Classroom Demonstrations of Concepts in Molecular Fluorescence

Abstract

A multichannel CCD-array spectrophotometer and handheld UV lamp are utilized to acquire and project in real-time the fluorescence emission spectra of quinine, fluorescein, eosin yellow, and rhodamine B. Instrumental concepts of fluorescence are illustrated based on the setup of the demonstration. The emission spectra of the fluorophores are correlated with the visual color of the luminescence. The absorbance and fluorescence emission spectra of quinine in tonic water, along with the Hg source spectrum, are visually compared. This demonstration provides a framework for describing the transitions involved in fluorescence spectroscopy.