Princeton Instruments
Scientific Imaging Industrial Imaging spectroscopy X-Ray Acton Optics

Single Molecule Fluorescence

PhotonMAX helps researchers uncover the relationship between blinking statistics and ligand coverage on a single Qdot surface. The results are published in a recent cover paper in The Journal of Physical Chemistry

Recently, M. Barnes et al from The George Richason, Jr. Chemistry Research Laboratory, Department of Chemistry and Department of Polymer Science & Engineering, University of Massachusetts used PI/Acton's PhotonMAX: 512B camera to perform correlated single molecule fluorescence measurements on CdSe quantum dots. Results showed, for the first time, blinking statistics are related to the ligand coverage on the Qdot surface. In one finding, they report that the completely covered (~25 ligands) CdSe-OPV nanostructures showed complete blinking suppression. PhotonMAX provided needed sensitivity to capture images with 100msec to 2 sec exposure times over 1000 seconds. They also used Princeton Instruments PIXIS: 400B with SP2150i spectrograph to perform spectroscopy measurements as well.

Researchers explore the hidden heterogeneity of chemical systems by measuring the behavior of single molecules rather than the average over the ensemble. Complex systems like biological molecules and condensed matter exhibit this heterogeneity because of local environments, or conformational states. 



Single molecule fluorescence image captured using Cascade EMCCD camera 

Solutions from Princeton Instruments

Princeton Instruments has pioneered the low-light, high-speed imaging technology, which are the primary requirements for single molecule fluorescence applications. Princeton Instruments also designed the first high-performance, high-frame rate ICCD camera (I-PentaMAX) for single molecule applications, which was, for a long period, the gold standard for low-light cameras. For example, the on/off blinking and switching behavior of the single molecules was first described by Dickson, Cubitt, Tsien, Moerner etc., all using the I-PentaMAX. Recent arrival of EMCCD cameras has further expanded the capabilities of the detection systems with single photon sensitivity at very high frame rates. Features include:  

  • Deep cooled EMCCD cameras for single photon sensitivity 
  • Traditional CCDs for high-dynamic range applications 
  • Ultra-high frame rate for single molecule tracking applications 
  • Real time frame access for feedback control systems
  • Ultra-precise active bias and EM gain calibration

Recommended Products:

ProEM

  • Deep cooling with lifetime vacuum guarantee
  • Back-illumination and electron multiplication gain for single photon sensitivity
  • Real-time frame access capability
  • Fast, absolute EM gain calibration with built-in precision light source
  • Ultra-stable bias for long sequences

Cascade

  • Cascade: 128+ provides >510 frames-per-second; ideal for adaptive optics.
  • Cascade: 1K offers high-resolution and good blue response.
  • Back/front-illumination and electron multiplication gain for single photon sensitivity. 
  • Real time frame access capability.