Periodic Reporting for period 1 - FLUFET (FLow detection of virUses by graphene Field Effect Transistor microarrays)
Reporting period: 2024-03-01 to 2025-02-28
The COVID-19 pandemic exposed critical weaknesses in the global response to emerging viral threats, particularly in the speed and accessibility of diagnostic testing. Traditional diagnostic tools, while accurate in centralized labs, suffer from long turnaround times, reliance on skilled personnel, and limited suitability for decentralized or resource-limited settings.
The FLUFET project addresses these challenges by developing a novel, label-free biosensing platform based on miniaturized graphene field-effect transistors (gFETs). These advanced sensors are capable of real-time detection of intact viral particles, not just fragments, providing a new level of clinical relevance. The FLUFET system integrates innovations in graphene surface chemistry, bioconjugation, predictive modeling, and pressure-controlled microfluidics, aiming to create a portable, automated, and highly selective platform adaptable to a wide range of viral pathogens.
Scientifically, FLUFET merges advances in materials science, microfluidics, and biosensing into a cohesive system. Societally, it promises faster outbreak detection, reduced dependence on central labs, and greater healthcare accessibility in both high- and low-resource settings. Its modular design allows for rapid adaptation to newly identified viruses, supporting global pandemic preparedness.ource environments. The modular nature of the system allows rapid adaptation to emerging pathogens, potentially shortening the time from pathogen identification to deployment of a diagnostic test.
The FLUFET project addresses these challenges by developing a novel, label-free biosensing platform based on miniaturized graphene field-effect transistors (gFETs). These advanced sensors are capable of real-time detection of intact viral particles, not just fragments, providing a new level of clinical relevance. The FLUFET system integrates innovations in graphene surface chemistry, bioconjugation, predictive modeling, and pressure-controlled microfluidics, aiming to create a portable, automated, and highly selective platform adaptable to a wide range of viral pathogens.
Scientifically, FLUFET merges advances in materials science, microfluidics, and biosensing into a cohesive system. Societally, it promises faster outbreak detection, reduced dependence on central labs, and greater healthcare accessibility in both high- and low-resource settings. Its modular design allows for rapid adaptation to newly identified viruses, supporting global pandemic preparedness.ource environments. The modular nature of the system allows rapid adaptation to emerging pathogens, potentially shortening the time from pathogen identification to deployment of a diagnostic test.
WP1: Biomolecule–Virus Interaction Modeling. A comprehensive virus–receptor interaction map was developed, cataloguing over 700 virus-human receptor pairs. This database, ranked by zoonotic risk and WHO priorities, supports intelligent receptor selection. A multi-scale simulation framework was created to model receptor–virus dynamics on graphene under flow conditions, revealing that polymer brush coatings improve receptor stability and selectivity.
WP2: gFET Surface Engineering. A standardized functionalization protocol using PBASE was established for stable non-covalent bioconjugation of antibodies and receptors (e.g. ACE2, HL257, CR3022). The project transitioned from GFET-S20 to miniGFET arrays, enhancing signal stability and reproducibility. Internal gold/platinum gate electrodes were replaced with external Ag/AgCl gates for improved measurement reliability. Dummy viruses were also produced for biosensor testing, and surface passivation strategies using BSA and PEG were initiated to reduce non-specific binding.
WP3: Microfluidic Integration. Custom-designed microfluidic flow cells were developed to integrate gFETs and optical microscopy, enabling control of shear forces for virus manipulation. Finite Element Modeling (FEM) optimized these forces to allow selective detachment of viral particles, mimicking realistic biological interactions. The modular, pressure-driven system supports rapid and reproducible liquid handling. Initial issues with polystyrene particles were resolved by switching to silica-based fluorescent nanoparticles.
WP4: System Testing and Validation. A first prototype of the complete sensing system (i.e. without microfluidic part) was assembled and partially validated. Stocks of SARS-
CoV-2 (CoV-2), H1N1, and VSV viruses were successfully produced. MiniGFETs functionalized with ACE2 showed selective detection of SARS-CoV-2 Spike protein, confirming system functionality. A working reader device prototype was also constructed and tested in the labies. Key outcomes include the successful construction and laboratory testing of the first reader device prototype.
WP2: gFET Surface Engineering. A standardized functionalization protocol using PBASE was established for stable non-covalent bioconjugation of antibodies and receptors (e.g. ACE2, HL257, CR3022). The project transitioned from GFET-S20 to miniGFET arrays, enhancing signal stability and reproducibility. Internal gold/platinum gate electrodes were replaced with external Ag/AgCl gates for improved measurement reliability. Dummy viruses were also produced for biosensor testing, and surface passivation strategies using BSA and PEG were initiated to reduce non-specific binding.
WP3: Microfluidic Integration. Custom-designed microfluidic flow cells were developed to integrate gFETs and optical microscopy, enabling control of shear forces for virus manipulation. Finite Element Modeling (FEM) optimized these forces to allow selective detachment of viral particles, mimicking realistic biological interactions. The modular, pressure-driven system supports rapid and reproducible liquid handling. Initial issues with polystyrene particles were resolved by switching to silica-based fluorescent nanoparticles.
WP4: System Testing and Validation. A first prototype of the complete sensing system (i.e. without microfluidic part) was assembled and partially validated. Stocks of SARS-
CoV-2 (CoV-2), H1N1, and VSV viruses were successfully produced. MiniGFETs functionalized with ACE2 showed selective detection of SARS-CoV-2 Spike protein, confirming system functionality. A working reader device prototype was also constructed and tested in the labies. Key outcomes include the successful construction and laboratory testing of the first reader device prototype.
· Beyond immunosensors: Unlike most biosensors that rely on antibodies as recognition elements, FLUFET has advanced the field by developing a sensor that uses human cell receptors, the natural viral entry points, as biorecognition molecules, enabling more biologically relevant and potentially broader virus detection.
· Validated Surface Functionalization: Protocols confirmed by Raman spectroscopy and XPS allow precise receptor and antibody attachment to graphene.
· MiniGFET Arrays: These offer enhanced reproducibility and signal quality over previous gFET designs.
· Dummy Virus Testing: Nanoparticles functionalized with viral proteins simulate real viruses for safe, controlled sensor validation.
· Custom Microfluidics: Integration with FEM-guided shear control enables tunable detachment and binding conditions, rarely implemented in biosensing.
· Open Simulation Tools: FLUFET developed and released open-source codes (e.g. Graft Flow) to model sensor–virus interactions.eyond existing technologies by integrating advanced modeling, novel materials engineering, precision microfluidics, and biological validation into a cohesive, next-generation biosensing platform.
· Validated Surface Functionalization: Protocols confirmed by Raman spectroscopy and XPS allow precise receptor and antibody attachment to graphene.
· MiniGFET Arrays: These offer enhanced reproducibility and signal quality over previous gFET designs.
· Dummy Virus Testing: Nanoparticles functionalized with viral proteins simulate real viruses for safe, controlled sensor validation.
· Custom Microfluidics: Integration with FEM-guided shear control enables tunable detachment and binding conditions, rarely implemented in biosensing.
· Open Simulation Tools: FLUFET developed and released open-source codes (e.g. Graft Flow) to model sensor–virus interactions.eyond existing technologies by integrating advanced modeling, novel materials engineering, precision microfluidics, and biological validation into a cohesive, next-generation biosensing platform.