Lifting the concentration limit of mass photometry by PEG nanopattering

Journal article

Mass photometry (MP) is a rapidly growing optical technique for label-free mass measurement of single biomolecules in solution. The underlying measurement principle provides numerous advantages over ensemble-based methods but has been limited to low analyte concentrations due to the need to uniquely and accurately quantify the binding of individual molecules to the measurement surface, which results in diffraction-limited spots. Here, we combine nanoparticle lithography with surface PEGylation to dramatically lower surface binding, resulting in a two-order magnitude improvement in the upper concentration limit associated with mass photometry. We demonstrate facile tunability of the degree of passivation, enabling measurements at increased analyte concentrations. These advances enable us to rapidly quantify protein- protein interactions in the high nM to low μM range, substantially expanding the application space of mass photometry.

Authors: Kratochvil, J; Asor, R; Helmi, S; Struwe, W; Kukura, P

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Nano Letters
• Volume: 24
• Issue: 33
• Pages: 10032–10039
• Publication date: 2024-07-01
• Acceptance date: 2024-06-25
• DOI: 10.1021/acs.nanolett.4c01667
• EISSN: 1530-6992
• ISSN: 1530-6984
• Language: English
• Keywords: protein - protein interactions; mass photometry; nanoparticle lithography; surface passivation