Aptamere und Geruchsstoffbindeproteine - innovative Rezeptoren für das elektronische Sensing von kleinen Molekülen
Lead partner:
Danube Private University
Scientific management:
Wolfgang Knoll
Additional participating institutions:
Universität Ulm
Field(s) of action:
Environment, climate and ressources
Scientific discipline(s):
1040 - Chemie (70 %)
1030 - Physik, Astronomie (10 %)
1060 - Biologie (20 %)
Funding tool: Basic research projects
Project-ID: FTI22-G-012
Project start: 01. Juli 2023
Project end: 30. Juni 2027
Runtime: 48 months / ongoing
Funding amount: € 300.000,00
Brief summary:
Quantitative monitoring of small analytes in clinically relevant fluids or in air remains a challenge both from a fundamental point of view as well as for practical applications. In all cases, one is facing three major problems: (i) the sensitivity of the transducer; (ii) the selectivity needed to differentiate between competing analytes; and (iii) the suppression of non-specific binding events.
When dealing with electronic sensing concepts, Graphene-based Field-Effect Transistors (gFETs) stand out for their small size, excellent electrical characteristic, and high sensitivity to near surface charges and electrical fields. Specificity to the target analyte can be integrated into gFETs via surface attachment of target-specific receptors; yet the very small Debye length in (physiological) buffer solutions limits the signal strength considerably.
A first focus of the proposed research is the impact of the applied surface chemistry used for the immobilization of these receptor on the transducer surface and how this coupling affects the final sensing signals. A second effort addresses options for manipulating the Debye limitations by the co-assembly of polymer brushes on the sensor surface.
For the extension of these studies to monitoring THC directly in air, we propose to mimic the natural mucosa by an ultrathin (a few 10 nm in thickness) hydrogel coating on top of the transistor that protects the sensitive bioorganic components against air by keeping them in a fully hydrated state, without preventing the VOCs getting access to the receptors on the sensor surface by diffusing through the hydrogel layer.
The members of the DPU team are highly complementary in their expertise to tackle these complex and multidisciplinary challenge: they have been working for many years on OBPs for smell sensing, on the use of aptamers for medical biosensing, and has experts in surface immobilization of receptors and electronic sensing.
Keywords:
Sensorik, (Atem)gas Analytik, RGO-Feldeffekttransistor, Rezeptorsystems
Results
Peer-reviewed publication
We report on the synthesis of “clickable” graphene nanoribbons (GNRs) and their application as a versatile interface for electrochemical biosensors. GNRs are successfully deposited on gold-coated working electrodes and serve as a platform for the covalent anchoring of a bioreceptor (i.e., a DNA aptamer), enabling selective and sensitive detection of Interleukin 6 (IL6). Moreover, when applied as the intermediate linker on reduced graphene oxide (rGO)-based field-effect transistors (FETs), the GNRs provide improved robustness compared to conventional aromatic bi-functional linker molecules. GNRs enable an orthogonal and covalent attachment of a recognition unit with a considerably higher probe density than previously established methods. Interestingly, we demonstrate that GNRs introduce photoluminescence (PL) when applied to rGO-based FETs, paving the way toward the simultaneous optical and electronic probing of the attached biointerface.
https://doi.org/doi.org/10.1039/D3NH00590A
https://pubs.rsc.org/en/content/articlelanding/2024/nh/d3nh00590a
Affinity-based biosensors employing surface-bound biomolecules for analyte detection are important tools in clinical diagnostics and drug development. In this context, electrolyte-gated organic transistors (EGOTs) are emerging as ultrasensitive label-free biosensors. In this study, we present an EGOT sensor integrated within a microfluidic system. The sensor utilizes the cytomegalovirus (CMV) phosphoprotein 65 as a biorecognition element to detect the pathological biomarker human anti-cytomegalovirus antibody in solution. The biorecognition element is grafted onto the gate electrode by exploiting the polyhistidine-tag technology. Real-time monitoring of the EGOT response, coupled with a two-compartment kinetic model analysis, enables the determination of analyte concentration, binding kinetics, and thermodynamics of the interaction. The analysis of the relevant kinetic parameters of the binding process yields a reliable value for the thermodynamic equilibrium constant and suggests that the measured deviations from the Langmuir binding model arise from the co-existence of binding sites with different affinities toward the antibodies.
https://doi.org/10.1016/j.xcrp.2024.101919
https://www.sciencedirect.com/science/article/pii/S2666386424001668
- H. Xing, Y. Zhang, R. Li, H.-M. Ruzicka, C. Hain, J. Andersson, A. Bozdogan, M. Henkel, U. Knippschild, R. Hasler, C. Kleber, W. Knoll, A.-K. Kissmann, F. Rosenau Nanoscale Horiz., 2025, 10, 124-134.
https://doi.org/10.1039/D4NH00281D
- R. Hasler, P. A. Livio, A. Bozdogan, S. Fossati, S. Hageneder, V. Montes-García, J. Movilli, T. Moazzenzade, L. Loohuis, C. Reiner-Rozman, A. Tamayo, C. Fiedler, M. Ibáñez, C. Kleber, J. Huskens, J. Dostalek, P. Samorì, W. Knoll IEEE Sens. J, 2025, 25, 7, 10521-10529. DOI 10.1109/JSEN.2025.3533113
https://doi.org/10.1109/JSEN.2025.3533113
- Y. Zhang, H. Xing, R. Li, J. Andersson, A. Bozdogan, R. Strassl, B. Draphoen, M. Lindén, M. Henkel, U. Knippschild, R. Hasler, C. Kleber, W. Knoll, A.-K. Kissmann, F. Rosenau Adv. Healthc. Mater, 2025, 14, 2403827.
https://doi.org/10.1002/adhm.202403827
- J.-C. Walter, A.-K. Kissmann, D. Gruber, D. Alpízar-Pedraza, E. M. Martell-Huguet, N. Preising, A. Rodriguez-Alfonso, L. Ständker, C. Kleber, W. Knoll, S. Stenger, C. Firacative, F. Rosenau Biomolecules, 2025, 15, 322.
https://doi.org/10.3390/biom15030322
- G. Bolotnikov, A.-K. Kissmann, D. Gruber, A. Bellmann, R. Hasler, C. Kleber, W. Knoll, F. Rosenau Biosensors, 2025, 15, 7, 448.
https://doi.org/10.3390/bios15070448