Good news for biophotonics

Karen A. Newman, karen.newman@photonics.com

Whether you follow the political or economic stories – or both – affecting life and business (if you have the stomach for it), you know that there hasn’t been a lot of good news lately. And questions abound regarding the impact of recent moves and markets on science and technology research. As the two worlds move toward steadier ground, researchers everywhere continue to push new diagnostic methods closer to clinical application.

One such arena is Förster resonance energy transfer (FRET) spectroscopy. For more than a decade, investigators have explored its potential for use with quantum dots in multiplexed diagnostics, noting the unique photophysical properties of the particles. In his feature, “Multiplexed Sensing with QD-based FRET,” news editor Gary Boas shares some of the latest research into QD-based FRET from around the world. The article begins on page 35.

Also in this issue:

“Fluorescence Imaging Progressing from Cells to Tissue,” by contributing editor Marie Freebody, explains that, although tissues and even whole animals are not as easily captured with fluorescence imaging as cells are, recent research and technological developments could change all that. The story starts on page 31.

In an article by Angela Goodacre and Dennis Donley of Olympus America Inc., we learn that windows of opportunity for research into dynamic cellular events and processes are opening, thanks to a multiphoton combo of intrinsic fluorescence and other label-free imaging modalities such as second-harmonic generation and coherent anti-Stokes Raman scattering. Read “Intrinsic Fluorescence Lights Up Cellular Components,” beginning on page 28.

Since its invention in the mid-1930s, the photomultiplier tube has been the principal detector for experiments involving a small number of photons. However, some disadvantages led researchers and systems designers to seek alternatives for single-photon detection. One result is the Geiger-mode silicon avalanche photodiode (G-SAPD), which enables single-photon detection with silicon APDs. Bernicy Fong of Excelitas Technologies Corp. explains it all in “Photon by Photon: The Evolution of the Geiger-Mode Silicon Avalanche Photodiode for Single-Photon Counting,” beginning on page 38.

And, finally, Chi Zhang, Konstantin Maslov and Lihong V. Wang of Washington University in St. Louis describe how in vivo, label-free subwavelength-resolution photoacoustic microscopy enables more precise measurement of optical absorption – and, therefore, provides more information. Read about it in “Photoacoustic Microscopy Unlocks Secrets of Optical Absorption,” beginning on page 24.

I hope you enjoy the issue.