Events

Seminar of the Division of Biomedical Physicochemistry

Single-molecule applications based on wide-field upconversion microscopy

Dr. rer. nat. Hans-Heiner Gorris

Department of Biochemistry Masaryk University, Brno, CZ

Single molecule analysis has led to widespread research interest, and several schemes for single molecule sensing have been described in the literature [1]. Single molecule assays (or digital assays) however, do not necessarily lead to the highest analytical sensitivity, but rather enable new approaches to avoid background interference and a more robust readout [2]. In this lecture, I will present several digital assay approaches and highlight the advantages of UCNPs as background-free labels for a new generation of digital assays. Additionally, the lecture will cover the preparation, surface modification and characterization of UCNPs by agarose gel electrophoresis, and discuss the setup of our wide-field upconversion microscope. Based on immunohistochemistry, I will demonstrate that upconversion microscopy allows for a much higher imaging contrast as compared to standard fluorescence microscopy [3].

References:

1. Farka Z, Mickert MJ, Pastucha M, Mikušová Z, Skládal P, Gorris HH (2020): Advances in optical single-molecule detection:
En route to supersensitive bioaffinity assays. Angew. Chem. Int. Ed. 59 (27) 10746-10773.
2. Gorris HH, Soukka T (2022): What digital immunoassays can learn from ambient analyte theory: A perspective. Anal. Chem.
94 (16) 6073-6083.
3. Farka Z, Mickert MJ, Mikušová Z, Hlaváček A, Bouchalová P, Bouchal P, Skládal P, Gorris HH (2020): Surface design of
photon-upconversion nanoparticles for high-contrast immunocytochemistry. Nanoscale 12 (15) 8303-8313.