Nanoscale bioelectrical characterization

Gabriel Gomila | Group Leader
Lázaro René Izquierdo | Postdoctoral Researcher
Maria Chiara Biagi | PhD Student
Marc Van der Hofstadt | PhD Student

Former Members
Dr. Laura Fumagalli | Senior Researcher
Dr. Annalisa Calò | Postdoc
Now: Postdoc at the Institut Catala de Nanociencia i Nanotecnologia (ICN2)
Dr. Aurora Dols-Pérez | Postdoc
Now: Postdoc at the Institut de Quimica Avançada de Catalunya (CSIC)
Dr. Martin Edwards | Postdoc
Now: Postdoc, University of North Carolina at Chapel Hill
Daniel Esteban Ferrer | PhD Student
Georg Gramse | PhD Student
Now: Marie Curie postdoc, Johannes Kepler University, Linz, Austria
Dr. Jordi Otero | Postdoc


The main goal of our research group is to develop new experimental setups based on atomic force microscopy and theoretical frameworks enabling the measurement of the electrical properties of biological samples at the nanoscale (for example, biomembranes, single viruses or single bacteria). Our main objective is to contribute to develop new label-free biological characterization methods and new electronic biosensors.

During 2014 we have quantified for the first time the dielectric properties of the most important biomolecule of life, DNA. The value obtained is four times larger than previously assumed values. This result will have important implications in the evaluation of DNA electrostatic interactions with proteins and drugs. We have also been able to determine the electric polarization response of single bacteria cells for the first time. Important differences between gram types have been found, which we could associate to the different structure and hydrophilic character of the cell wall. Finally, we have expanded our electrical measuring capabilities to the high frequency range (> GHz) with the use of the Scanning Microwave Microscope. We contributed to develop a novel calibration method, not requiring a calibration sample and, hence, of simple implementation. Application to test systems and bacteria samples have been undertaken.

Electrical potential distribution corresponding to the electric interaction between a voltage biased nanometric sharp conducting tip of radius 5 nm and a single virus particle. The virus is represented as core-shell structure with a protein shell 2.5 nm thick and a DNA core 32 nm high and 55 nm wide. From the calculated electric potential distribution the polarization force acting on the sharp tip can be calculated and compared to experimental measurements. With this procedure we determined the dielectric polarization response of DNA giving a relative dielectric constant of εr ~8, four times higher than conventionally assumed


Topographic (left) and dielectric (right) images of a Salmonella Thymuirium bacterium measured with an electrostatic force microscope. Quantification of the dielectric image gives a bacterium relative dielectric constant of εr= 7 when measured in ambient conditions. This value is higher than the one obtained in dry air conditions (εr= 5) and reveals information on the hydration properties of the cell wall and of its hydrophilic or hydrophobic character


IBEC internal collaboration succeeds in measuring bacterial cell response to electrical fields

Two groups working together at IBEC demonstrate the potential of electrical studies of single bacterial cells in a paper published in ACS Nano. Gabriel Gomila’s Nanoscale Bioelectrical Characterization group and that of Antonio Juárez, Microbial Biotechnology and Host-pathogen Interaction, combined their expertise on microscopic electrical measurements and bacteria respectively to come up with a way to study the response to external electrical fields of just a single bacterial cell.

Researchers measure a property of DNA for the first time

The electric polarizability of DNA is a fundamental property that directly influences its biological functions. Despite the importance of this property, however, its measurement has remained elusive so far. In a study published in PNAS today, researchers at Barcelona’s Institute for Bioengineering of Catalonia (IBEC) led by Laura Fumagalli, senior researcher at IBEC and lecturer at the University of Barcelona, and their collaborators at the Institute for Research in Biomedicine (IRB) and at Barcelona Supercomputing Center (BSC), and at Centro Nacional de Biotecnologia (CNB-CSIC) and IMDEA Nanociencia in Madrid, describe how they have found a way to directly measure DNA electric polarizability – represented by its dielectric constant, which indicates how a material reacts to an applied electric field – for the first time ever.

IBEC research on the cover of Nanotechnology

The latest article published by IBEC’s Nanoscale bioelectrical characterization group has made the cover of the journal Nanotechnology.

“Nanomicrowave” cooking up something new

A new European Marie Curie Initial Training Network involving IBEC’s Nanoscale Bioelectrical Characterization group will attempt to bring research into microwaves – which are extensively used in a host of applications such as telecommunications, microwave ovens and radar – to a whole new level.

‘Fingerprinting’ nanoscale objects and viruses

Scientists at IBEC in Barcelona have found a way of effectively identifying nanoscale objects and viruses that could offer a breakthrough for biomedical diagnostics, environmental protection and nano-electronics.

Microscope development project for sub-surface imaging at the nanoscale

IBEC’s Nanoscale Bioelectrical Characterization group, headed by Gabriel Gomila, is a partner in a new EU-funded collaborative project set to develop a new tool for non-destructive 3D nanoscale structural characterization, the Volumetric Scanning Microwave Microscope (VSMM).

New technique to study the electrical activity of the cellular membrane

Gabriel Gomila and Laura Fumagalli, from the Nanoscale bioelectrical characterization line at IBEC, are two of the authors of the study.


EU-funded projects
NANOMICROWAVE Microwave Nanotechnology for Semiconductor and Life Sciences MARIE CURIE – ITN Gabriel Gomila
V-SMMART Nano Volumetric Scanning Microwave Microscopy Analytical and Research Tool for Nanotechnology NMP – SME Gabriel Gomila
AFM4NanoMed&Bio European network on applications of Atomic Force Microscopy to Nanomedicine and Life Sciences EU COST Action TD1002 Gabriel Gomila (Management Committee Substitute Member)
National projects
NANOELECTOMOGRAPHY Electrical nanotomography based on scanning probe microscopy for nanomaterials and biological samples MICINN (TEC2013-48344-C2-1-P) Gabriel Gomila


Birhane, Y., Otero, J., Pérez-Murano, F., Fumagalli, L., Gomila, G., Bausells, J., (2014). Batch fabrication of insulated conductive scanning probe microscopy probes with reduced capacitive coupling Microelectronic Engineering 119, 44-47

Gramse, G., Kasper, M., Fumagalli, L., Gomila, G., Hinterdorfer, P., Kienberger, F., (2014). Calibrated complex impedance and permittivity measurements with scanning microwave microscopy Nanotechnology 2514, 145703 (8)

Cuervo, A., Dans, P. D., Carrascosa, J. L., Orozco, M., Gomila, G., Fumagalli, L., (2014). Direct measurement of the dielectric polarization properties of DNA Proceedings of the National Academy of Sciences of the United States of America 11135, E3624-E3630

Esteban-Ferrer, Daniel, Edwards, Martin Andrew, Fumagalli, Laura, Juarez, Antonio, Gomila, Gabriel, (2014). Electric polarization properties of single bacteria measured with electrostatic force microscopy ACS Nano American Chemical Society 810, 9843–9849

Gomila, G., Gramse, G., Fumagalli, L., (2014). Finite-size effects and analytical modeling of electrostatic force microscopy applied to dielectric films Nanotechnology 2525, 255702 (11)

Caló, A., Reguera, D., Oncins, G., Persuy, M. A., Sanz, G., Lobasso, S., Corcelli, A., Pajot-Augy, E., Gomila, G., (2014). Force measurements on natural membrane nanovesicles reveal a composition-independent, high Young's modulus Nanoscale 64, 2275-2285

Fumagalli, L., Edwards, Martin Andrew, Gomila, G., (2014). Quantitative electrostatic force microscopy with sharp silicon tips Nanotechnology 2549, 495701 (9)

Dols-Perez, A., Fumagalli, L., Gomila, G., (2014). Structural and nanomechanical effects of cholesterol in binary and ternary spin-coated single lipid bilayers in dry conditions Colloids and Surfaces B: Biointerfaces 116, 295-302

Gramse, G., Dols-Perez, A., Edwards, M. A., Fumagalli, L., Gomila, G., (2013). Nanoscale measurement of the dielectric constant of supported lipid bilayers in aqueous solutions with electrostatic force microscopy Biophysical Journal 1046, 1257-1262

Dols-Perez, A., Sisquella, X., Fumagalli, L., Gomila, G., (2013). Optical visualization of ultrathin mica flakes on semitransparent gold substrates Nanoscale Research Letters 81, 1-5

Gomila, G., Esteban-Ferrer, D., Fumagalli, L., (2013). Quantification of the dielectric constant of single non-spherical nanoparticles from polarization forces: Eccentricity effects Nanotechnology 2450, 505713

Gramse, G., Edwards, M.A., Fumagalli, L., Gomila, G., (2013). Theory of amplitude modulated electrostatic force microscopy for dielectric measurements in liquids at MHz frequencies Nanotechnology 2441, 415709

Gramse, G., Edwards, M. A., Fumagalli, L., Gomila, G., (2012). Dynamic electrostatic force microscopy in liquid media Applied Physics Letters 10121, 213108

Fumagalli, Laura, Esteban-Ferrer, Daniel, Cuervo, Ana, Carrascosa, Jose L., Gomila, Gabriel, (2012). Label-free identification of single dielectric nanoparticles and viruses with ultraweak polarization forces Nature Materials Nature Publishing Group 119, 743-826

Gramse, G., Gomila, G., Fumagalli, L., (2012). Quantifying the dielectric constant of thick insulators by electrostatic force microscopy: effects of the microscopic parts of the probe Nanotechnology 2320, 205703

Dols-Perez, Aurora, Fumagalli, Laura, Cohen Simonsen, Adam, Gomila, Gabriel, (2011). Ultrathin spin-coated dioleoylphosphatidylcholine lipid layers in dry conditions: A combined atomic force microscopy and nanomechanical study Langmuir 2721, 13165-13172


  • Cypher Atomic Force Microscope (Asylum Research)
  • 2 Cervantes Atomic Force Microscopes (Nanotec Electronica)
  • Easy Scan 2 Atomic Force Microscope (Nanosurf)
  • AxioImager A1m Reflection Optical Microscope (Zeiss) equipped with a AxioCam ERc5s (Zeiss)
  • HF2LI digital lock-in amplifier (Zurich Instruments)
  • CompactStat portable electrochemical interface and impedance analyzer (Ivium Technologies)
  • 2 eLockIn204 4-phase Lock-In amplifiers (Anfatec)
  • Keithley 6430 sub-femtoAmp remote sourcemeter (Keithley)


  • Prof. Jose L. Carrascosa
    Department of Structure of Macromolecules, Centro Nacional de Biotecnología, Spain
  • Dr. Manel Puig
    Departament d’Electrònica, University of Barcelona, Spain
  • Dr. Ferry Kienberger
    Agilent Technologies Austria, Linz, Austria
  • Dr. Adriana Gil
    Nanotec Electronica S.L., Madrid, Spain
  • Prof. Modesto Orozco
    Institut de Recerca Biomèdica, Barcelona, Spain
  • Prof. Marco Sampietro
    Laboratorio di Strumentazione Analogica e Materiali Polimerici, Politecnico di Milano, Italy
  • Prof. Joan Bausells
    Centro Nacional de Microelectrónica de Barcelona-CSIC, Spain

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