Paul Ruijgrok

Journal Articles

• Damping of Acoustic Vibrations of Single Gold Nanoparticles Optically Trapped in Water NANO LETTERS Ruijgrok, P. V., Zijlstra, P., Tchebotareva, A. L., Orrit, M. 2012; 12 (2): 1063-1069

  Abstract

  We combine ultrafast pump-probe spectroscopy with optical trapping to study homogeneous damping of the acoustic vibrations of single gold nanospheres (80 nm diameter) and nanorods (25 nm diameter by 60 nm length) in water. We find a significant particle-to-particle variation in damping times. Our results indicate that vibrational damping occurs not only by dissipation into the liquid, but also by damping mechanisms intrinsic to the particle. Our experiment opens the study of mechanisms of intrinsic mechanical dissipation in metals at frequencies 1-1000 GHz, a range that has been difficult to access thus far.

  View details for DOI 10.1021/nl204311q

  View details for Web of Science ID 000299967800090

  View details for PubMedID 22251064

• Brownian Fluctuations and Heating of an Optically Aligned Gold Nanorod PHYSICAL REVIEW LETTERS Ruijgrok, P. V., Verhart, N. R., Zijlstra, P., Tchebotareva, A. L., Orrit, M. 2011; 107 (3)

  Abstract

  We present the first quantitative measurements of the torque exerted on a single gold nanorod in a polarized three-dimensional optical trap. We determined the torque both by observing the time-averaged orientation distribution and by measuring the dynamics of the rotational brownian fluctuations. The measurements are in good agreement with calculations, where the temperature profile around the hot nanorod gives rise to a reduced, effective viscosity. The maximum torque on a 60??nm×25??nm nanorod was 100??pN·nm, large enough to address single-molecule processes in soft and biological matter.

  View details for DOI 10.1103/PhysRevLett.107.037401

  View details for Web of Science ID 000292597400024

  View details for PubMedID 21838403

• Making gold nanoparticles fluorescent for simultaneous absorption and fluorescence detection on the single particle level PHYSICAL CHEMISTRY CHEMICAL PHYSICS Gaiduk, A., Ruijgrok, P. V., Yorulmaz, M., Orrit, M. 2011; 13 (1): 149-153

  Abstract

  We demonstrate a simple way of making individual 20 nm gold nanoparticles fluorescent (with a fluorescence quantum yield of about 10(-6)) in glycerol. Gold NPs prepared in such a way have bright fluorescence for a long time under moderate excitation, and their fluorescence remains when the solvent is exchanged to water. We propose to use these nanoparticles as a calibration standard for simultaneous detection of fluorescence and absorption (by means of photothermal detection), and experimentally demonstrate the theoretically predicted shift in axial positions of these signals. Simultaneous absorption and fluorescence detection of such stable labels makes them attractive for multidimensional tracking and screening applications.

  View details for DOI 10.1039/c0cp01389g

  View details for Web of Science ID 000285099800017

  View details for PubMedID 21042602

• Room-Temperature Detection of a Single Molecule's Absorption by Photothermal Contrast SCIENCE Gaiduk, A., Yorulmaz, M., Ruijgrok, P. V., Orrit, M. 2010; 330 (6002): 353-356

  Abstract

  So far, single-molecule imaging has predominantly relied on fluorescence detection. We imaged single nonfluorescent azo dye molecules in room-temperature glycerol by the refractive effect of the heat that they release in their environment upon intense illumination. This photothermal technique provides contrast for the absorbing objects only, irrespective of scattering by defects or roughness, with a signal-to-noise ratio of ~10 for a single molecule in an integration time of 300 milliseconds. In the absence of oxygen, virtually no bleaching event was observed, even after more than 10 minutes of illumination. In a solution saturated with oxygen, the average bleaching time was of the order of 1 minute. No blinking was observed in the absorption signal. On the basis of bleaching steps, we obtained an average absorption cross section of 4 angstroms(2) for a single chromophore.

  View details for DOI 10.1126/science.1195475

  View details for Web of Science ID 000282986700036

  View details for PubMedID 20947760

• Spontaneous emission of a nanoscopic emitter in a strongly scattering disordered medium OPTICS EXPRESS Ruijgrok, P. V., Wuest, R., Rebane, A. A., Renn, A., Sandoghdar, V. 2010; 18 (6): 6360-6365

  Abstract

  Fluorescence lifetimes of nitrogen-vacancy color centers in individual diamond nanocrystals were measured at the interface between a glass substrate and a strongly scattering medium. Comparison of the results with values recorded from the same nanocrystals at the glass-air interface revealed fluctuations of fluorescence lifetimes in the scattering medium. After discussing a range of possible systematic effects, we attribute the observed lengthening of the lifetimes to the reduction of the local density of states. Our approach is very promising for exploring the strong threedimensional localization of light directly on the microscopic scale.

  View details for Web of Science ID 000276002500109

  View details for PubMedID 20389659

• Detection limits in photothermal microscopy Chem. Sci. Gaiduk A, Ruijgrok PV, Yorulmaz M, Orrit M 2010; 1 (3): 343-350
• Probing the acoustic vibrations of single gold nanoparticle by ultrashort laser pulses Laser Photonics Rev. Tcheborateva AL, Ruijgrok PV, Zijlstra P, Orrit M 2010; 4 (4): 581-597
• Acoustic and Optical Modes of Single Dumbbells of Gold Nanoparticles CHEMPHYSCHEM Tchebotareva, A. L., van Dijk, M. A., Ruijgrok, P. V., Fokkema, V., Hesselberth, M. H., Lippitz, M., Orrit, M. 2009; 10 (1): 111-114

  View details for DOI 10.1002/cphc.200800289

  View details for Web of Science ID 000262870500015

  View details for PubMedID 18688828