Reversible fluorescence modulation of spiropyran-functionalized carbon nanoparticles

Abstract

Fluorescent carbon nanoparticles (CNPs) with diameters of about 3 nm which can emit blue-green light were synthesized through the hydrothermal carbonization of ethylenediaminetetraacetic acid disodium salt (EDTA$2Na). Then, the CNPs were functionalized with spiropyrans to obtain the spiropyranfunctionalized CNPs. The emission of the spiropyran-functionalized CNPs centered at 510 nm could be switched off, while being turned on at 650 nm via energy transfer after UV light irradiation. The process could be reversed by using visible light irradiation. The optical switching of the fluorescence was repeated 10 times without apparent "fatigue", showing excellent photoreversibility and high stability.Spiropyran-functionalized CNPs may find potential applications in biological imaging and labeling, reversible data storage/erasing, as well as individual light-dependent nanoscale devices.

Photoregulation of α‐Chymotrypsin Activity by Spiropyran‐Based Inhibitors in Solution and Attached to an Optical Fiber

“…Subsequent excitation of this isomer with 532 nm laser (as before) resulted in an enhanced (sixfold) average fluorescence relative to the SP isomer. This is consistent with the fluorescence characteristics of the MC isomer, where this isomer is known to have enhanced fluorescence due to π‐conjugation as reported in literature13, 24, 30 (Figure 6, black, λ em ∼630 nm). Subsequent exposure of the Fiber‐2 d to visible light for 5 min decreased the fluorescence intensity, as expected for a photostationary state enriched in SP isomer.…”

Surface‐Passivated Cesium Lead Halide Perovskite Quantum Dots: Toward Efficient Light‐Emitting Diodes with an Inverted Sandwich Structure

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Metal‐Organic Frameworks as Hosts for Fluorinated Azobenzenes: A Path towards Quantitative Photoswitching with Visible Light

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