A5076879004- Microfluidic and Bio-sensing Technologies
- Nanopore and Nanochannel Transport Studies
- SARS-CoV-2 and COVID-19 Research
- Microfluidic and Capillary Electrophoresis Applications
- SARS-CoV-2 detection and testing
- RNA Research and Splicing
- Advanced Fluorescence Microscopy Techniques
- Surfactants and Colloidal Systems
- Parkinson's Disease Mechanisms and Treatments
- Advanced biosensing and bioanalysis techniques
- RNA modifications and cancer
- Advanced Polymer Synthesis and Characterization
- Electrostatics and Colloid Interactions
- biodegradable polymer synthesis and properties
- Long-Term Effects of COVID-19
- 3D Printing in Biomedical Research
- Gold and Silver Nanoparticles Synthesis and Applications
- Protein Interaction Studies and Fluorescence Analysis
- RNA Interference and Gene Delivery
- Viral Infectious Diseases and Gene Expression in Insects
- Petroleum Processing and Analysis
- Endoplasmic Reticulum Stress and Disease
- Lipid Membrane Structure and Behavior
- Polymer Surface Interaction Studies
- Pickering emulsions and particle stabilization
University of Cambridge
2017-2024
ETH Zurich
2024
The detection of proteins is central importance to biomolecular analysis and diagnostics. Typical immunosensing assays rely on surface-capture target molecules, but this constraint can limit specificity, sensitivity, the ability obtain information beyond simple concentration measurements. Here we present a surface-free, single-molecule microfluidic sensing platform for direct digital protein biomarker in solution, termed immunosensor assay (DigitISA). DigitISA based microchip electrophoretic...
Abstract Several RNA binding proteins involved in membraneless organelles can form pathological amyloids associated with neurodegenerative diseases, but the mechanisms of how this aggregation is modulated remain elusive. Here we investigate heterotypic protein–RNA interactions modulate condensation and liquid to amyloid transition hnRNPA1A, a protein amyothropic lateral sclerosis. In absence RNA, formation condensates promotes hnRNPA1A fibrils are localized at interface condensates. Addition...
Oligomeric species arising during the aggregation of α-synuclein are implicated as a major source toxicity in Parkinson's disease, and thus potential drug target. However, both their mechanism formation role largely unresolved. Here we show that, at physiological pH absence lipid membranes, aggregates form by secondary nucleation, rather than simple primary that this process is enhanced agitation. Moreover, using combination single molecule bulk level techniques, identify nucleation on...
Abstract Effective public-health measures and vaccination campaigns against SARS-CoV-2 require granular knowledge of population-level immune responses. We developed a Tripartite Automated Blood Immunoassay (TRABI) to assess the IgG response ectodomain receptor-binding domain spike protein as well nucleocapsid SARS-CoV-2. used TRABI for continuous seromonitoring hospital patients healthy blood donors (n=72’222) in canton Zurich from December 2019 2020 (pre-vaccine period). Seroprevalence...
The clinical outcome of SARS-CoV-2 infections, which can range from asymptomatic to lethal, is crucially shaped by the concentration antiviral antibodies and their affinity targets. However, polyclonal antibody responses in plasma difficult measure. Here we used microfluidic profiling (MAAP) determine aggregate affinities concentrations anti-SARS-CoV-2 samples 42 seropositive individuals, 19 were healthy donors, 20 displayed mild symptoms, 3 critically ill. We found that dissociation...
Effective public health measures against SARS-CoV-2 require granular knowledge of population-level immune responses. We developed a Tripartite Automated Blood Immunoassay (TRABI) to assess the IgG response three proteins. used TRABI for continuous seromonitoring hospital patients and blood donors (n = 72′250) in canton Zurich from December 2019 2020 (pre-vaccine period). found that antibodies waned with half-life 75 days, whereas cumulative incidence rose 2.3% June 12.2% mid-December 2020. A...
We develop and present a one-pot sandwich immunoassay (termed oneSTEP) to detect target biomolecules in complex biological fluids based on programmable zwitterionic polymer coacervates. design these coacervates selectively recruit analytes with ultralow nonspecific adsorption. show that dynamic compartmentalization combined local enrichment delivers rapid wash-free high specificity signal-to-noise ratio. The fluorescence-based readout is performed using standard microscopy methods flow...
Living systems are characterized by their spatially highly inhomogeneous nature which is susceptible to modify fundamentally the behavior of biomolecular species, including proteins that underpin biological functionality in cells. Spatial gradients chemical potential known lead strong transport effects for colloidal particles, but effect on molecular scale species such as has remained largely unexplored. Here, we improve existing diffusiophoresis microfluidic technique measure protein real...
Abstract Oligomeric species arising during aggregation of α-synuclein are proposed to be a major source toxicity in Parkinson’s disease, and thus potential drug target. However, their mechanism formation role largely unresolved. Here we first show that, at physiological pH, aggregates by secondary nucleation, rather than fragmentation, that this process is enhanced agitation. Moreover, using combination single molecule bulk level techniques, identify nucleation on the surfaces existing...
Many biological molecules are by their nature amphiphilic and have the ability to act as surfactants, stabilizing interfaces between aqueous immiscible oil phases. In this paper, we explore adsorption kinetics of surfactin, a naturally occurring cyclic lipopeptide, at hexadecane/water compare contrast its behaviour with that synthetic alkyl benzene sulfonate isomers, through direct measurements changes in interfacial tension upon surfactant adsorption. We access millisecond time resolution...
Abstract 3D scaffolds in the form of hydrogels and microgels have allowed for more native cell‐culture systems to be developed relative flat substrates. Native biological tissues are, however, usually spatially inhomogeneous anisotropic, but regulating spatial density at microscale mimic this inhomogeneity has been challenging achieve. Moreover, development biocompatible synthesis approaches protein‐based remains challenging, typical gelation conditions include UV light, extreme pH,...
An approach relying on nanocavity confinement is developed in this paper for the sizing of nanoscale particles and single biomolecules solution. The approach, termed diffusional (NDS), measures particle residence times within nanofluidic cavities to determine their hydrodynamic radii. Using theoretical modeling simulations, we show that time nanocavities above a critical scale depends diffusion coefficient particle, which allows estimation particle's size. We demonstrate experimentally...
The analysis of nanoscopic species, such as proteins and colloidal assemblies, at the single-molecule level has become vital in many areas fundamental applied research. Approaches to increase detection time scales for single molecules solution without immobilizing them onto a substrate surface applying external fields are much sought-after. Here, we present an easy-to-implement versatile nanofluidics-based approach that enables increased observational-time scale material building blocks...
Abstract The clinical outcome of SARS-CoV-2 infections, which can range from asymptomatic to lethal, is crucially shaped by the concentration antiviral antibodies and their affinity targets. However, polyclonal antibody responses in plasma difficult measure. Here we used Microfluidic Antibody Affinity Profiling (MAAP) determine aggregate affinities concentrations anti-SARS-CoV-2 samples 42 seropositive individuals, 19 were healthy donors, 20 displayed mild symptoms, 3 critically ill. We...
Abstract The detection of proteins is central importance to biomolecular analysis and diagnostics, yet fundamental limitations due the surface-based nature most sensing approaches persist, limited improvements have been designed integrate multimodal information beyond concentration measurements. Here we present a single-molecule microfluidic platform for digital protein biomarker in solution, termed immunosensor assay (DigitISA). DigitISA based on microchip electrophoretic separation...
In article number 2000432, Tuomas P. J. Knowles and co-workers demonstrate a simple microfluidic approach to produce spatially inhomogeneous protein microgels, using versatile crosslinking regimes dynamics under biocompatible conditions. The microgels are promising candidates for extracellular matrix analogues tissue engineering scaffolds, which could open up new possibilities of micron-scaled constructs at the frontiers engineering/biology/materials interfaces.
Abstract Proteins constitute the molecular machinery of life and exert their biological function by interacting with other proteins, as well assembling into biomolecular complexes higher order structures. Characterizing sizes, interactions, assembly states proteins is thus key for understanding normal functional behavior elucidating aberrant processes interactions that can lead to dysfunction disease. However, physical characterization has remained a challenging problem due inherent...
Abstract Biomolecular condensates can affect enzymatic reactions by locally changing not only concentrations of molecules but also their environment. Since protein conformations differ between the dense and dilute phase, phase separation particularly modulate enzymes characterized a conformation-dependent activity. Here, we generate based on lipase from Bacillus thermocatenulatus , which exhibits an equilibrium closed, inactive state, open, active conformation. We show that activity enzyme...
Abstract Living systems are characterised by their spatially highly inhomogeneous nature which is susceptible to modify fundamentally the behaviour of biomolecular species, including proteins that underpin biological functionality in cells. Spatial gradients chemical potential known lead strong transport effects for colloidal particles, but effect on molecular scale species such as has remained largely unexplored. Here we demonstrate with microfluidic measurements individual can undergo...
Abstract The analysis of nanoscopic species, such as proteins and colloidal assemblies, at the single-molecule level has become vital in many areas fundamental applied research. Approaches to increase detection timescales for single molecules solution without immobilising them onto a substrate surface applying external fields are much sought after. Here we present an easy-to-implement versatile nanofluidics-based approach that enables increased observational-timescale biomacromolecules...
Abstract An approach relying on nano-cavity confinement is developed in this paper for the sizing of nanoscale particles and single biomolecules solution. The approach, termed diffusional (NDS), measures particle residence times within fluidic nano-cavities to determine their hydrodynamic radii. Using theoretical modeling simulation, we show that time above a critical timescale depends diffusion coefficient particle, which allows estimation particle’s size. We demonstrate experimentally...