Analyst Blog

Scientists in the US have devised an enzymatic logic system that could be used for releasing drugs. This is the first report of a man-made biomolecular system that can process a series of physiological signals, without the use of electronics.

Biocomputer-based logic systems that process biomolecular signals could revolutionise drug administration. By harnessing signal-responsive electrode surfaces that respond to biochemical signals, widespread personalised medicine takes a step closer to reality.

Historically, drug-release systems have been plagued by slow and uncontrolled release. Various external triggers, including temperature, pH and biochemical species, have been used to stimulate drug release. Systems activated by biochemical signals are often complicated and limited, combining both the receptor and the release system. Physical separation of these two components on individual electrodes would simplify the process.

Expanding on their recent work with glucose sensing electrodes, Evgeny Katz and Shay Mailloux at Clarkson University, in collaboration with Jan Halámek from the State University of New York at Albany, have developed a logical biomolecule release system. An electrode covered by a redox-active, iron(III)-cross-linked alginate polymer film with physically entrapped biomolecules serves as the substance-releasing component and a pyrroloquinoline quinone (PQQ)-modified electrode serves as the biocatalytic electrode.

To read the full article, please visit Chemistry World

A model system for targeted drug release triggered by biomolecular signals logically processed through enzyme logic networks
Shay Mailloux, Jan Halámek and Evgeny Katz
Analyst, 2014, Advance Article
DOI: 10.1039/C3AN02162A, Communication

What discoveries caused the biggest buzz in chemistry labs in 2013? With the help of an expert panel of journal editors Chemistry World reviews the ground breaking research and important trends in this year’s crop of chemical science papers.

Find out which Analyst articles have been featured in Chemistry World this year:

Crime scene chemistry

Improvements in forensic techniques have also featured on our pages this year. A team in the US developed a device that investigators can wear on their fingertips to rapidly identify traces of explosives and gunshot residue. The sensor consists of an electrode screen-printed onto a stretchable sheath worn on the index finder, and a sheath for the thumb coated with a solid-state ionogel electrolyte. To analyse a sample the investigator simply squeezes their finger and thumb together after swiping a surface, completing the electrochemical cell. A portable analyser then reads the voltammetric signal, identifying distinct peaks for explosives or gunshot residue. The process takes just a few minutes, cutting down the lengthy practice of sample collection and lab analysis.

Another group has developed a bioassay that can be used to analyse blood samples on-site to give investigators an early indication of a suspect’s ethnicity. Evgeny Katz at Clarkson University, US, in collaboration with Jan Halámek, now at the State University of New York at Albany, analysed levels of two biomarkers – creatine kinase and lactate dehydrogenase – in the blood of people of Caucasian and African American ethnicity. They then developed a bioassay to amplify the differences in these levels. The test could successfully distinguish between ethnicities in real human blood samples, as well as samples a day old, as could well be the case at a crime scene.

To find out more, read the full article on Chemistry World.

Solid-state Forensic Finger sensor for integrated sampling and detection of gunshot residue and explosives: towards ‘Lab-on-a-finger’
Amay J. Bandodkar, Aoife M. O’Mahony, Julian Ramírez, Izabela A. Samek, Sean M. Anderson, Joshua R. Windmiller and Joseph Wang
Analyst, 2013,138, 5288-5295
DOI: 10.1039/C3AN01179H, Paper

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, 2013,138, 6251-6257
DOI: 10.1039/C3AN01062G, Communication

UK researchers have used vibrational spectroscopy to chemically image the cross section of a prostate to such an incredible level of detail that each of the 66 million pixels in the image represents a piece of tissue only 5.5 × 5.5µm.

Biopsies are regularly taken to diagnose cancer and provide a snapshot of the disease. Trained histopathologists examine the samples under powerful optical microscopes using several specialist stains to highlight particular characteristics of cells or tissues in a time-consuming process.

Peter Gardner of the University of Manchester and colleagues hope their technique, which uses Fourier transform infrared (FTIR) chemical imaging, will eventually be turned into an automated system that can grade and stage biopsy samples 24 hours a day by identifying certain chemical signatures.

To read the full article, please visit Chemistry World.

Whole organ cross-section chemical imaging using label-free mega-mosaic FTIR microscopy
Paul Bassan, Ashwin Sachdeva, Jonathan H. Shanks, Mick D. Brown, Noel W. Clarke and Peter Gardner
Analyst, 2013,138, 7066-7069
DOI: 10.1039/C3AN01674A, Communication

Scientists in Canada and the US hope a system they have developed for monitoring amyloid-β aggregation on a chip could be used to find new treatments for Alzheimer’s disease.

Alzheimer’s disease is a complex neurodegenerative condition and the most common cause of dementia. In the US, more than 5 million people are estimated to have the condition. There is currently no known cure. Research has uncovered that the self-aggregation of the amyloid-β (Aβ) peptide plays a vital role in the development of Alzheimer’s disease. Methods that study the interaction of Aβ with potential new drugs are therefore extremely important.

Now, Kagan Kerman at the University of Toronto at Scarborough, and colleagues, have created a sensing platform to aid the drug screening process. ‘We have successfully demonstrated a novel method for high throughput screening of small molecules modulating Aβ growth and it provides a promising platform to facilitate therapeutics discovery for Alzheimer’s disease,’ says Kerman.

To read the full article, please visit Chemistry World.

LED-based interferometric reflectance imaging sensor for the detection of amyloid-β aggregation
Xin R. Cheng, George G. Daaboul, M. Selim Ünlü and Kagan Kerman
Analyst, 2014, Advance Article
DOI: 10.1039/C3AN01307C, Paper