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.