Journal: Advanced Materials (Deerfield Beach, Fla.)

Article Title: Unlocking NIR‐II Photoluminescence in 2D Copper Tetrasilicate Nanosheets through Flame Spray Synthesis

doi: 10.1002/adma.202503159

Figure Lengend Snippet: Photoluminescence engineering of copper tetrasilicates enables emission shift to NIR‐II window. a) NIR emission spectrum of BaCuSi 4 O 10 and its mixed forms showing a significant impact of (multi)element doping toward shifting the emission into the NIR‐II window (> 1000 nm). b) Evaluation of the NIR emission spectra as integrated for NIR‐I (simplified as < 1000 nm) and for NIR‐II (> 1000 nm). c) Simplified energy diagram of Cu 2+ ion within a tetragonally distorted crystal field, for i) non‐doped, single M ‐containing NS and ii) multielement doped NS, highlighting the shifted E a energy levels iii). d) Absolute photoluminescence quantum yield (PL‐QY) spectra of CaCuSi 4 O 10 . Integrated photon counts within the gray box, excitation at 630 nm. e) PL‐QY dependency on the excitation wavelengths (red line = Gaussian fit; PL‐QY = 32%). f) PL‐QY engineering through variation of annealing temperature of resynthesized CTS. g) PL‐QY engineering through optimizing annealing time, showing a general trend of increasing PL‐QY with prolonged annealing (mean ± SD). h) Correlation between the lattice parameters a and c , obtained from Rietveld refinement, and the calculated (mean) ionic radius of the (mixed) alkaline earth metal CTS. i) Correlation of the optimized PL‐QY to the emission wavelengths of all synthesized 2D CTS variations (for comparison with reference values see Figure (Supporting Information), red line = second order polynomial fit). j) Correlation between the PL‐QY and fluorescence lifetime of all obtained materials (red line = second order polynomial fit of non‐Mg containing NS).

Article Snippet: In addition, NIR fluorescence emission spectra were recorded with a NIRQuest+1.7 spectrometer (slit width = 200 μm; InGaAs detector, OceanOptics), fiber‐coupled to a customized Axiovert 40CFL using a 10x objective, 800 nm dichroic mirror (Edmund optics) and 900 nm LP filter (FELH0900, Thorlabs).

Techniques: Synthesized, Comparison, Fluorescence

Journal: Advanced Materials (Deerfield Beach, Fla.)

Article Title: Unlocking NIR‐II Photoluminescence in 2D Copper Tetrasilicate Nanosheets through Flame Spray Synthesis

doi: 10.1002/adma.202503159

Figure Lengend Snippet: Nanosheet annealing through laser irradiation. a) Photograph of primary FSP particles (i; cyan) rearranged into NIR‐fluorescent SrCuSi 4 O 10 (ii; blue) through 808 nm laser irradiation (15.3 W cm −2 , white circle) (scale bar = 0.5 cm). b) Schematic representation of the in situ rearrangement process and XRD pattern of the corresponding particles. The amorphous primary FSP particles anneal within seconds into the characteristic P4/ncc tetragonal CTS crystal lattice, similar to a calcination process at 1000 °C (10 min). c) Fluorescence emission spectra of (multielement doped) CTS obtained by laser irradiation.

Article Snippet: In addition, NIR fluorescence emission spectra were recorded with a NIRQuest+1.7 spectrometer (slit width = 200 μm; InGaAs detector, OceanOptics), fiber‐coupled to a customized Axiovert 40CFL using a 10x objective, 800 nm dichroic mirror (Edmund optics) and 900 nm LP filter (FELH0900, Thorlabs).

Techniques: Irradiation, In Situ, Fluorescence

Journal: Advanced Materials (Deerfield Beach, Fla.)

Article Title: Unlocking NIR‐II Photoluminescence in 2D Copper Tetrasilicate Nanosheets through Flame Spray Synthesis

doi: 10.1002/adma.202503159

Figure Lengend Snippet: Engineered nanosheets for super‐resolution mapping of the murine brain. a) Schematic of the diffuse optical localization imaging (DOLI) system used for cerebrovascular imaging in the NIR window. A SWIR camera was used to collect the fluorescence emission of a dispersion of stabilized NS injected intravenously (i.v.) under 808 nm excitation (850 mW cm −2 ). b) Photostability of CTS NSs compared to a common organic dye (Rhodamine B). c) High‐frame‐rate imaging of CaCuSi 4 O 10 NS placed inside a vessel‐mimicking Teflon tube (280 µm inner diameter). Light scattering of brain tissues was mimicked with a 1.2% intralipid (IL) phantom (scale bar = 500 µm). d) Time‐lapse widefield images post DMSA‐stabilized NS injection (scale bar = 1 mm). e) Differentiation of veins and arteries based on their different perfusion patterns, distinguished through principal component analysis (PCA) (scale bar = 1 mm). f) Schematic overview i) of the working principle of DOLI rendering the structural ii), blood flow direction iii) and velocity iv, mm/s) maps of cerebral vasculature from continuous localization and tracking of circulating PEGylated NSs (scale bar = 1 mm).

Article Snippet: In addition, NIR fluorescence emission spectra were recorded with a NIRQuest+1.7 spectrometer (slit width = 200 μm; InGaAs detector, OceanOptics), fiber‐coupled to a customized Axiovert 40CFL using a 10x objective, 800 nm dichroic mirror (Edmund optics) and 900 nm LP filter (FELH0900, Thorlabs).

Techniques: Imaging, Fluorescence, Dispersion, Injection

Journal: Advanced Materials (Deerfield Beach, Fla.)

Article Title: Unlocking NIR‐II Photoluminescence in 2D Copper Tetrasilicate Nanosheets through Flame Spray Synthesis

doi: 10.1002/adma.202503159

Figure Lengend Snippet: Individual macrophage tracking in vivo. a) Macrophage cell toxicity test for various NS compared to SiO 2 (Aerosil 90; mean ± SD). b) Schematic representation of NSs uptaken by human macrophages, with respective bright field (BF) and NIR‐fluorescence images of a single NS‐labeled cell. c) Overlay of all tracked macrophages (N = 15) resemble parts of the vasculature tree (DOLI image from Figure , Supporting Information; scale bar = 1 mm).

Article Snippet: In addition, NIR fluorescence emission spectra were recorded with a NIRQuest+1.7 spectrometer (slit width = 200 μm; InGaAs detector, OceanOptics), fiber‐coupled to a customized Axiovert 40CFL using a 10x objective, 800 nm dichroic mirror (Edmund optics) and 900 nm LP filter (FELH0900, Thorlabs).

Techniques: In Vivo, Fluorescence, Labeling