Fluorescence‐Quenching‐Based Enzyme‐Activity Assay by Using Photon Upconversion

Abstract

Switch the lights off! A novel sensitive enzyme-activity assay combines the advantageous features of upconverting phosphors (UCPs) and fluorescence quenching. The new assay principle allows the use of fluorescent particulate labels in a quenching-based assay despite the fact that it is not possible to achieve adequate quenching efficiency of particle fluorescence directly. Infrared excitation enables even the use of colorful samples. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z705861_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.