Aptamers and Odorant Binding Proteins – Innovative Receptors for Electronic Small Ligand Sensing

Programme

FTI-Strategie Lower Austria 2012-2027

Project coordination

Danube Private University, Univ.-Prof. Dr. Christoph Kleber

Project partners

University Ulm

Researchers involved at DPU 

• Hon.-Prof. Prof. Dr. Wolfgang Knoll
• Dipl.-Ing. Dr. Roger Hasler
• Wiktor Luczak, MSc

Abstract

The quantitative detection of small analytes in clinically relevant fluids or in air currently represents a significant challenge, both from a scientific perspective and for practical applications. The key factors involved are (i) the sensitivity of the transducer, (ii) the selectivity required to distinguish between competing analytes, and (iii) the suppression of non-specific binding events. Among electronic sensing concepts, graphene-based field-effect transistors (gFETs) stand out due to their small size, excellent electrical properties, and high sensitivity to surface-near charges and electric fields. Specificity for a given target analyte can be introduced in gFETs by functionalizing the surface with target-specific receptors. However, the very short Debye length in (physiological) buffer solutions significantly limits the signal strength.

A central focus of the proposed work is to investigate the influence of the surface chemistry used to immobilize these receptors on the transducer surface, and how this coupling affects the resulting measurement signals. Another approach addresses strategies to overcome Debye screening limitations, for example through the use of polymer brushes or hydrogels on the sensor surface.

To extend these studies toward the detection of THC directly in air, we propose to mimic the natural mucosal environment by applying an ultrathin hydrogel layer onto the transistor. This layer protects the sensitive bio-organic components from air exposure by maintaining them in a fully hydrated state, while still allowing volatile organic compounds to reach the surface receptors through diffusion across the hydrogel layer.

Read more about the project