Upconversion Multicolor Fine-Tuning: Visible to Near-Infrared Emission from Lanthanide-Doped NaYF₄ Nanoparticles

Upconversion Multicolor Fine-Tuning: Visible to Near-Infrared Emission from Lanthanide-Doped NaYF4 Nanoparticle

F^– Serve as Surface Trapping Sites to Promote the Charge Separation and Transfer of TiO₂

Finding an effective strategy to promote the charge transfer and separation of TiO2 is urgently needed. Herein, a surface fluorination (F–)-modified TiO2 (denoted as TO-xF, where x represents the volume of HF added in the solution) catalyst has been prepared by a mild and facile post-treatment method. The changes induced by surface F– on the morphological, structural, and surface electronic features and the charge separation and transfer efficiency of TiO2 were specifically examined. Compared with pristine TO, TO-0.4F exhibits enhanced photocatalytic degradation of methyl orange and phenol, production of hydroxyl radicals, and photocurrent response. The enhanced photocatalytic activities of TO-0.4F can be attributed to the role of surface F– as surface trapping sites in effectively boosting the charge transfer and separation processes, which is verified by the steady-state and time-resolved fluorescence spectroscopy, electrochemical impedance spectroscopy, Bode plot, transient photocurrent response, and open-circuit voltage measurements. This study emphasizes the role of surface F– in promoting the charge transfer and separation and improving the photocatalytic activity of TiO2

One-Step, Room Temperature, Colorimetric Detection of Mercury (Hg²⁺) Using DNA/Nanoparticle Conjugates

Introduction of Hg2+ into an aqueous solution containing oligonucleotide-tethered gold nanoparticle probes and a linker oligonucleotide with a number of thymine−thymine (T−T) mismatches results in the formation of particle aggregates at room temperature with a concomitant colorimetric response. The high selectivity of this detection system is attributed to Hg2+-mediated formation of T−Hg2+−T base pairs as evidenced by an increase in a sharp melting temperature

Pd Nanoparticles Supported on N‑Doped TiO₂ Nanosheets: Crystal Facets, Defective Sites, and Metal–Support Interactions Boost Reforming of Formaldehyde Solution for Hydrogen Production

To produce H2 from formaldehyde (HCHO), dehydrogenation offers an alternative approach to future hydrogen-based energy sources, but the unsatisfactory efficiency hinders its practical application. Here, ultrafine Pd nanoparticle (NP) decorated N-doped TiO2 nanosheets exposed with (001) facet catalysts (denoted as Pd/TiO2–x) have been prepared and exhibit superior H2 production performance from alkaline HCHO aqueous solution. Under our current conditions, the Pd/TiO2–x catalyst with a Pd loading of 1 wt % exhibits a H2 production rate of 183.77 mL/min/g, which is 1.75 and 3.66 times that of Pd/TiO2 and Pd NPs, respectively. Based on the results of Fourier transform infrared spectroscopy (FTIR), Raman, and liquid-phase electron paramagnetic resonance (EPR) spin-trapping experiments, the excellent H2 generation of Pd/TiO2–x can be attributed to the synergistic contribution among the reactive crystal facets, defective sites, and metal–support interactions in boosting the breakage of C–H bonds in HCHO, dissociation of H2O, and ultimately the formation of H2. This work is expected to provide a paradigm of an efficient catalyst to produce H2 from HCHO/H2O solution

One-Pot Synthesis of Amine-Substituted Aryl Sulfides and Benzo[<i>b</i>]thiophene Derivatives

A series of amine-substituted aryl sulfides have been synthesized from nitroaryl halides via a simple one-pot procedure involving metal-free C−S cross-coupling and in situ nitro group reduction. Various nitroaryl halides were reacted with thiols in recyclable poly(ethylene glycol) to afford the amine-substituted aryl sulfides in high yield. Additionally, the cross-coupling reactions of nitro- and aldehyde-substituted aryl halides with benzyl thiols under the same reaction conditions were demonstrated to afford benzothiazole and phenylbenzo[b]thiophene derivatives

Unveiling the Spatiotemporal and Dose Responses within a Single Live Cancer Cell to Photoswitchable Upconversion Nanoparticle Therapeutics Using Hybrid Hyperspectral Stimulated Raman Scattering and Transient Absorption Microscopy

Photodynamic therapy (PDT) provides an alternative approach to targeted cancer treatment, but the therapeutic mechanism of advanced nanodrugs applied to live cells and tissue is still not well understood. Herein, we employ the hybrid hyperspectral stimulated Raman scattering (SRS) and transient absorption (TA) microscopy developed for real-time in vivo visualization of the dynamic interplay between the unique photoswichable lanthanide-doped upconversion nanoparticle-conjugated rose bengal and triphenylphosphonium (LD-UCNP@CS-Rb-TPP) probe synthesized and live cancer cells. The Langmuir pharmacokinetic model associated with SRS/TA imaging is built to quantitatively track the uptakes and pharmacokinetics of LD-UCNP@CS-Rb-TPP within cancer cells. Rapid SRS/TA imaging quantifies the endocytic internalization rates of the LD-UCNP@CS-Rb-TPP probe in individual HeLa cells, and the translocation of LD-UCNP@CS-Rb-TPP from mitochondria to cell nuclei monitored during PDT can be associated with mitochondria fragmentations and the increased nuclear membrane permeability, cascading the dual organelle ablations in cancer cells. The real-time SRS spectral changes of cellular components (e.g., proteins, lipids, and DNA) observed reflect the PDT-induced oxidative damage and the dose-dependent death pattern within a single live cancer cell, thereby facilitating the real-time screening of optimal light dose and illumination duration controls in PDT. This study provides new insights into the further understanding of drug delivery and therapeutic mechanisms of photoswitchable LD-UCNP nanomedicine in live cancer cells, which are critical in the optimization of nanodrug formulations and development of precision cancer treatment in PDT

Tuning Solvatochromism of Azo Dyes with Intramolecular Hydrogen Bonding in Solution and on Titanium Dioxide Nanoparticles

“Smart tuning” of optical properties in three azo dyes containing intramolecular hydrogen bonding is realized by the judicious control of solvents, when the dyes are in solution or adsorbed onto titanium dioxide nanoparticles. In solution, certain solvents destabilizing intramolecular hydrogen bonding induce a distinctive ≈70 nm “blue-shifted” absorption peak, compared with other solvents. In parallel, the optical properties of azo dye/TiO₂ nanocomposites can be tuned using solvents with different hydrogen-bond accepting/donating abilities, giving insights into smart materials and dye-sensitized solar cell device design. It is proposed that intramolecular hydrogen bonding alone plays the leading role in such phenomena, which is fundamentally different to other mechanisms, such as tautomerism and <i>cis</i>–<i>trans</i> isomerization, that explain the optical control of azo dyes. Hybrid density functional theory (DFT) is employed in order to trace the origin of this optical control, and these calculations support the mechanism involving intramolecular hydrogen bonding. Two complementary studies are also reported: ¹H NMR spectroscopy is conducted in order to further understand the solvent effects on intramolecular hydrogen bonding; crystal structure analysis from associated research indicates the importance of intramolecular hydrogen bonding on intramolecular charge transfer

Unveiling the Spatiotemporal and Dose Responses within a Single Live Cancer Cell to Photoswitchable Upconversion Nanoparticle Therapeutics Using Hybrid Hyperspectral Stimulated Raman Scattering and Transient Absorption Microscopy

Photodynamic therapy (PDT) provides an alternative approach to targeted cancer treatment, but the therapeutic mechanism of advanced nanodrugs applied to live cells and tissue is still not well understood. Herein, we employ the hybrid hyperspectral stimulated Raman scattering (SRS) and transient absorption (TA) microscopy developed for real-time in vivo visualization of the dynamic interplay between the unique photoswichable lanthanide-doped upconversion nanoparticle-conjugated rose bengal and triphenylphosphonium (LD-UCNP@CS-Rb-TPP) probe synthesized and live cancer cells. The Langmuir pharmacokinetic model associated with SRS/TA imaging is built to quantitatively track the uptakes and pharmacokinetics of LD-UCNP@CS-Rb-TPP within cancer cells. Rapid SRS/TA imaging quantifies the endocytic internalization rates of the LD-UCNP@CS-Rb-TPP probe in individual HeLa cells, and the translocation of LD-UCNP@CS-Rb-TPP from mitochondria to cell nuclei monitored during PDT can be associated with mitochondria fragmentations and the increased nuclear membrane permeability, cascading the dual organelle ablations in cancer cells. The real-time SRS spectral changes of cellular components (e.g., proteins, lipids, and DNA) observed reflect the PDT-induced oxidative damage and the dose-dependent death pattern within a single live cancer cell, thereby facilitating the real-time screening of optimal light dose and illumination duration controls in PDT. This study provides new insights into the further understanding of drug delivery and therapeutic mechanisms of photoswitchable LD-UCNP nanomedicine in live cancer cells, which are critical in the optimization of nanodrug formulations and development of precision cancer treatment in PDT

Chemical Origami: Formation of Flexible 52-Membered Tetranuclear Metallacycles via a Molecular Square Formed from a Hemilabile Ligand

A novel tetranuclear rhodium complex has been synthesized by reaction of N,N‘-dimethyl-N,N‘-bis[2-(diphenylphosphino)ethyl]-1,4-phenylenediamine with a “Rh(I) source” generated from the reaction between [RhCl(coe)2]2 (coe = cyclooctene) and AgOTs (OTs = p-toluenesulfonate). Significantly, the complex can be reacted with small molecules that selectively break the N−Rh links to afford flexible, 52-membered tetranuclear macrocycles

Unveiling the Spatiotemporal and Dose Responses within a Single Live Cancer Cell to Photoswitchable Upconversion Nanoparticle Therapeutics Using Hybrid Hyperspectral Stimulated Raman Scattering and Transient Absorption Microscopy

Photodynamic therapy (PDT) provides an alternative approach to targeted cancer treatment, but the therapeutic mechanism of advanced nanodrugs applied to live cells and tissue is still not well understood. Herein, we employ the hybrid hyperspectral stimulated Raman scattering (SRS) and transient absorption (TA) microscopy developed for real-time in vivo visualization of the dynamic interplay between the unique photoswichable lanthanide-doped upconversion nanoparticle-conjugated rose bengal and triphenylphosphonium (LD-UCNP@CS-Rb-TPP) probe synthesized and live cancer cells. The Langmuir pharmacokinetic model associated with SRS/TA imaging is built to quantitatively track the uptakes and pharmacokinetics of LD-UCNP@CS-Rb-TPP within cancer cells. Rapid SRS/TA imaging quantifies the endocytic internalization rates of the LD-UCNP@CS-Rb-TPP probe in individual HeLa cells, and the translocation of LD-UCNP@CS-Rb-TPP from mitochondria to cell nuclei monitored during PDT can be associated with mitochondria fragmentations and the increased nuclear membrane permeability, cascading the dual organelle ablations in cancer cells. The real-time SRS spectral changes of cellular components (e.g., proteins, lipids, and DNA) observed reflect the PDT-induced oxidative damage and the dose-dependent death pattern within a single live cancer cell, thereby facilitating the real-time screening of optimal light dose and illumination duration controls in PDT. This study provides new insights into the further understanding of drug delivery and therapeutic mechanisms of photoswitchable LD-UCNP nanomedicine in live cancer cells, which are critical in the optimization of nanodrug formulations and development of precision cancer treatment in PDT