Aug 14, 2013
Sticky electrodes capture environmental nanoparticles
Methods for the detection of nanoparticles in the environment are urgently needed to help monitor the impact of these materials on biological systems. Both the small size and the dilute concentrations of nanoparticles encountered pose severe challenges to the analytical chemist using established techniques. Now, recent work at Oxford University has shown that an electroanalytical method may provide a simple, cheap and sensitive solution to the problem.
The idea is to chemically modify the surface of disposable electrodes so that nanoparticles impacting on them are immobilised. In this way electrodes can be distributed across environmental aquatic systems, left for a period of time during which their surfaces accumulate nanoparticles, recovered and then analysed either in the field or back in the lab.
The final analysis often simply involves the electrochemical oxidation of the accumulated material. Here, the potential required indicates the nature of the nanoparticle whilst the electrical charge required indicates the amount.
Experiments with silver nanoparticles show most encouraging results, even under challenging conditions such as the complex matrix of oceanografic water samples. A patent application has been filed recently and the inventors are presently seeking to commercialise the work.
The researchers presented their work in the journal Nanotechnology 24 295502
About the author
Richard G Compton is a Professor of Chemistry and Aldrichian Praelector at Oxford University (UK) and CAS Visiting Professor at the Institute of Physical Sciences, Hefei (PR China). He has published in excess of 1000 papers, numerous patents and 6 books including the graduate text 'Understanding Voltammetry' (Imperial College Press). In addition to sensing nanoparticles, IP from the group has realised the world’s first calibration-free pH meter (Senova) which won the best new product award at Pittcon 2013, sensors for measuring the heat of products contining chilli extracts (BioX, Singapore) and instrumentation for electrochemical AFM (Asylum). Dr Kristina Tschulik joined Professor Compton's group as a post-doctoral researcher in November 2012, mostly focussing on nanoelectrochemistry and analytical chemistry. She performed her doctoral studies at the IFW Dresden (Germany) in the field of magneto-electrochemistry, namely structured electrodeposition in gradient magnetic fields and received her doctoral degree from the Dresden University of Technology in April 2012. K.T. holds a "Diplom" (German equivalent to a Master's degree) in Chemistry and was granted a prestigious Marie Curie IEF Fellowship in June 2013 to continue her collaboration with the Oxford Group. Dr Robert G. Palgrave is a Lecturer in Chemistry at University College London. He specialises in X-ray photoelectron spectroscopy, thin film materials, solid state synthesis, photocatalysis and functional energy materials. Dr Christopher Batchelor-McAuley has to date published over 45 international peer-reviewed articles and is a co-author of the textbook 'Understanding Voltammetry: Problems and Solutions". He studied for his D.Phil under the guidance of Prof. R.G. Compton and upon completion (April 2012) he was award an EPSRC doctoral prize for the quality of his work (top 10-15%). CBM has continued as a post-doc within the Compton group where he is investigating the altered electrochemistry of nanoparticles and the mechanism of electron-transfer at the nanoscale.