Investigation of the fundamental spectral properties of emitting probes used in bionanosciences on the single molecule level

Dr. Christian Blum (BPE group)

Background

Over the last decade great advances were achieved towards the investigation of nature at the ultimate miniaturization level, the single molecule level. Especially in bio- and life sciences there is a strong trend towards the analysis on the single molecule level. One important direction of this research is the use of luminescent single molecules or single particles as reporters or probes in in vitro and even in vivo systems. Single molecule fluorescence detection is used for various applications, e.g. to follow and localize labeled target proteins, whereas multiplexing techniques become more and more important, and as local probes to report on the nanoenvironment of the single chromophore. Because of the outstanding potential of fluorescence microscopy great efforts are made to design new probes and to optimize known probes.

When analyzing the emission of a very low number of molecules or even a single molecule at a time individual properties usually hidden by bulk averaging become visible, e.g. the well known “blinking” of single fluorescent molecules.

Objective

The aim of the project is to investigate the fundamental spectral single particle properties of luminescent probes used in bionanosciences by room temperature single molecule spectroscopy. Opposed to the analysis of just the emission intensity of single particles over time, the focus of the project is clearly the analysis of the spectral properties of single particles since the spectral behaviour of single particles and molecules is widely unknown.

Probes to be analyzed include already established emitters as fluorescent proteins (VFPs) and quantum dots (QDots) as well as new systems that are developed at the moment as the new class of luminescent upconversion particles.