Ioulia Tzouvadaki

Label-free detection of prostate-cancer biomarkers

Ioulia Tzouvadaki
, PhD Student, EPFL-IC-LSI
Sandro Carrara, Lecturer and Senior Scientist, EPFL-IC-LSI


Theory and modelling:
Theoretical and computational investigation of the relationship between the voltage gap of the current/voltage characteristics appearing after the bio-functionalization and the presence of antigens on the surface and the biosensing. Study of the memristive behavior and its role for bio-detection purposes.

Equivalent circuit of a memristive-biosensor

Development of an equivalent circuit model that successfully emulates the behavior of the physical system. Through simulations and modeling, it is demonstrated that experimental results obtained by the electrical characterization of bare silicon nanowire devices present a current to voltage characteristic curve equivalent to that of a memristor device according to the theoretical aspect existing in literature. The voltage gap appearing at the current to voltage characteristics for nanowires with bio-modified surface can be also reproduced through computational study and can be modeled and simulated.

Fitting among current voltage characteristic of an equivalent circuit of a memristive-biosensor and measurements acquired during bio-sensing


Experimental part:

  • Nanowire arrays will be fabricated by using conventional lithographic techniques and/or multi-spacer patterning technique
  • Nanowire arrays will be functionalised with antibodies directly or through a self-assembled monolayer of ethylene glycol
  • Direct covalent attachment of the antibody to the surface involves silanisation of the wires -GPTS(3-glycidoxypropyltrimethoxysilane) followed by reaction of the amino group of the antibodies with the gycidoxy group of GPTS and alternative functionalisation methods will also be considered
  • Current/voltage characteristics will be acquired on the fabricated and functionalised nanowires in order to demonstrate their applicability to sense cancer markers