Single-molecule large-area transistor sensors

Single-molecule Large-area trasistor sensors

The development of technologies capable of tracking a biomarker to concentrations at the physical limit is of paramount importance in early diagnostics of progressive diseases. Bioelectronic large-area transistors have been proved to be extremely powerful devices to achieve label-free and single-molecule detection of clinically relevant biomarkers.  The “Single molecule sensing group” exploits the know-how in materials science, condensed matter physics, process design and development, biosensor manufacturing, molecular interaction dynamics and the available facilities for micro- and nano-technologies.

In the framework of a long-standing collaboration with the Departments of Physics, Chemistry and Farmacy at the University of Bari, IFN “Single Molecule sensing group” research activity is focused on the development and fabrication of immuno-biosensors based on large-area electrolyte-gated field-effect transistors capable of selective and reliable detection of tumor markers, immunoglobulins, DNA, m-RNA, C-reactive protein with a sensitivity down to the single molecule. It is foreseen that the research activity may have a strong impact on key application fields such as point-of-care testing.


Fabrication of electrolyte gated transistors for single molecule biosensors:

  • Substrate: flexible (kapton, PEN), or rigid (silicon wafer, glass)
  • Interdigitated source and drain gold electrode: UV-Litho- & E-Beam Lithography fingers
  • Sensing gate: flexible or rigid substrate, bio-modified with ̴ 1012 bioreceptor/cm2


Multiscale analysis approach for intermolecular dynamics:

All layer biosensor components are investigated via molecular scale techniques:

  • AFM, Kelvin probe force microscopy to image with nanometric resolution the surface potential simultaneously with the morphology and the local forces.
  • FTIR spectroscopy (ATR, PM-IRRAS), micro-Raman imaging provide information about the moieties and the chemical environment involved in the receptor/biomarker binding process.



  • Clean Room fully equipped for micro- and nano-fabrication of devices (e-beam evaporator, soft reactive ion etching chamber, spin coater, mask aligner, rapid thermal annealer, surface profilometer, micro-wedge bonder, plasma-enhanced chemical vapor deposition chamber, wet chemical stations, device manipulation, cleaving and mounting stages.
  • Surface characterization labs: FE-SEM (Zeiss Sigma), EDS/EDX microanalysis (Oxford Instruments), electron beam litography (Raith), atomic force microscope (NT-MDT), Kelvin probe force microscopy, quantitative nanomechanical measurements in hybrid mode atomic force microscopy, TERS, FT-IR, ATR, PM-IRRAS (Nicolet-Thermo)




People involved:

Cinzia Di Franco

Gaetano Scamarcio

Riccardo Funari


Research units: