IBEC researchers have found a way to measure the rate of electron transfer (ET) – an important process which is essential in many chemical and biological processes such as cellular respiration and photosynthesis – at the single-molecule level.
In a study published in ACS Nano recently, members of IBEC’s Nanoprobes and Nanoswitches group describe how they used an electrochemical tunneling microscope to measure the ‘distance decay constant’ that characterises the rate of ET in redox proteins (proteins in which ET occurs). Analysis of decay constant measurements reveals differences between the reduced and oxidized states of a protein, that may be relevant to the control of ET rates in enzymes and biological electron transport chains.
“The study of ET is critical for the understanding how enzymes work, and is also needed to be able to move forward with technological applications in biosensing and molecular electronics,” explains Pau Gorostiza, group leader of IBEC’s Nanoprobes and Nanoswitches group alongside Fausto Sanz. “Methods to measure ET at the single-molecule level will help us resolve temporal variations in enzyme activity that can be correlated with conformational changes to allow the ultimate miniaturization of nanodevices.”
Pau and graduate student Juan Manuel Artés, first author of the study, have also recently participated in a project led by Concepció Rovira and Jaume Veciana at the Institute for Materials Science of Barcelona (ICMAB-CSIC). They’ve characterized a robust molecular switch in solution that operates at very low voltages, can be ‘patterned’ by electrical input and has exceptionally high long-term stability, reversibility and reproducibility. “This switch is a very promising platform for use in memory devices,” says Pau. “For example, on a CD coated with this molecule, bits can be ‘written’ electrochemically (by application of low voltages with a wire near the surface in certain conditions) and ‘read’ optically (measuring the absorbance or fluorescence) or magnetically.” Their results were published in Nature Chemistry yesterday.