M. Brewer, James Alexander, Karen Faulds and   Duncan Graham
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN00729D

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HOT Articles in Analyst

Take a look at these new HOT articles just published in Analyst! These papers will be free to read for the next three weeks. Download them today!

The global identification of tRNA isoacceptors by targeted tandem mass spectrometry
Collin Wetzel and Patrick A. Limbach  
Analyst, 2013,138, 6063-6072
DOI: 10.1039/C3AN01224G

Extraction and separation of proteins by ionic liquid aqueous two-phase system
Xiao Lin, Yuzhi Wang, Qun Zeng, Xueqin Ding and Jing Chen  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01301D

A smart T1-weighted MRI contrast agent for uranyl cations based on a DNAzyme–gadolinium conjugate
Weichen Xu, Hang Xing and Yi Lu  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01182H

Improved analysis of oligosaccharides for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using aminopyrazine as a derivatization reagent and a co-matrix
Yan Cai, Ying Zhang, Pengyuan Yang and Haojie Lu
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01228J

A chemical quenching- and physical blocking-based method to minimize process-mediated aggregation of antibody-crosslinked nanoparticles for imaging application
Chandra K. Dixit, Shibsekhar Roy, Conor Byrne, Richard O’Kennedy and Colette McDonagh  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01294H

Exploring the electrochemical performance of graphitic paste electrodes: graphene vs. graphite
Luiz C. S. Figueiredo-Filho, Dale A. C. Brownson, Maria Gómez-Mingot, Jesús Iniesta, Orlando Fatibello-Filho and Craig E. Banks  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN00950E

An investigation into the simultaneous enzymatic and SERRS properties of silver nanoparticles
Kristy S. McKeating, Sian Sloan-Dennison, Duncan Graham and Karen Faulds  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01451G

Electrochemical piezoelectric-excited millimeter-sized cantilever (ePEMC) for simultaneous dual transduction biosensing
Blake N. Johnson and Raj Mutharasan  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01353G

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Bacteria incriminated by their odour

Researchers in Taiwan and the US have developed a device that uses the volatile organic compounds released by bacteria to identify the bacteria as they are cultured. When fully developed, this single-step gadget could trump the speed of current clinical techniques.

Sepsis and other bloodstream infections are very dangerous and need immediate treatment. It is therefore essential to detect microorganisms in human blood quickly to decide the most effective treatment.

Blood cultures are currently used to detect if bacteria are present in a patient’s blood. This takes 24 hours or more just to reveal if a sample contains bacteria. Further tests reveal the identity of the bacteria and show which antibiotics can kill them. This multi-step process can take several days, and in the meantime patients are often treated with antibiotics presumptively, which can induce side effects in the patient as well as antibiotic resistance in the bacteria.

Chemometric analysis of colour changes reveals which strain of bacteria is present

 To read the full article, please visit Chemistry World.

Single step, rapid identification of pathogenic microorganisms in a culture bottle
Yu W. Chu, Bo Y. Wang, David A. Engebretson and James R. Carey  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01175E

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A biochemical eyewitness

Blood found at a crime scene could give police an indication of a criminal suspect’s ethnicity there and then thanks to a new bioassay.

Biological samples recovered at crime scenes can provide vital evidence to identify, accuse and exonerate. DNA/RNA analysis techniques for profiling suspects are sophisticated, but usually require complex equipment. On-site analysis of fluids is mostly limited to simple identification of possible samples, such as bloodstains, which are then collected and transported to specialist laboratories. This creates undesirable delays for investigations, where time is often of the essence.

To read the full article, please visit Chemistry World.

Biocatalytic analysis of biomarkers for forensic identification of ethnicity between Caucasian and African American groups
Friederike Kramer, Lenka Halámková, Arshak Poghossian, Michael J. Schöning, Evgeny Katz and Jan Halámek  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01062G

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HOT Articles in Analyst

Take a look at these new HOT articles just published in Analyst! These papers will be free to read for the next two weeks. Click on the links below:

A new turn-on fluorescent chemosensor based on diketopyrrolopyrrole (DPP) for imaging Zn2+ in living cells
Guanjun Zhang, Haiying Li, Shiming Bi, Longfeng Song, Yunxiang Lu, Liang Zhang, Jianjun Yu and Limin Wang  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN00873H

Separation of metalloproteins using a novel metal ion contaminant sweeping technique and detection of protein-bound copper by a metal ion probe in polyacrylamide gel electrophoresis: distribution of copper in human serum
Shingo Saito, Mitsuyoshi Kawashima, Hiroki Ohshima, Kazuki Enomoto, Makoto Sato, Hajime Yoshimura, Keitaro Yoshimoto, Mizuo Maedad and Masami Shibukawaa  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01107K

High pressure nanoelectrospray ionization mass spectrometry for analysis of aqueous solutions
Md. Matiur Rahman, Mridul Kanti Mandal, Kenzo Hiraoka and Lee Chuin Chen 
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN00699A

Introducing novel amorphous carbon nanoparticles as energy acceptors into a chemiluminescence resonance energy transfer immunoassay system
Zhenxing Wang, Hongfei Gao and Zhifeng Fu 
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01177A

The global identification of tRNA isoacceptors by targeted tandem mass spectrometry
Collin Wetzel and Patrick A. Limbach 
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01224G

Enhanced imaging of developed fingerprints using mass spectrometry imaging
M. J. Bailey, M. Ismail, S. Bleay, N. Bright, M. Levin Elad, Y. Cohen, B. Geller, D. Everson, C. Costa, R. P. Webb, J. F. Watts and M. de Puit  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01204B

Photonic crystal enhanced microscopy for imaging of live cell adhesion
Weili Chen, Kenneth D. Long, Meng Lu, Vikram Chaudhery, Hojeong Yu, Ji Sun Choi, James Polans, Yue Zhuo, Brendan A. C. Harley and   Brian T. Cunningham  
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01541F

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Advances in GC IV, Cheshire

Advances in GC IV
30th October 2013 (First Announcement)
LGC Ltd, The Heath Business Park, Runcorn, Cheshire

Joint meeting organised by The Chromatographic Society and the North West Region of the Analytical Division of the Royal Society of Chemistry.

After the success of the 2011 meeting we are pleased to announce another follow up meeting in the series.
GC is still technique of choice for analysing both volatile and semi volatile compounds, but as we move to more difficult matrices, more is being asked of the technique in terms of separation and limits of detection. The meeting sets out to both give an overview of current GC technologies and methodologies, information on newer detection/separation solutions and case studies from all the main user areas.
 
In parallel to the full meeting program will be an Instrument exhibition with representatives from all the major GC Instrument and Consumables Suppliers.
 
For more information please contact Alan Handley.
Tel 01928 513681

Mobile 07917416529
E-mail: alan.handley@lgcgroup.com
 
Advances in GC IV – Topics and Speakers

09:15- 09:50        Registration ,Coffee and Exhibition
 
09:50-10:00         Opening and Welcome
                              Alan Handley (LGC Ltd)
 
10:00-10:40         Sample Preparation solutions for Gas Chromatography
                               Ray Perkins (Anatune)
 
10:40-11:20         Column Selection – there more to life than a boiling point column
                               Jaap de Zeeuw (Restek)
                                               
11:20 –12:00       Demystifying Comprehensive GC
                               Prof Jean-Francois Focant (University of Liege)
 
Exhibition and Lunch
 
14:00 -14:40        A fresh approach to managing GC in your Laboratory
                               Greg Johnson (Thermo Fisher)
 
14:40 – 15:20       Exploring the extra dimension – Getting more out of your GC Analysis
                                Ken Brady (Agilent)
 
15:20 – 15:35       Coffee
 
15:35 – 16:05       What has Deconvolution ever done for us?
                                Neil Owen (Givaudan UK Ltd)
                                                               
16:05 – 16:35       Are GC techniques comparable to the human nose?
                                Lewis Jones (Mars Waltham)
 
16:35                     Close of meeting
 
Registration (Includes all sessions, exhibition and lunch)
 
Members of either The Chromatographic Society, RSC or BMSS                 £60
 
Non Members                                                                                                          £80
 
Students* and Retired                                                                                            £10
*Student bursaries for travel are available please contact Alan Handley

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A Competitive Binding Scheme for Cancer Cells

Laura Ruvuna is guest web writer for Analyst. She is currently a PhD student at Northwestern University, Evanston, Illinois, USA.

Ultrasensitive electrochemical detection of leukemia cells

Detecting cancerous cells, such as those of leukemia, in early stages can greatly affect patient treatment and survival. Current diagnostic tools such as immunohistochemistry require large concentrations of cells, which occur in advanced stages of the disease.

Jun-Jie Zhu and co-workers at Nanjing University , China, developed an assay for leukemia cells using aptamers in a unique, competition-based electrochemical sensor. This involves the use of magnetic (Fe3O4) and gold nanoparticles and the detection of electrochemical signals from deposited silver nanoparticles using square wave anodic stripping voltammetery. The gold nanoparticles bind to the much larger magnetic particles through an apatmer, but the apatmer has a higher specificity for the leukemia cells. Upon introduction of the cells, some of the gold nanoparticles are released from the magnetic surface affecting the amount of detectable signal from the silver. The researchers successfully detected as few as 10 cells and demonstrated a high specificity of the aptamers for only one type of leukemia cells. Although they chose leukemia cells, the only limitation is the specificity of aptamers available and ideally, any cancer could be tested for in this system.

To read the full article, please access the link below. This paper will be free to read for the next three weeks.

A novel aptamer-based competition strategy for ultrasensitive electrochemical detection of leukemia cells
Kui Zhang, Tingting Tan, Jia-Ju Fu, Tingting Zheng and   Jun-Jie Zhu
Analyst, 2013, Advance Article
DOI: 10.1039/C3AN01255G

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