Nanoprobes and nanoswitches
Prof. Dr.
Gorostiza, Pau
(ICREA Research Professor)
Group Leader
Edifici Hèlix | Baldiri Reixac 15-21 | 08028 | Barcelona
Email : pgorostiza
ibecbarcelona.eu
Research Topics
Mechanics and nanostructure of biomembranes / Molecular self-assembling / Electrochemical STM-STS / Nanoelectrochemistry / Optical switches and protein nanoengineering
The group’s research focuses on developing nanoscale tools to study biological systems. These tools include instrumentation based on proximity probes, such as electrochemical tunnelling microscopy and spectroscopy, that we apply to investigate electron transfer in metal oxides and individual redox proteins. These studies are relevant to the development of biosensors and molecular electronics devices.
Prof. Dr. Sanz, Fausto
Group Leader
Dept. Química Física | Universitat de Barcelona | Martí i Franquès 1 | 08028 | Barcelona
Email: fsanz @ ibecbarcelona.eu
Crystal structure of redox protein azurin (Protein Data Bank entry: 1AZU) displaying its solvent accessible surface (gold) superimposed on the tertiary structure (rainbow) and a red sphere indicating the copper ion. When an atomically flat gold electrode is coated with azurin, the protein can be imaged under potentiostatic control by electrochemical tunneling microscopy (3D rendering of a 100x100nm2 area shown in blue), and its electron transfer properties can be investigated by current-distance spectroscopy (Juan Manuel Artés et al., ACS Nano 2011).
In particular, we have recently published a method to measure directly the distance decay constant that characterizes the rate of electron transfer (ET) in redox proteins, and we have reported single protein junctions consisting of azurin bridged between a gold substrate and the probe of an electrochemical tunneling microscope, which constitute a proof-of-principle of a single redox protein field-effect transistor. Another set of nanotools that we are developing is based on molecular actuators that can be switched with light, such as azobenzene, which can be chemically attached to biomolecules in order to optically control their activity.
Representation of the invasive manipulation of neuronal activity by means of a conventional glass electrode in contact with the neuron on the left, and noninvasively by means of a focalized light beam over the green neuron on the right (Photomontage: Mercè Izquierdo).
We are specifically interested in the processes of neurotransmitter secretion by exocytosis and membrane recycling by endocytosis, which are the fundamental phenomena that occur at the synaptic terminal and that participate in the communication between neurons. We have recently set up a method to control neurotransmitter exocytosis with light at the presynaptic compartment by activating a calcium-permeable, light-gated glutamate receptor (LiGluR) in cultured cells. Presynaptic expression of LiGluR in hippocampal neurons enables direct and reversible control of neurotransmission with light, and has allowed for the first time to modulate the firing rate of the postsynaptic neuron with the wavelength of illumination.
