Chemical Communications Blog

A highly sensitive and regenerative electrochemical immunosenor has been created by scientists in China, by combining a 3D tetrahedra-structured probe (TSP) and a DNA-bridged antibody immobilisation technique.

Immunological TSP sensor

Chunhai Fan and colleagues from the Shanghai Institute of Applied Physics collaborated with scientists from the Nanjing University of Science and Technology. Together the team alleviated common problems associated with electrochemical biosensors, such as poor reproducibility and orientation of surface confined molecules, by using the TSP. Next, the team assembled the TSP onto the gold surface with high reproducibility, resulting in controlled spacing and orientation of the DNA probes. Antibodies were then reversibly anchored to the nanostructured surface via a DNA bridge, producing the immunological (iTSP) platform.

Fan believes that the iTSP platform will be a promising tool for various immunological assays, as well as DNA-programmed protein microarrays for future proteomic studies, and here’s a summary of the reasons why:-

1. This paper shows a simple one-step process to create the iTSP, which leads to a stable and reproducible surface for the anchoring of antibodies.
2. Conjugated antibodies are separated from the surface by a relatively thick iTSP layer, preventing possible surface-induced effects.
3. The protein resistant ability of iTSP is crucial for the proper orientation of the antibody conjugates and minimizes nonspecific adsorption that is often found in immunosensors.
4. The hollow structure of the tetrahedra makes it possible for redox molecules to easily penetrate the thick layer, supporting sensitive electrochemical detection.
5. The iTSP platform supports regeneration of the surface by using mismatched complementary DNA, which forms the basis of reusable immunosensors.

Fancy reading more? Then download the ChemComm communication, which will be free to access until the 24^th June 2011.

Fluorous tagging of DABCO through halogen bonding makes recyclable catalyst for well known organic reaction

Julien Legros and colleagues from the University of Paris-Sud, applied the fluorous tagging technique (often used in organometallic catalysis) to an organocatalyst, where the fluorous tags were ‘grafted’ in a supramolecular fashion through the halogen bond. The resulting catalyst is readily accessible and can be recovered using a simple precipitation and filtration method, allowing recyclability up to five times.

Fancy finding out more? Then download the ChemComm communication, which will be free to access until the 10^th June 2011.

An efficient iron oxide catalysed cross-coupling reaction between organometallic species and cyclic ethers, via activation of C(sp³)-H, has been developed by scientists in India. This is the first example of iron oxide mediated direct C-C bond formation without expensive or toxic ligands.

Metal catalysed cross-coupling reactions for C-C bond formation via C-H activation is a hot topic in catalysis research at the moment. Many reactions via the activation of C(sp²)-H have been reported, but examples via C(sp³)-H activation remain much more elusive. 

Iron oxide mediated C-C bond formation

Ram Vishwakarma and colleagues at the Indian Institute of Integrative Medicine have cleverly devised a cross-coupling reaction that does exactly that. They found that reacting alkyl- and aryl-magnesium halides with tetrahydrofuran (and other cyclic ethers) via activation of the C(sp3)-H results in C-C bond formation. The method is inexpensive (thanks to the cheap iron catalyst) and no toxic ligands are used.

I’m sure you’ll agree, this is an interesting addition to a hot research area and leaves me wondering about the impact this will have in research laboratories across the globe.

Fancy knowing more about the reaction conditions and substrates used in this reaction? Then download the ChemComm communication, which will be free to access until the 10th June 2011.

You may also be interested to know that Chemical Society Reviews recently published a themed issue on “C-H functionalisation in organic synthesis” guest edited by Huw M. L. Davies, Justin Du Bois and Jin-Quan Yu.

Chinese scientists have confirmed that Naringenin inhibits transforming growth factor-β (TGF-β) signaling in living cells.

Naringenin is a natural predominant flavanone with many pharmacology activities

TGF-β signalling plays a crucial role in a wide variety of biological processes, such as cell growth, differentiation, apoptosis, and embryonic development. Xiaohong Fang and colleagues from the Chinese Academy of Sciences, in Beijing, and co-workers from nearby Peking University, believe that developing TGF-β signalling inhibitors will help create new therapeutic reagents and anticancer drugs of the future. Here, Fang and his team have shown that Naringenin, a natural flavonone, inhibits this important signalling receptor, evidence supported by single-molecule fluorescence microscopy and single molecule force spectroscopy techniques. Fancy reading about the techniques used, or finding out more on the inhibition mechanism? Then download the ChemComm communication, which is free to access until the 3rd June 2011!