Blue metal–organic framework encapsulated denatured R-phycoerythrin proteins for a white-light-emitting thin film

Abstract

Fluorescent proteins (FPs) with good photostability and outstanding photoluminescence features are very promising luminous materials for the fabrication of white-light-emitting diodes (WLEDs). However, the requirement of an aqueous environment and poor thermal stability have strongly restricted their wide applications in lighting devices. In this paper, we present a facile strategy to encapsulate R-phycoerythrin (R-PE) fluorescent proteins into a blue metal organic framework (MOF) HSB-W1 (HSB = hydrogenated Schiff base) thin film through a facile solid-confinement conversion process. As a result, R-PE proteins embedded into HSB-W1 crystals are denatured, but exhibit dual color fluorescence emissions including green (518 nm) and red (600, 647 nm) light, while the original single orange light (578 nm) is significantly suppressed. After careful adjustment of R-PE content, the resulting R-PE@HSB-W1 thin film emits high-quality white light with nearly ideal Commission Internationale de I’Eclairage (CIE) coordinates of (0.33, 0.34), a high color rendering index (CRI) value of approximately 85 and a moderately correlated color temperature (CCT) value of 5740 K. Such a strategy can be widely utilized for other fluorescent molecules and luminescent MOFs to design white-light-emitting materials.