Analyst Blog

Bi et al., Analyst, 2013, Advance Article

Interlocking molecular structures known as rotaxanes have been expanded to DNA to create a new class of nanomachines for studying biological systems. Li Li and researchers at Qingdao University used DNA psuedorotaxnes as an alternative method for detecting low concentrations of mRNA in cancerous cell lines. Instead of the traditional polymerase chain reaction, a cross-rolling circular amplification synthesizes and links two DNA psuedorotaxnes into a single DNA rotaxane, which contains a biotinylated primer detected by a streptavidin coated magnetic nanoparticle. To read more about the zeptomole sensitivity and high selectivity accomplished by this assay, check out the article below.

Ultrasensitive detection of mRNA extracted from cancerous cells achieved by DNA rotaxane-based cross-rolling circle amplification
Sai Bi, Yangyang Cui and Li Li
Analyst, 2013, Advance Article
DOI: 10.1039/C2AN36118C

Sulé-Suso et al., Analyst, 2013, Advance Article

By Jennifer A. Dougan, Imperial College London, Web Writer

Lung cancer has a poor survival rate worldwide and research to better diagnose and manage the disease is of paramount importance.  Recent work by Josep Sulé-Suso’s group from the Institute for Science and Technology in Medicine, based at Keele University attempts to improve our understanding of the behaviour of lung cancer.  The approach taken by the group and a collaborator from the J. Heyrovský Institute of Physical Chemistry in the Czech Republic, was to analyse the volatile components (VCs) excreted from lung cancer cells and compare those to healthy lung cells using Selected Ion Flow Tube Mass Spectrometry, SIFT-MS.  However, rather than analysing the headspace produced from a 2D growth of cells, the researchers aimed to mimic more closely the in vivo conditions by hosting the cells in a 3D hydrogel scaffold.  They found that moving from a 2D to 3D system did, indeed, have an effect on the levels of VCs for both cancerous and non-cancerous cells and that they were able to discriminate between the two cell types at some concentrations.  Although there is a way to go before SIFT-MS analysis reaches its ultimate aim; the analysis, diagnosis and management of lung cancer from patient exhalations, its ability to analyse multiple compounds simultaneously in humid air samples makes it an attractive technique for further studies.  To read more about this HOT new Analyst article click below, it will be free to read until Dec 6th.

Quantification by SIFT-MS of acetaldehyde released by lung cells in a 3D model
Abigail V. Rutter, Thomas W. E. Chippendale, Ying Yang, Patrik Španěl, David Smith and Josep Sulé-Suso
Analyst, 2013, Advance Article
DOI: 10.1039/C2AN36185J

Take a look below at some wonderful HOT articles we’ve recently published this month in Analyst. There are papers covering a variety of fields, including point of care devices, microfluidics and biosensors. These HOT papers will be free to read until Dec 5th.

Gravitational field-flow fractionation integrated with chemiluminescence detection for a self-standing point-of-care compact device in bioanalysis
S. Casolari ,  B. Roda ,  M. Mirasoli ,  M. Zangheri ,  D. Patrono ,  P. Reschiglian and A. Roda
Analyst, 2013, Advance Article
DOI: 10.1039/C2AN36041A 
 
Integration of multiple components in polystyrene-based microfluidic devices part I: fabrication and characterization
Alicia S. Johnson ,  Kari B. Anderson ,  Stephen T. Halpin ,  Douglas C. Kirkpatrick ,  Dana M. Spence and R. Scott Martin
Analyst, 2013, Advance Article
DOI: 10.1039/C2AN36168J 
 
Integration of multiple components in polystyrene-based microfluidic devices part II: cellular analysis
Kari B. Anderson ,  Stephen T. Halpin ,  Alicia S. Johnson ,  R. Scott Martin and Dana M. Spence
Analyst, 2013, Advance Article
DOI: 10.1039/C2AN36171J 
 
A biosensor fabricated by incorporation of a redox mediator into a carbon nanotube/nafion composite for tyrosinase immobilization: detection of matairesinol, an endocrine disruptor
Jahangir Ahmad Rather ,  Sanaz Pilehvar and Karolien De Wael
Analyst, 2013, Advance Article
DOI: 10.1039/C2AN35959F

As well as our two front covers, we have a number of additional HOT papers in this issue of Analyst. Take a look at some of the hot science that we have published in this latest issue.

These papers will be free to read until Nov 30th.

Highlighting a need to distinguish cell cycle signatures from cellular responses to chemotherapeutics in SR-FTIR spectroscopy
C. Hughes, M. D. Brown, F. J. Ball, G. Monjardez, N. W. Clarke, K. R. Flower and P. Gardner
Analyst, 2012, 137, 5736-5742
DOI: 10.1039/C2AN35633C

A simplified electrospray ionization source based on electrostatic field induction for mass spectrometric analysis of droplet samples
Xiaohui Lu, Hong Chen, Xiang Li, Jianmin Chen and Xin Yang
Analyst, 2012, 137, 5743-5748
DOI: 10.1039/C2AN35909J

A bacteriophage endolysin-based electrochemical impedance biosensor for the rapid detection of Listeria cells
Mona Tolba, Minhaz Uddin Ahmed, Chaker Tlili, Fritz Eichenseher, Martin J. Loessner and Mohammed Zourob
Analyst, 2012, 137, 5749-5756
DOI: 10.1039/C2AN35988J

In situ noninvasive Raman microspectroscopic investigation of polychrome plasterworks in the Alhambra
Ana Dominguez-Vidal, Maria Jose de la Torre-Lopez, Ramon Rubio-Domene and Maria Jose Ayora-Cañada
Analyst, 2012, 137, 5763-5769
DOI: 10.1039/C2AN36027F

Wang et al., Analyst, 2013, Advance Article

Detection for the real world demands simplicity, cost-effectiveness, accuracy, durability, and high performance. The latest advancement in electrochemical sensing is looking very optimistic (quite literally, see picture). Joseph Wang from the University of California San Diego, USA and his colleagues have developed new tattoo-based solid-contact ion-selective electrodes (ISE) for monitoring pH of the skin. This technology makes use of commercially available temporary transfer tattoo paper, standard screen printing and solid contact polymer ISE methods. Find out more about this discovery by accessing the link below, it will be free to read until Nov 28th:

Tattoo-based potentiometric ion-selective sensors for epidermal pH monitoring
Amay J. Bandodkar, Vinci W. S. Hung, Wenzhao Jia, Gabriela Valdés-Ramírez, Joshua R. Windmiller, Alexandra G. Martinez, Julian Ramírez, Garrett Chan, Kagan Kerman and Joseph Wang
Analyst, 2013, Advance Article
DOI: 10.1039/C2AN36422K

By Polly-Anna Ashford, Web Writer

Mao et al., Analyst, 2013, Advance Article

The study of neurochemistry offers a powerful insight into the mechanisms and molecules responsible for brain function. Lanqun Mao and co-workers at the Chinese Academy of Sciences, Beijing, have developed a simple approach towards the continuous monitoring of glucose in the brain of a living rat. Their technique couples in vivo microdialysis with biofuel cell technology, using a self-powered biogenerator as the detector for neurochemical sensing. This method is shown to be highly specific for the analyte of choice, with no interference from other chemicals commonly present such as dopamine or uric acid. Biofuel cells are of particular interest to scientists because they harness the energy produced by biochemical reactions in living systems. As this report shows, their use in biosensing opens up the potential for greater investigation of brain function at the molecular level. This paper will be free to read until Nov 28th.

Biofuel cell-based self-powered biogenerators for online continuous monitoring of neurochemicals in rat brain
Hanjun Cheng, Ping Yu, Xulin Lu, Yuqing Lin, Takeo Ohsaka and Lanqun Mao
Analyst, 2013, Advance Article
DOI: 10.1039/C2AN36385B

Mallik et al., Analyst, 2012, 137, 5487

By Jennifer A. Dougan, Imperial College London, Web Writer

Sanku Mallik and co-workers from North Dakota State University have developed a method for the post-translational discrimination of breast cancer cell sub-types. The researchers have achieved this by use of water soluble fluorescent polymers which are designed to interact with proteins, enzymes and amino acids. The fluorescence spectra from the polymers when exposed to the conditioned culture media of different cells lines were subject to linear discriminant analysis and used to discriminate between four cell lines and between breast cancer and other tissue types. Although the particular proteins or other biomolecular species and interactions responsible for the spectral changes have not yet been elucidated, this report is an interesting post-translational alternative to standard molecular biology techniques. This paper will be free to read until Nov 20th.

Fluorescent polymer-based post-translational differentiation and subtyping of breast cancer cells
Michael D. Scott, Rinku Dutta, Manas K. Haldar, Anil Wagh, Thomas R. Gustad, Benedict Law, Daniel L. Friesner and Sanku Mallik
Analyst, 2012, 137, 5487-5490
DOI: 10.1039/C2AN35877H

Qu et al., Analyst, 2012, 137, 5483

Trying to incorporate quantum dots into biological systems has proven difficult due to their lack of biocompatibility and the toxicity of heavy metals inside cells. Recently developed carbon nanodots retain the advantages of quantum dots, but can function in biological media. Xianogang Qu and researchers at the Chinese Academy of Sciences incorporated carbon nanodots in a thrombin detection assay using DNA aptamers. Thrombin contains two binding sites that are recognized by different aptamers on both a silica nanoparticle and carbon nanodot. The multi-binding site capabilities of aptamers allow for greater sensitivity when compared to single site antibodies, and the fluorescent signal of the carbon nanodot is only detected when bound to thrombin on the silica nanoparticle. Click on the paper below to read more, it will be free to read until November 16th.

Aptamer carbon nanodot sandwich used for fluorescent detection of protein
Bailu Xu, Chuanqi Zhao, Weili Wei, Jinsong Ren, Daisuke Miyoshi, Naoki Sugimoto and Xiaogang Qu
Analyst, 2012, 137, 5483-5486
DOI: 10.1039/C2AN36174D

Zourob et al., Analyst, 2012, Advance Article

By Polly-Anna Ashford, Web Writer

First discovered in the 1920s, Listeria remains a prolific food and water borne bacteria with a significant mortality rate. Scientists led by Mohammed Zourob at the National Institute of Scientific Research (INRS), Quebec, in collaboration with ETH Zürich, have developed a new screen printed gold electrode for the specific detection of Listeria via electrochemical impedance spectroscopy (EIS). Current methods of detection using culturing techniques are time-consuming and difficult to automate. In this Analyst paper, the authors report the immobilisation of endolysin protein onto a gold surface, which is characterised and monitored using the simple, low cost EIS technique. This method allows the rapid detection of Listeria in either pure culture or samples of artificially contaminated milk.

A bacteriophage endolysin-based electrochemical impedance biosensor for the rapid detection of Listeria cells
Mona Tolba, Minhaz Uddin Ahmed, Chaker Tlili, Fritz Eichenseher, Martin J. Loessner and Mohammed Zourob
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN35988J