Publication on Matrix-Induced Linear Stark Effect

Cover Feature of ChemPhysChem issue 1/2019

Amin’s and Zoran’s work on the linear Stark effect has been published in ChemPhysChem!

The article, also featured as a cover of the journal, presents the first demonstration of a large linear Stark effect by using a novel strategy of matrix-induced symmetry breaking in otherwise centro-symmetric DBT guest molecules. The article is published in a collaboration with colleagues from the Institute of Physics of Polish Academy of Sciences.

More description can be read in the LION press release.

Congratulations to all the authors!

New publication on single-emitter two-photon-excited fluorescence

Our latest work on two-photon-excited fluorescence of single quantum dots is now published in ACS Photonics!

Individual gold nanorods are used to enhance the fluorescence emission of a single quantum dot when it is excited by the absorption of two low energy photons.

In a nutshell, we showed more than 10000-fold enhanced fluorescence of a single semiconductor quantum dot using a two-photon-excitation scheme. The high enhancement of this nonlinear effect arises mainly from the local field amplification at the tip of the nanorod. For more details, see the paper.

Congratulations to all the authors!

New publication in Nano Letters

We are proud of our research! Our latest publication on nanothermometry is in the top-10 most-read NanoLetters papers of the month!

(left) Anti-Stokes emission spectra of an individual gold nanorod excited in resonance with different laser powers. The lines are fits using our model. (right) Extracted temperature of the nanorod for several excitation powers.

Briefly, in this paper we present a method to extract the absolute temperature of an individual gold nanorod by measuring the anti-Stokes emission spectra. We present a simple model to interpret the data and we show that we can achieve 4K accuracy in the temperature determination with only 180s integration time.

Congratulations to the authors!


NGL lecture by Michel Orrit

On 18 January 2018, Michel Orrit will give a lecture as part of the NGL lecture series (Natuurwetenschappelijk Gezelschap Leiden)

Single molecules and single gold nanoparticles in the spotlight

Michel Orrit will present several optical methods giving access to signals from single molecules and single gold nanoparticles. Single gold nanoparticles are interesting because of their strong interaction with light mediated by their plasmon resonance, and because they are chemically and photochemically very stable. The experiments are based on fluorescence or photoluminescence, scattering, absorption detected by photothermal contrast, purely refractive effects leading to shifts of the plasmon resonance, or plasmon-enhanced fluorescence of weak emitters. Some chosen results will demonstrate the power of these experiments to explore the nanoworld in a non-invasive way.


De Sitterzaal
Huygens Laboratory
Leiden University
Niels Bohrweg 2
2333 CA Leiden


19:30 lecture hall open
19:45 lecture
20:30 break
20:45 continuation of the lecture
21:15 End

Registration form
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Spinoza Prize awarded to Michel Orrit

2017 Spinoza prize winners – left-to-right: Alexander van Oudenaarden, Eveline Crone, Albert Heck en Michel Orrit (photo: NWO/Ivar Pel)

On 16 June 2017, the Netherlands Organisation for Scientific Research NWO announced that Professor Michel Orrit is among the winners of this year’s Spinoza prize.

The Spinoza Prize is the highest Dutch scientific award, and comes with a grant of 2.5 million euro to be spent on further scientific research. This high honour was awarded to Prof. Orrit in recognition of his seminal work in the field of single-molecule spectroscopy.

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