Direct digital sensing of protein biomarkers in solution

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung


  • Georg Krainer - , University of Cambridge (Autor:in)
  • Kadi L Saar - , University of Cambridge (Autor:in)
  • William E Arter - , University of Cambridge (Autor:in)
  • Timothy J Welsh - , University of Cambridge (Autor:in)
  • Magdalena A Czekalska - , University of Cambridge (Autor:in)
  • Raphaël P B Jacquat - , University of Cambridge (Autor:in)
  • Quentin Peter - , University of Cambridge (Autor:in)
  • Walther C Traberg - , University of Cambridge (Autor:in)
  • Arvind Pujari - , University of Cambridge (Autor:in)
  • Akhila K Jayaram - , University of Cambridge (Autor:in)
  • Pavankumar Challa - , University of Cambridge (Autor:in)
  • Christopher G Taylor - , University of Cambridge (Autor:in)
  • Lize-Mari van der Linden - , Professur für Zelluläre Biochemie (Autor:in)
  • Titus Franzmann - , Professur für Zelluläre Biochemie (Autor:in)
  • Roisin M Owens - , University of Cambridge (Autor:in)
  • Simon Alberti - , Professur für Zelluläre Biochemie, Biotechnologisches Zentrum (BIOTEC) (Autor:in)
  • David Klenerman - , University of Cambridge (Autor:in)
  • Tuomas P J Knowles - , University of Cambridge (Autor:in)


The detection of proteins is of central importance to biomolecular analysis and diagnostics. Typical immunosensing assays rely on surface-capture of target molecules, but this constraint can limit specificity, sensitivity, and the ability to obtain information beyond simple concentration measurements. Here we present a surface-free, single-molecule microfluidic sensing platform for direct digital protein biomarker detection in solution, termed digital immunosensor assay (DigitISA). DigitISA is based on microchip electrophoretic separation combined with single-molecule detection and enables absolute number/concentration quantification of proteins in a single, solution-phase step. Applying DigitISA to a range of targets including amyloid aggregates, exosomes, and biomolecular condensates, we demonstrate that the assay provides information beyond stoichiometric interactions, and enables characterization of immunochemistry, binding affinity, and protein biomarker abundance. Taken together, our results suggest a experimental paradigm for the sensing of protein biomarkers, which enables analyses of targets that are challenging to address using conventional immunosensing approaches.


FachzeitschriftNature communications
PublikationsstatusVeröffentlicht - 6 Feb. 2023

Externe IDs

PubMedCentral PMC9902533
Scopus 85147461210
ORCID /0000-0003-4017-6505/work/148146005



  • Biosensing Techniques/methods, Immunoassay, Biomarkers/analysis, Amyloid, Microfluidics/methods