New Templated Ostwald Ripening Process of Mesostructured FeOOH for Third‐Harmonic Generation Bioimaging

Abstract

Emerging advances in iron oxide nanoparticles exploit their high magnetization for various applications, such as bioseparation, hyperthermia, and magnetic resonance imaging. In contrast to their excellent magnetic performance, the harmonic generation and luminescence properties of iron oxide nanoparticles have not been thoroughly explored, thus limiting their development as a tool in photomedicine. In this work, a seed/growth‐inspired synthesis is developed combined with primary mineralization and a ligand‐assisted secondary growth strategy to prepare mesostructured α‐FeOOH nanorods (NRs). The sub‐wavelength heterogeneity of the refractive index leads to enhanced third‐harmonic generation (THG) signals under near‐infrared excited wavelengths at 1230 nm. The as‐prepared NRs exhibit an 11‐fold stronger THG intensity compared to bare α‐FeOOH NRs. Using these unique nonlinear optical properties, it is demonstrated that mesostructured α‐FeOOH NRs can serve as biocompatible and nonbleaching contrast agents in THG microscopy for long‐term labeling of cells as well as in angiography in vivo by modifying lectin to enhance the binding efficiency to the glycocalyx layers on the wall of blood vessels. These results provide a new insight into Fe‐based nanoplatforms capable of emitting coherent light as molecular probes in optical microscopy, thus establishing a complementary microscopic imaging method for macroscopic magnetic imaging systems.

Controlled synthesis of iron oxyhydroxide (FeOOH) nanoparticles using secretory compounds from Chlorella vulgaris microalgae

“…Besides biochemical species, chemical polymers can also control the fabrication of FeOOH nanoparticles and are employed for the shape-and size-controlled synthesis reactions [32]. It is obvious that reaction protocol and reaction conditions are other parameters that can control the resulted particle size and morphology [33,34]. FTIR spectra of uncontrolled and controlled synthesized particles were recorded and depicted in Figure 3.…”

Lamellar and Conductive Ion Associations Advance the Electrochemical Catalytic Performance of Palladium

“…In Scheme 1, a possible formation mechanism of Pd/ PdMoCTAB is proposed as follows: By adding CTAB into Na 2 PdCl 4 , [PdCl 4 ] 2− transforms into [PdBr 4 ] 2− , 34 and then CTA + interacts with Mo 7 O 24 6− and [PdBr 4 ] 2− via electrostatic attraction to form an ion association, which further selfassembles into a branch structure through anisotropic growth and Ostwald ripening. 34,47 The ion association with a branch structure presents the homogeneous state and has a Tyndall effect. After AA was added, atomic Pd species were generated within the lamellar structure of ion association.…”

“Nano effects”: a review on nanoparticle-induced multifarious systemic effects on cancer theranostic applications

“…Historically, this was thought to be a barrier to synthesizing and maintaining uniformly sized particles in solutions. However, OR is now thought to be an effective method for self-controlled synthesis of nanostructures via seed elongation or grain growth [41][42][43][44][45] . Ostwald Ripening is a key player in the creation of optically superior nanoparticles for use in sensors, circularly polarized luminescence sources, and other applications.…”