Rachel Blakeburn – Chemical Communications Blog

Author Archive

Glucometers altered to detect HIV

19 Sep 2012

Glucometers used by diabetic patients can be altered to detect HIV-related DNA sequences, say scientists in China.

The commercially available personal glucometer has been the most successful point-of-care (POC) device up to date. But the glucometer only responds to glucose. Extending its use to monitoring different types of targets would potentially revolutionise POC technology.

The team used invertase, an enzyme that catalyses the hydrolysis of sucrose into glucose, to interpret DNA recognition events into readouts measurable by the glucometer.

They loaded nanoparticle amplification labels with invertase, which, through target/probe DNA hybridisations, catalysed the conversion of sucrose on the sensing surface to glucose. They could detect as low as 0.5pM of target DNA. While they demonstrate the method with HIV DNA, it could potentially used to detect different DNAs.

Link to journal article
Sensitive point-of-care monitoring of HIV related DNA sequences with a personal glucometer
J Xu et al
Chem. Commun., 2012, DOI: 10.1039/c2cc35941c

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Micromotors with built in compasses

12 Sep 2012

Iron containing microtubular engines can be magnetised and act as compass needles

A collaboration between scientists in Germany and Singapore has produced a micromotor that can be controlled by a magnetic field.

The motors are microtubes that contain a platinum catalyst and iron. The catalyst reacts with hydrogen peroxide to produce a jet of oxygen bubbles to drive the tube forward and the iron allows the tubes to react to a magnet. Gaining control of the direction in which the tubes travel is the challenge, and now scientists have found a way to manipulate the direction using magnets. This is a step towards a future in which they could be used inside the body, as engines in nanoscale systems or for environmental remediation.

Martin Pumera, who is based at Nanyang Technological University, Singapore, and his team, worked with researchers from the Leibniz Institute for Solid State and Materials Research Dresden, Germany, to make the micromotors. First they deposited thin layers of titanium, iron, chromium and platinum on a support. Once the support was removed, the layers rolled into a tube. Next, the microtubes were made into permanent magnets, using a neodymium magnet, and put into a hydrogen peroxide solution to test their reaction to external magnets.

Read the full article in Chemistry World

Link to journal article
Micromotors with built-in compasses
G Zhao et al
Chem. Commun., 2012, DOI: 10.1039/c2cc35671f

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Improved organocatalyst

12 Sep 2012

UK scientists have developed a scalable, resolution-free synthesis of a helical DMAP organocatalyst.

In 2011 Dave Carbery (University of Bath) and colleagues made a helicene catalyst that they say was the most active chiral DMAP-like nucleophilic catalyst (DMAP = 4-dimethylamino pyridine). It was an effective catalyst for the acylative kinetic resolution of chiral secondary alcohols. With it, the team achieved reactions on a gram scale using only 1mg of catalyst – a 0.05mol% loading. However, the catalyst needed HPLC resolution.

They are now able to make more than 1g of the helical DMAP without any resolution. They say that it is also possible to do late-stage functionalisation.

Link to journal article
Point-to-helical chirality transfer for a scalable and resolution-free synthesis of a helicenoidal DMAP organocatalyst
M R Crittall, N W G Fairhurst and D R Carbery
Chem. Commun., 2012, DOI: 10.1039/c2cc35583c

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Refinery test for mesostructured zeolite

12 Sep 2012

The Y zeolite is used as a catalyst for fluid catalytic cracking. It has a high surface area and large pores and is thermally and hydrothermally stable. But scientists are working on improving the catalyst for a better performance. One reason is that the 7.4Å micropores are limited in terms of size of hydrocarbon that they can take in. The process involves diffusion of large hydrocarbon molecules into the crystals and diffusion of the desired intermediate cracking products (diesel or light oil, gasoline and liquefied petroleum gases) out.

Introducing wider pores allows large hydrocarbon molecules to go through the process. Scientists from Spain had recently carried out a templating process (using a surfactant) to introduce highly controlled mesoporosity into zeolites. This led to improved catalytic selectivity, in which more gasoline, light oil and liquefied petroleum gas were obtained.

The team have now scaled up the catalyst and tested its hydrothermal stability and catalytic cracking performance in a refinery. The catalyst showed much better product selectivity compared to the current catalyst, says the team.

Link to journal article
A mesostructured Y zeolite as a superior FCC catalyst – from lab to refinery
J Garcia-Martinez, K Li and G Krishnaiah
Chem. Commun., 2012, DOI: 10.1039/c2cc35659g

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Yong-Qiang Tu joins the ChemComm Editorial Board

30 Jul 2012

On behalf of the ChemComm Editorial Board, I am delighted to welcome Professor Yong-Qiang Tu as the new ChemComm Associate Editor for organic chemistry.

Professor Tu is a council member of Chinese Chemistry Society and the president of Gansu Chemistry Society. His current research interests centre on tandem rearrangement reactions and their application to the total syntheses of bioactive alkaloids, synthetic studies of biologically active natural products, and the construction of C-C and C-N bonds via C-H functionalisations.

Professor Tu’s editorial office is now open for submissions, welcoming urgent communications highlighting the latest advances in organic chemistry.

Find out more about Professor Tu’s research by reading these exciting articles:

Total synthesis of (±)-maistemonine and (±)-stemonamide
Zhi-Hua Chen, Yong-Qiang Zhang, Zhi-Min Chen, Yong-Qiang Tu and Fu-Min Zhang
Chem. Commun., 2011,47, 1836-1838, DOI: 10.1039/C0CC02612C, Communication

Enantioselective bromination/semipinacol rearrangement for the synthesis of β-bromoketones containing an all-α-carbon quaternary center
Hui Li , Fu-Min Zhang , Yong-Qiang Tu , Qing-Wei Zhang , Zhi-Min Chen , Zhi-Hua Chen and Jian Li
Chem. Sci., 2011,2, 1839-1841, DOI: 10.1039/C1SC00295C

Are you an organic chemist based in North America? Submit your research to Michael Krische, ChemComm North American Associate Editor for organic chemistry.

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Quick and clean way to make intermediates for dyes and pharmaceuticals

30 Jul 2012

Scientists in China have developed a quick and clean way to reduce nitroarenes to aminoarenes, which are common intermediates for making dyestuffs, pharmaceuticals and agricultural chemicals.

Sodium borohydride and molecular hydrogen are commonly used for this reaction but their hydrogen elements cannot reduce nitroarenes under mild reaction conditions. Usually, expensive noble-metal catalysts are necessary to activate the hydrogen elements in the reductants.

Here, the researchers have used a vanadium-doped porous TiO₂ with highly active hydrogen, which can instantly (<10s) and selectively reduce nitroarenes to aminoarenes under ambient conditions without catalysts. After being consumed by nitroarenes, the active hydrogen species can be regenerated by irradiating the V-doped TiO₂ with UV light.

Link to journal article
Porous vanadium-doped titania with active hydrogen: a renewable reductant for chemoselective hydrogenation of nitroarenes at ambient condition
J Su et al
Chem. Commun., 2012, DOI: 10.1039/c2cc33969b

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Silica sheets to deliver DNA into cells for disease prevention and treatment

17 Jul 2012

Scientists in Japan have made a new DNA delivery substrate based on networks of bio-friendly upright silica sheets. The network of sheets forms a porous film on to which they can immobilise DNA, ready for delivery (transfection) into cells. The transfection efficiency of the silica film is approximately double that of solution-based transfection. Gene transfection is a potential method for preventing and treating diseases and analysing cell functions.

Link to journal article
Silica-based Gene Reverse Transfection: Upright Nanosheet Network for Promoted DNA Delivery to Cell
Q Ji et al
Chem. Commun., 2012, DOI: 10.1039/c2cc34289h

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Bendy non-volatile flash memory data storage device

11 Jul 2012

Scientists in Taiwan have made a flexible memory device, which they say could open up a new design approach for high performance flexible non-volatile resistive memory devices. Non-volatile devices are computer memory devices that can retain stored information even when not powered, for example read-only memory, flash memory, hard drives and floppy disks.

The team’s device consists of a single-layer donor-acceptor conjugated polymer fabricated on plastic polyethylene naphthalene. It displayed a low threshold voltage (±2V), low switching power (~100µW cm^-2), large on/off memory window (10⁴), good retention (>10⁴s) and excellent endurance against electrical and mechanical stimuli, they say.

Link to journal article
Poly(fluorene-thiophene) Donor Tethered Phenanthro[9,10-d]imidazole Acceptor for Flexible Nonvolatile Flash Resistive Memory Devices
H-C Wu et al
Chem. Commun., 2012, DOI: 10.1039/c2cc34257j

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Chemical Communications Blog

Author Archive

Glucometers altered to detect HIV

Micromotors with built in compasses

Improved organocatalyst

Refinery test for mesostructured zeolite

Yong-Qiang Tu joins the ChemComm Editorial Board

Quick and clean way to make intermediates for dyes and pharmaceuticals

Silica sheets to deliver DNA into cells for disease prevention and treatment

Bendy non-volatile flash memory data storage device

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