Additive manufacturing of a multiplexed impedimetric biosensing system: laser-boosted nanolithography for targeted bacteria detection

• Applicant: Privatdozent Dr. Michael Hirtz
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering ; Biomedical Systems Technology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544666650

The proposed project aims to design and investigate a multiplexed (bio)sensing platform based on additively manufactured carbonaceous nanostructures on elastic biopolymer functional substrates and selectively tailored with phospholipid membranes. The nanostructures will be assembled by laser-induced graphitisation and scanning probe lithography. Phospholipids have shown higher mobility on graphene compared to other commonly used substrates such as silica, making this an attractive route for non-covalent immobilisation of various functional groups and recognition elements on graphene for biosensing applications. The proposed approach allows rapid and simultaneous fabrication of a variety of different carbon nanostructures on small areas, which can be directly functionalised with tailor-made phospholipid membranes and specific receptors, paving the way for inexpensive and readily available biosensors. The project goes beyond the current state of the art in several areas.The additive nanomanufacturing (ANM) process will be developed to induce one-step graphitisation and to modify natural materials lacking intrinsic aromatic structures, such as cellulose. By selective tuning of process parameters and substrate pretreatment, complex 3D mesostructures with tunable pore diameters, surface functional groups and good wettability will be formed, which are crucial for enhancing (bio)sensor capabilities by increasing the electrochemical surface area. The freedom of multielectrode arrays (MEA) design and fabrication enables a multiplex recognition of biomolecular interactions upon their surface functionalisation with different recognition elements - either directly or on lipid layers depending on type - for specific pathogen markers. Pathogenic E. coli strains will be selected as a proof-of-concept analyte for the studies. The multiplexed approach will allow a more thorough detection and enable distinction of the target to other strains with overlapping markers by fingerprinting the signal for all target markers instead of relying on only one. The mechanism of chemical-to-electrical signal processing within customisable receptor layers will be investigated and elucidated through experiment, simulation, and multivariate data analysis, where the multiplexed geometry will allow a deeper understanding of the substrate/lipid interface and push towards rapid screening and optimisation of substrate nanoarchitecture from the chemical to the morphological scale. Finally, multiparametric impedance discriminant analysis is applied to the second generation of optimised multiplexed MEA sensors for simultaneous multi-analyte diagnostics. The novelty starts with the coupling of MEA to the lipid layer a sa versatile tool for subsequent functionalisation, and culminates in the application of the multisine impedance tool, whichallows on-line in-situ monitoring and analysis of non-stationary chemical/physical binding processes at the analyte/lipid interfaces.

• DFG Programme: Research Grants
• International Connection: Poland
• Cooperation Partner: Professor Jacek Ryl