Jury :

• Sabine SZUNERITS, PREX, University of Lille (Supervisor)
• Vincent BOUCHIAT, Research Director, Institute Néel (Rapporteur)
• José Luis TOCA-HERRERA, Research Director, Institute of Biophysics (Rapporteur)
• Wolfgang KNOLL, Professor, Austrian Institute of Technology (supervisor)

Summary:

The choice between optical detection principles and electrical concepts for biomedical diagnostics has not yet been decided. Both approaches continue to offer solutions for rapid, multiplexed, simple and inexpensive detection of relevant biological molecules. However, if small analytes are to be detected and/or if the analyte binding density at the transducer surface is low, label-free optical detection is problematic. In this work, an innovative and versatile detection platform was developed, combining an electrical and optical readout device to compare signals during real-time biological recognition. It is based on coupling the reading of a graphene-based field effect transistor (gFET) with that of surface plasmon resonance (SPR). Various types of link, including biotin/neutravidin, PNA/DNA and ssRNA/ssDNA aptamer for protein detection, were studied and the results discussed.

Abstract:

The race in biomedical diagnostics between optical detection principles and electrical concepts is not decided yet. Both approaches continue to offer solutions for fast, multiplexed, simple and cheap detection of biological relevant molecules. However, if it comes to the detection of small analytes and/or if the achievable analyte binding density at the transducer surface is low, label-free optical detection schemes have a problem because the change in the optical interfacial architecture induced by the mere binding of the analyte may be simply too minute to be detected. In this work, an innovative and versatile sensing platform, combining an electrical and optical read-out device to compare the different signal behaviours during a biological binding event in real time was developed. It is based in coupling the read out of a graphene-based field-effect transistor (gFET) with that of surface plasmon resonance (SPR). Various binding events including biotin/neutravidin, PNA/DNA and ssRNA/ssDNA aptamers for protein detection were investigated and the results discussed.