Circular Dichroism and Circular Polarized Luminescence from a Green Fluorescent Protein—Initial Research for Chiroptical Emission of Biological Materials

Abstract

Optical properties of a green fluorescent protein (GFP) are examined using optical absorption, circular dichroism (CD), and circular polarized luminescence (CPL) spectroscopies. The GFP has chiroptical activity and exhibits green circular polarized emission, although the g _em-factor is small. Poly(vinyl alcohol) (PVA)/GFP composite films are prepared to attempt long-term preservation of the GFP emission activity. After five years, the transparent PVA/GFP composite film still exhibits stable fluorescence that appears similar to the emission from the Aequorea jellyfish.

Keywords:

• circular dichroism (CD)
• circular polarized luminescence (CPL)
• green fluorescent protein (GFP)
• photoluminescence, poly(vinyl alcohol) (PVA)

The authors thank the Engineering Workshop and the Chemical Analysis Center of the University of Tsukuba for glasswork. The authors express sincere appreciation to Prof. K. Akagi for continuing encouragement and for providing the CPL instrumentation.