Congratulations, Dr Carattino!

Congratulations to Dr Aquiles Carattino, who successfully defended his PhD thesis titled “Gold Nanorod Photoluminescence — Applications to Imaging and Temperature Sensing” on Thursday 9 March 2017 at Leiden University’s Academy Building in the traditional manner.

Aquiles Carattino (ctr), flanked by his paranymphs Martín Caldarola (l) and Pravin Kumar (r)

New publication on single-molecule electrochemistry

We are proud of our recent publication on single-molecule electrochemistry using enhanced fluorescence as readout.

At both ends of the nanorod (yellow), the incoming electromagnetic field of light is amplified by a factor 300 (red spots). If a molecule (blue dots) is situated there, its fluorescent signal is gets 500 times stronger.

We used gold nanorods as nanoatennas to reveal single-molecules of a redox sensitive dye, Methylene Blue, and studied the electrochemical properties of this molecule one by one.

Leiden University’s Press release can be found here and a comment at here

Publication: M.Sc. Weichun Zhang, Dr. Martín Caldarola, M.Sc. Biswajit Pradhan, Prof. Dr. Michel Orrit, ‘Gold Nanorod-Enhanced Fluorescence Enables Single-Molecule Electrochemistry of Methylene Blue‘, Angewandte Chemie

Michel Orrit wins Edison Volta Prize

The European Physical Society (EPS) has awarded the prestigious Edison Volta Prize to Professor Michel Orrit. The prize, which is awarded annually by the EPS “to promote excellent research and achievement in physics”, was awarded to Orrit

for “seminal contributions to optical science, to the field of single-molecule spectroscopy and imaging (first single molecule detection by fluorescence and first optical detection of magnetic resonance in single molecule) and for pioneering investigations into the photoblinking and photobleaching behaviors of individual molecules at the heart of many current optical super-resolution experiments.”

Edison Volta Prize

Within the past year, Michel Orrit has also been awarded the Physica Prize by the Dutch Stichting Physica and the Nederlandse Natuurkundige Vereniging as well as the Grand Prix Léon Brillouin by the Société Française d’Optique.

Read the announcement on the website of the Leiden Institute of Physics.

Michel Orrit wins the Physica Prize 2016

The Nederlandse Natuurkundige Vereniging and Stichting Physica have announced that Michel Orrit will receive the national Physica Prize 2016. Michel Orrit is honoured with the prize for his groundbreaking work on single molecule spectroscopy. In the mid ‘80s, Orrit came to the realization that it should be possible to optically detect a single molecule. A few years later, in 1990, he indeed became the first one to detect the fluorescence signal of one molecule.

Last year, the Nobel Prize in Chemistry was awarded to Betzig, Hell and Moerner for the development of super-resolved fluorescence microscopy. The Nobel Committee’s description of the scientific background clearly showed the groundbreaking significance of Orrit’s experiment as the basis for the super-resolution techniques that were established afterwards. Moerner measured a single molecule slightly before Orrit, using absorption, but Orrit’s measurement using fluorescence produced much less background noise and became the standard in this scientific field.

Michel Orrit wins Physica Prize

Faster computers with a GPS for electrons?

To build faster computers and larger memories physicists need to know the exact position of electrons in microcircuits. Prof. Michel Orrit and colleagues want to build an apparatus for that, with the help of a 0.5 MEuro investment from the Stichting Fundamenteel Onderzoek der Materie (FOM).

Electronic GPS: simultaneous measurement of several electrons:

Prof dr Michel Orrit and Dr Sanli Faez, in collaboration with Dr Sense Jan van der Molen, have proposed a new platform to detect the charge distribution at the nanoscale. They even expect to be able to detect elementary particles, electrons, simulataneously, which is not possible with scanning probe techniques.

Schematic principle of the technique

Organic dye molecules are immobilized over a network of gold nanoparticles. Charging and discharging of hte particles modifies electric fields, thereby shifting the resonance frequency (color) of individual molecules. These frequencies are read with high accuracy through high-resolution laser spectroscopy.

Nanometer resolution

Instead of a single large reading device, the team will use a number of organic molecules as independent nanodetectors. They can be placed on top of a chip with gold nanoparticles and used to map the charge distribution of the chip. This is made possible by the large sensitivity of the molecular optical transition to spectral shifts caused by electric fields stemming from individual charges in the molecule’s environment. The resolution expected should be around a nanometer.

Faster computers

Orrit: “Our experiment can be useful to devise new methods for information storage and transfer, and to analyze scales smaller than current semiconductor transistors. This can in turn lead to faster computers with a larger storage capacity. It will help researchers get new insights into the physics of electronic components at such small scales.

About the grant

Projectruimte proposals of FOM funds small-scale fundamental projects with an innovative character and with a clear scientific, industrial or societal relevance. FOM had a budget of 10 million Euro for 2015, from which 3 million were earmarked for projects within the Sectorplan Physics and Chemistry.

Michel Orrit awarded the Grand Prix SFO Léon Brillouin

Grand Prix SFO Léon Brillouin

The French Optics Society (SFO) has announced the winners of its biennial Grand Prix SFO Léon Brillouin. Professor Michel Orrit from the Leiden Institute of Physics (LION) is one of two people that receive the honour this year. The prize was established to honor the memory of physicist Léon Brillouin (1889-1969), whose various works have profoundly influenced the development of optics. The Grand Prix is awarded every odd year, after a jury has selected the winners.

Single-Molecule Microscopy and Spectroscopy: Faraday Discussion


14 – 16 September 2015
London, UK


Since their inception, optical detection and spectroscopy of single molecules have steadily expanded to an amazing variety of disciplines in natural sciences. Domains as varied as optical microscopy, quantum optics, nanophotonics, material science and soft-matter physical chemistry all have benefited from the new, average-free insights provided by the optical isolation of single molecules, quantum dots, metal nanoparticles, and other nanometre-sized objects. The techniques themselves have also made spectacular progress with the developments in super-resolution microscopy, time-resolved measurements, absorption-based detection, combination with mechanical or electrical manipulation and recording, live-cell imaging, and metal nanoparticle-enhanced phenomena.

At the chemistry-biology interface, new probes are needed for the study of various biological processes, most of them in live cells or even live organisms, but also for superresolution microscopy. The plasmonics-chemistry interface includes studies of catalysis, diffusion in soft materials and nanofluidics. At the border between quantum optics, plasmonics and physical chemistry, low-temperature spectroscopy experiments provide candidates for the manipulation of single spins as qubits, while new structures can be designed as nanoantennas to enhance molecular fluorescence and a broad variety of nonlinear optical processes.


  • Quantum optics and Plasmonics
    Single molecules have been used for many years as test systems in quantum optics, but the combination with plasmonics opens new routes for enhancement of excitation and emission
  • Probes and Sensors for Molecular Biophysics
    Plasmonic structures can be used as bright and stable labels, as rulers to probe dynamics, or as antennas to efficiently extract information from the nanoscale. These applications are particularly attractive in biophysics.
  • Superresolution and Imaging of Soft and Biological Matter
    Optical microscopy recently underwent a true revolution with superresolution imaging and a broad variety of nonlinear optical imaging modalities. The latter will be discussed in the restricted frame of single molecules and single objects.
  • Nonlinear optics and Coherence in Biophysics
    In relation with the previous subject, tailored light pulses open the way to manipulations of the quantum states of single molecules, and to the exploration of coherent effects in biological processes such as photosynthesis or electron transfer.


  • W E Moerner (Opening Lecturer)
    Stanford University
  • Stefan W. Hell (Closing Remarks)
    Max Planck Institute for Biophysical Chemistry
  • Xiaowei Zhuang
    Harvard University
  • Jens Michaelis
    University of Ulm
  • Ronald Hanson
    Delft University of Technology
  • Jörg Wrachtrup
    University of Stuttgart
  • Maxime Dahan
    Laboratoire Physico-Chimie, Institut Curie
  • Brahim Lounis
    Université Bordeaux 1
  • Lukas Novotny
    ETH Zurich
  • Haw Yang
    Princeton University

Registration open for the Casimir Spring School

“Sun, Sailing and Science”- Casimir Spring School in Arnemuiden

Registration open here.

Dear Casimir PhD-students and Postdocs, you are all invited for the 5th Casimir Spring School, 6-8 May in Arnemuiden, in the province of Zeeland, the Netherlands! The Spring School is only intended for PhD-students and postdocs from the Kavli Institute in Delft and the LION in Leiden. This means that there will be no staff present in Arnemuiden: apart from the keynote lectures and workshops, all talks will be given by Casimir PhD-students and postdocs only. The broad spectrum of research themes within the Casimir Research School will be covered by three thematic plenary sessions, each with one external keynote speaker. During each session, six students will be given the opportunity to give a short talk (20 minutes) and discuss their own work with the group.

This year the sessions will be ‘Biophysics / soft condensed matter’, ‘Solid State Physics’ and ‘Quantum Optics’. The keynote speakers for these sessions are: dr. Harald Janovjak (Biophysics / soft condensed matter, IST Austria), prof. Amir Yacoby (Solid State Physics, Harvard University, USA), and -still to be confirmed- dr. Vadim Makarov (University of Waterloo, Canada). We have invited the external speakers to join us during the full three days.

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