In human cells, a meter-long DNA is condensed inside a micrometer-sized cell nucleus. Simultaneously, the genetic code must remain accessible for its replication and transcription to functional proteins.

This thesis is a collection of experimental attempts to enhance photoluminescence of fluorescent molecules and quantum dots with single gold nanorods (GNRs) and relevant applications.

Promotores: Prof.dr. G.W. Canters, Prof.dr. T.J. Aartsma

Since the early 1990s, one can isolate the optical signal of a single molecule and single-molecule spectroscopy has quickly grown into an important research field.

Single-molecule spectroscopy has become a powerful method for using organic fluorescent molecules in numerous applications.

Promotor: Prof.dr. M.A.G.J. Orrit

This thesis revolves around the electronic spectroscopy of molecules in the laboratory and the search for the carriers of the diffuse interstellar bands (DIBs).

Single-Molecule Microscopy (SMM) techniques constitute a group of powerful imaging tools that enable researchers to study the dynamic behavior of individual molecules.

Detecting nanoscopic objects plays an important role in nanoscience in particular, in the rapidly growing field of nanobiology. The forebear to modern super-resolution microscopy for single molecule investigation, is fluorescence microscopy.

The aim of the research presented in this thesis was to develop new methods forchallenging systems in liquid-state NMR using paramagnetic effects generated by thetwo-armed probe CLaNP-5.

Promotor: Prof.dr. T. Schmidt, Co-promotor: Dr. ir. S. J.T. van Noort

Promotores: G.W. Canters, T.J. Aartsma

In this thesis we investigated the ability of two-photon multifocal microscopy for single-molecule microscopy in live cells and organisms.

Intrigued by the way cells autonomously regulate their fate, we strive to understand and visualize cellular processes as the basis of Cell Signaling.

PhD defence

This thesis is about the study of hydrocarbons via infrared spectroscopy.

Gold nanorods are biocompatible nanoparticles that present an excellent two-photon signal that can be used to get high spatial resolution inside living cells. Gold nanorods are photostable and therefore can be followed inside cells for long time, with possible applications as trackers in live cells.

This thesis describes the implementation and on-sky demonstration of high-resolution integral-field spectroscopy for extreme adaptive optics systems that are used to find and characterize exoplanets.

A network combining 9 academic research groups and 4 collaborating industrial companies will train the next generation of PhD students and post-doctoral researchers, in developing and applying novel experimental and theoretical methods in the NMR spectroscopy of systems containing paramagnetic metals.…

This thesis focuses on the X-ray spectral analysis of merging galaxy clusters and the plasma code development for future high-resolution X-ray spectroscopy observations.

Visualising cell proteins without invasive techniques is possible with the help of fluorescence. During a lecture of the Natuurwetenschappelijk Gezelschap Leiden on 18 January, winner of the Spinoza Prize 2017 and founder of the field of single molecule optics Michel Orrit explained how this works.

In surface science there is great effort to move from studying simple, flat model surfaces in vacuum to investigating more complex model catalysts in gas environments (in situ). This thesis gives three examples of such studies using microscopy and spectroscopy.

Early time-resolved experiments by Frauenfelder on the ensemble of the kinetic rebinding of CO to myoglobin molecules resulted in a stretched exponential relaxa-tion due to a very large spread of the reaction rates of individual molecules.

An important award like the Spinoza Prize, the 'Dutch Nobel Prize', generates lots of media attention. An overview.

Promotor: M.A.G.J. Orrit

This thesis aims to improve the detection from ultra-weak single emitter by enhancing their emission properties with plasmonic nanostructures. We exploit the wet-chemically synthesized single crystalline gold nanorods (GNRs) as our basic frameworks in the whole studies, simply because of their unique…

Can we find new chemical and biological sensing routes on the edge and surface of graphene to improve the potential of graphene to act as a sensor?

Promotor: Prof.dr. H.L.V. Linnartz

Michel Orrit was awarded the Physica prize 2016 for his groundbreaking work on single molecule spectroscopy.

On September 12, Michel Orrit received his Spinoza prize in the Royal Theatre in The Hague from OCW Secretary of State Sander Dekker. With the award comes a budget of 2.5 million euro, to be spent freely on scientific research, and the coveted Spinoza statue. Orrit shared the honor with Eveline Crone…

Complex Organic Molecules (COMs) have been detected in objects across different stages of stellar evolution.

PhD defence

Hass

This thesis is about cosmological inflation and its relation to observations.

PhD defence

Bioactive Molecules is one of the four research themes of the Institute of Biology Leiden.

Optical detection of a single electron using a single molecule has never been done. Leiden physicist Michel Orrit and his team have now identified a molecule that is sensitive enough to detect an electron at a distance of hundreds of nanometers. The results are published as a cover article in ChemPh…

Ariadne Schmidt, Isabelle Devos and Julie de Groot provide you with refreshing insights concerning the study on urban singles in the period between 1200 and 1900.

It is partly thanks to Leiden professor Michel Orrit that we are today able to study individual molecules. He just missed winning a Nobel Prize, but is today the recipient of another important scientific award: NWO’s prestigious Spinoza Prize.

Promotor: Prof.dr. M. Ubbink

Until the 1990s, the only known planets were those in our Solar System. Three decades later, several thousand exoplanets have been discovered orbiting stars other than the Sun, and substantial efforts have been made to explore these strange new worlds through spectroscopic analyses of their atmosphe…

Our DNA molecules are packaged by proteins in compact structures. The aim of this project is to understand how modern gene editing techniques nevertheless get access to their target in the DNA.

Hot astrophysical plasma is ubiquitous in the Universe, from comets in our Solar system to the largest scale structures -- the cosmic web filaments. These hot plasmas, with the temperature of a few millions of degrees, are often observed in the X-ray wavelength range.

The single cell group (SCG) is part of the Metabolomics & Analytics Centre Our research is centered around developing innovating analytical methods tailored for small-volume, or single cell analysis to enable metabolomics-driven systems biology in personalized health strategies. We are always on…

Mechanobiology is a major area in biology, however, mechanics is currently a missing element in drug development pipelines. This has led to a high cost for the society. Mechanotoxicity of drugs often appears as a long-term side effect of drugs, and has led to removal of drugs from the market. Furthermore,…

Microbial Sciences' contribution to the Bioactive Molecules research theme is to discover new bioactive molecules and enzymes and unravel their mechanisms of action, regulatory networks, and the (bio)synthetic pathways required for their production.

Even a small quantum computer should be able to simulate exactly the properties and behaviour of new molecules. This would take chemistry to an entirely new level. Better solar panels, more powerful batteries, saving lots of energy in the chemical industry: the applications have the potential to transform…

Promotor: M. Ubbink, Co-promotor: G. Siegal