Fluorescein dye intercalated layered double hydroxides for chemically stabilized photoluminescent indicators on inorganic surfaces

Abstract

A new photoactive thin film of layered double hydroxide (LDH) nanocrystals containing fluorescein dyes (LDH-F) has been developed by self-assembly of the LDH nanocrystals and well-controlled intercalation of the dyes in organic media. XRD results and absorption spectra confirmed the highly oriented interlayer arrangement of the dianionic form of the fluorescein dyes in the LDH interlayers, in which the dye molecules were electrostatically immobilized between the positively charged LDH layers with a monolayer packing structure. An intensity weighted average PL lifetime was estimated to be 1.45 ns and fluorescence lifetime imaging microscopy revealed that the individual LDH nanocrystals on the LDH-F film had largely similar lifetimes, which were ascribed to the uniform loading of fluorescein dyes onto the LDH matrix without photoluminescence quenching.

Chelator-Free Labeling of Layered Double Hydroxide Nanoparticles for in Vivo PET Imaging

“…Due to its unique structure and properties, such as rich surface functionality, excellent biocompatibility, wide availability and controllable ion-exchange, LDH exhibits great potential as a delivery agent for biomedical applications 3 . In regard to diagnostic imaging applications, numerous fluorescent dyes and inorganic nanoparticles have been tethered onto LDH for optical imaging, x-ray computed tomography (CT) and magnetic resonance imaging (MRI) 4 5 6 7 8 9 10 . However, positron emission tomography (PET), which offers great sensitivity, superb tissue penetration, accurate quantification capability and excellent translational potential 11 12 13 , has not been explored with LDH-based nanoparticles.…”

Nanocomposites Based on Thermoplastic Polymers and Functional Nanofiller for Sensor Applications

“…With both the methods the dyes can be successfully intercalated as evidenced in the case of colorants to produce colour and multicolor organic-inorganic hybrid pigments [55,56,57,58,59,60], azo-dyes [61], fluorescein [62,63,64], pyrene and perylene derivatives [65,66], stilbene and anthracene derivatives [67,68,69]. However, as already mentioned, the optimization of the optical properties requires dyes molecular dispersion within the galleries.…”

“…More recently a new method of preparation of photoactive LDH-FLU thin films based on the self-assembly of the LDH nanocrystals and on well-controlled intercalation of the dye has been proposed [62]. First an oriented film made of LDH in carbonate form (LDH-C) was deposited on a Si substrate by ultrasonic treatment of the substrate in 1-butanol containing the LDH-C powder.…”

Kinetics of intercalation of fluorescent probes in magnesium–aluminium layered double hydroxide within a multiscale reaction–diffusion framework

“…Furthermore, upon formation of the MgAlA LDHs, the fluorescent probes are incorporated between the layers, causing a local increase in their concentration [36]. Accordingly, the average distance between either the RhB or the HPTS probes decreases and the fluorescence signal is quenched via homo-RET.…”