Curved single crystals provide variable, but well-defined surface structures.

The focus throughout this thesis will be on gathering fundamental studies of the detailed structure and composition of the electrode/electrolyte interface effect on the rate and mechanism of key electrocatalytic reactions.

In most applications, electrocatalysts exhibit a large surface area to volume ratio, for example using nanoparticles.

Promotor: M.T.M. Koper, Co-Promotor: L.B.F. Juurlink

X-Ray Diffraction (XRD), Nuclear Magnetic Resonance (NMR) and Cryo-electron microscopy (Cryo-EM) are the three main methods for solving structures of macromolecules.

The research presented in this thesis makes use of small molecules (as H2 , D2 and O2 ) on well-defined single crystal surfaces (flat Pt(111), flat Cu(211) and curved Pt(111)) to elucidate the role of surface structure and degrees of freedom in the reactant in specific surface reactions.

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.

Promotor: J.P. Abrahams, Co-promotor: T. Grüne

Heterogeneous catalysis is essential to many industrial applications. These catalysts are often comprised of supported nanoparticles, which contain various different surface sites.

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.

Promotor: J. Zaanen, Co-Promotor: V. Juricic

CRANK is a novel suite for automated macromolecular structure solution and uses recently developed programs for substructure detection, refinement, and phasing.

This paper describes various components of the macromolecular crystallographic refinement program REFMAC5, which is distributed as part of the CCP4 suite. REFMAC5 utilizes different likelihood functions depending on the diffraction data employed (amplitudes or intensities), the presence of twinning…

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

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

John van Noort

Biomolecular X-ray structures typically provide a static, time- and ensemble-averaged view of molecular ensembles in crystals. In the absence of rigid-body motions and lattice defects, B-factors are thought to accurately reflect the structural heterogeneity of such ensembles.

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

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

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.

The local ordering of atoms at the surface of a metallic particle determines its catalytic activity and selectivity. As energy systems of the future will be based on efficient catalytic conversion of small molecules in closed cycles, we study how structural effects of catalysts can be used to our ad…

Promotores: Prof.dr. D. Bouwmeester, Prof.dr. A. Fiore (TU Eindhoven)

The goal is to reduce single use coffee cup use both at the university cafés and cofee machines.

An Ancient Egyptian System of Workmen’s Identity Marks

Visualization of biomolecules in living cells by tagging with gold nanoparticles.

PhD Defence

PhD Defence

LCD screens use liquid crystals which have a high degree of order, even though they form a fluid. A new theory maps out the interplay between order, temperature and symmetry. Publication in Physical Review X.

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…

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

We study cell-fate decision-making using embryonic stem cells as a model system. Stem cells integrate a large number of cues to direct their development into a great variety of cell types.

The research aim of the Catalysis and Surface Chemistry group headed by Prof. Marc Koper is to probe and understand chemical reactions on well-defined, mostly single crystalline, surfaces at the molecular level.

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

Do you want to be part of this unique programme, discuss cutting-edge topics of cyber security with other professionals, but do you not have time to enroll in this full master programme?

Promotor: Prof.dr. T. Hankemeier, Co-promotores: Heiko van der Linden, Paul Vulto

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.

The use-wear analysis of domestic implements provided new insights of the Single Grave Culture population in the Netherlands.

Promotor: M.T.M. Koper, Co-promotors: A.I. Yanson, L.B.F. Juurlink

Cathodic corrosion is a relatively unknown phenomenon that can severely etch metallic electrodes at cathodic (negative) potentials.

Metal complexes and 2D materials like graphene were combined to produce structures that can function as sensors.

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.

Promotor: M.A.G.J. Orrit

Promotor: Prof.dr. G.J. Kroes

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?

Microneedles represent promising tools for delivery of drugs to the skin. However, before these microneedles can be used in clinical practice, it is essential to understand the process of skin penetration by these microneedles.

This thesis consists of two main parts. The first part (Chapters 2 and 3) deals with a class of Markov process called Quasi-Skipfree (QSF) processes.

Leiden physicists have developed a way to address how accurately a superconducting single photon detector (SSPD) can be characterized by detector tomography. SSPDs are not fully understood, and tomography is a key element to determine how these devices detect light. A better understanding of these detectors…

Promotor: Christoph U. Keller, Co-promotores: Matthew A. Kenworthy, Frans Snik