Facile synthesis of fluorescent Au/Ce nanoclusters for high-sensitive bioimaging

Sandwiched composite electrolyte with excellent interfacial contact for high-performance solid-state sodium-ion batteries

Solid-state sodium-ion batteries have attracted significant attention due to their rich resources, high safety, and high energy density. However, the lower ionic conductivity and inferior interfacial contact between solid-state electrolytes (SSEs) and electrodes limit their practical applications. Herein, polyvinylideneuoride-co-hexauoropropylene (PVDF-HFP) membrane is selected and a novel sandwiched composite PVDF-HFP/Na2.5Zr1.95Ce0.05Si2.2P0.8O11.3F0.7/PVDF-HFP (G-NZC0.05SPF0.7-G) SSEs is well designed. The ionic conductivity of Na3Zr2Si2PO12 is enhanced by Ce4+/F- co-doping. The effects of Ce4+ and F- doping on the crystal structure, density, and ionic conductivity for Na3Zr2Si2PO12 are well investigated. The optimal NZC0.05SPF0.7 delivers a high ionic conductivity of 1.39 × 10-3 S cm-1 at 25 ℃. Moreover, the PVDF-HFP membrane can significantly enhance the interface compatibility between NZC0.05SPF0.7 and electrodes. The as-prepared G-NZC0.05SPF0.7-G exhibits a large ionic conductivity of 1.07 × 10-3 S cm-1 at 25 ℃, wide electrochemical stability window up to 4.5 V, high critical current density of 1.2 A cm-2, and stable Na plating/stripping over 600 h at 0.3 A cm-2. The solid-state Na0.67Mn0.47Ni0.33Ti0.2O2/G-NZC0.05SPF0.7-G/Na battery delivers a remarkable cycling stability and rate capability at 25 ℃, indicating that the as-prepared G-NZC0.05SPF0.7-G has a promising application for solid-state SIBs. This study demonstrates an effective strategy to develop advanced solid-state electrolytes for solid-state SIBs.

Carbon dots and composite materials with excellent performances in cancer-targeted bioimaging and killing: a review

Carbon dots (CDs) are nanomaterials with excellent properties, including good biocompatibility, small size, ideal photoluminescence and surface modification, and are becoming one of the most attractive nanomaterials for the imaging, detection and treatment of tumors. Based on these advantages, CDs can be combined other materials to obtain composite particles with improved, even new, performance, mainly in photothermal and photodynamic therapies. This paper reviews the research progress of CDs and their composites in targeted tumor imaging, detection, diagnosis, drug delivery and tumor killing. It also discusses and proposes the challenges and perspectives of their future applications in these fields. This review provides ideas for future applications of novel CD-based materials in the diagnosis and treatment of cancer.

Precious metal clusters as fundamental agents in bioimaging usability

Fluorescent nanomaterials (NMs) are widely used in imaging techniques in biomedical research. Especially in bioimaging systems, with the rapid development of imaging nanotechnology, precious metal clusters such as Au, Ag, and Cu NMs have emerged with different functional agents for biomedical applications. Compared with traditional fluorescent molecules, precious metal clusters have the advantages of high optical stability, easy regulation of shape and size, and multifunctionalization. In addition, NMs possess strong photoluminescent properties with good photostability, high release rate, and sub-nanometer size. They could be treated as fundamental agents in bioimaging usability. This review summarizes the recent advances in bioimaging utilization, it conveys that metal clusters refer to Au, Ag, and Cu fluorescent clusters and could provide a generalized overview of their full applications. It includes optical property measurement, precious metal clusters in bioimaging systems, and a rare earth element-doped heterogeneous structure illustrated in biomedical imaging with specific examples, that provide new and innovative ideas for fluorescent NMs in the field of bioimaging usability.

Hydrogen Peroxide and Hypochlorite Responsive Fluorescent Nanoprobes for Sensitive Cancer Cell Imaging

Accurate diagnosis of cancer cells directly affects the clinical treatment of cancer and can significantly improve the therapeutic effect of cancer patients. Cancer cells have a unique microenvironment with a large amount of peroxide inside, effectively differentiated from relevant microenvironment normal cells. Therefore, designing the high-sensitive probes to recognize and distinguish the special physiological microenvironment of cancer cells can shed light on the early diagnosis of cancers. In this article, we design and construct a fluorescence (FL) contrast agent for cancer cell recognition and imaging analysis. Firstly, luminol-gold NPs (Lum-AuNPs) have been initially built, and then successfully loaded with the fluorescent receptor Chlorin e6 (Ce6) to prepare the luminescent nanoprobes (Ce6@Lum-AuNPs) with green synthesis, i.e., with biocompatible agents and mild temperature. The as-prepared fluorescent Ce6@Lum-AuNPs can efficiently and sensitively realize FL bioimaging of cancer cells. The relevant bio-sensing mechanism pertains to the presence of hypochlorite (ClO^-); hydrogen peroxide (H₂O₂) in cancer cells could readily interact with luminol to produce chemiluminescence, which can activate the Ce6 component to emit near-infrared (NIR) FL. Therefore, this raises the possibility of utilizing the Ce6@Lum-AuNPs as efficient fluorescent nanoprobes for promising cancer early diagnosis and other relevant disease bioanalysis.

Recent progress in plant-gold nanoparticles fabrication methods and bio-applications

The preparation of gold nanoparticles via green routes applying plant extracts as the reducing agents and stabilizers has received broad interest in the last decades. Plant-gold nanoparticles have been well-developed and applied in biochemical and medical research, but there are still challenges that must be overcome. The main challenges include the construction of chemically-robust plant-gold nanoparticles, the precise design of biomimetic surfaces to fabricate nanozymes with high catalytic activities, and the development of approaches to construct biosensors with high selectivities and sensitivities. The cores and surfaces of plant-gold nanoparticles must be considered, as well as their catalytic activities and biosensing mechanisms. This review highlights the latest achievements in plant-gold nanoparticle preparation, heterogeneous nucleation, and surface functionalization, while also focusing on their optical properties and various biological and catalytic activities. Moreover, their antioxidant and cell apoptosis mechanisms, and biological activities are described. Plant-gold nanoparticles have shown great potential in high-performance analytical assays, high-activity catalysts, effective intracellular imaging, and clinical treatment.

Preparation, Cytotoxicity, and In Vitro Bioimaging of Water Soluble and Highly Fluorescent Palladium Nanoclusters

Fluorescent probes offer great potential to identify and treat surgical tumors by clinicians. To this end, several molecular probes were examined as in vitro and in vivo bioimaging probes. However, due to their ultra-low extinction coefficients as well as photobleaching problems, conventional molecular probes limit its practical utility. To address the above mentioned challenges, metal nanoclusters (MNCs) can serve as an excellent alternative with many unique features such as higher molar extinction coefficients/light absorbing capabilities, good photostability and appreciable fluorescence quantum yields. Herein, we reported a green synthesis of water soluble palladium nanoclusters (Pd NCs) and characterized them by using various spectroscopic and microscopic characterization techniques. These nanoclusters showed excellent photophysical properties with the characteristic emission peak centered at 500 nm under 420 nm photoexcitation wavelength. In vitro cytotoxicity studies in human cervical cancer cells (HeLa) cells reveal that Pd NCs exhibited good biocompatibility with an IC₅₀ value of >100 µg/mL and also showed excellent co-localization and distribution throughout the cytoplasm region with a significant fraction translocating into cell nucleus. We foresee that Pd NCs will carry huge potential to serve as a new generation bioimaging nanoprobe owing to its smaller size, minimal cytotoxicity, nucleus translocation capability and good cell labelling properties.

Genome-wide functional analysis on the molecular mechanism of specifically biosynthesized fluorescence Eu complex

Fluorescence imaging as an attractive diagnostic technique is widely employed for early diagnosis of cancer. Self-biosynthesized fluorescent Eu complex in situ in Hela cells have realized specifically and accurately fluorescence imaging for cancer cells. But the molecular mechanism of the in situ biosynthesized process is still unclear. In order to reveal this mechanism, we have investigated whole-genome expression profiles with cDNA microarray, incubated with Eu solution in Hela cells for 24 h. Methylthiazoltetrazolium (MTT) assay and laser confocal fluorescence microscopy study showed the low cytotoxicity and specifically fluorescence imaging of Eu complex in Hela cells. It is observed that 563 up-regulated genes and 274 down-regulated genes were differentially expressed. Meanwhile, quantitative RT-PCR was utilized to measure the expression of some important genes, which validated the results of microarray data analysis. Besides, GO analysis showed that a wide range of differential expression functional genes involved in three groups, including cellular component, molecular function and cellular biological process. It was evident that some important biological pathways were apparently affected through KEGG pathway analysis, including focal adhesion pathway and PI3K (phosphatidylinositol 3' -kinase)-Akt signaling pathway, which can influence glycolytic metabolism and NAD(P)H-oxidases metabolic pathway.

Stimulus responsive nanogel with innate near IR fluorescent capability for drug delivery and bioimaging

A brighter, non toxic and biocompatible optical imaging agent is one of the major quests of biomedical research. Here in, we report a photoluminescent comacromer [PEG-poly(propylene fumarate)-citric acid-glycine] and novel stimulus (pH) responsive nanogel endowed with excitation wavelength dependent fluorescence (EDF) for combined drug delivery and bioimaging applications. The comacromer when excited at different wavelengths in visible region from 400nm to 640nm exhibits fluorescent emissions from 510nm to 718nm in aqueous condition. It has high Stokes shift (120nm), fluorescent lifetime (7 nanoseconds) and quantum yield (50%). The nanogel, C-PLM-NG, prepared with this photoluminescent comacromer and N,N-dimethyl amino ethylmethacrylate (DMEMA) has spherical morphology with particle size around 100nm and 180nm at pH 7.4 (physiological) and 5.5 (intracellular acidic condition of cancer cells) respectively. The studies on fluorescence characteristics of C-PLM NG in aqueous condition reveal large red-shift with emissions from 523nm to 700nm for excitations from 460nm to 600nm ascertaining the EDF characteristics. Imaging the near IR emission with excitation at 535nm was accomplished using cut-off filters. The nanogel undergoes pH responsive swelling and releases around 50% doxorubicin (DOX) at pH 5.5 in comparison with 15% observed at pH 7.4. The studies on in vitro cytotoxicity with MTT assay and hemolysis revealed that the present nanogel is non-toxic. The DOX-loaded C-PLM-NG encapsulated in Hela cells induces lysis of cancer cells. The inherent EDF characteristics associated with C-PLM NG enable cellular imaging of Hela cells. The studies on biodistribution and clearance mechanism of C-PLM-NG from the body of mice reveal bioimaging capability and safety of the present nanogel. This is the first report on a polymeric nanogel with innate near IR emissions for bioimaging applications.

Rapid and accurate tumor-target bio-imaging through specific in vivo biosynthesis of a fluorescent europium complex

We explored a novel strategy for the in situ self-imaging of cancer cells and tumors using a specifically biosynthesized fluorescent Eu complex.

Biomedical applications of nano-titania in theranostics and photodynamic therapy

Titanium dioxide (TiO₂) is one of the most abundantly used nanomaterials for human life. It is used in sunscreen, photovoltaic devices, biomedical applications and as a food additive and environmental scavenger.

Adenosine monophosphate-capped gold(i) nanoclusters: synthesis and lanthanide ion-induced enhancement of their luminescence

Reduction of Au³⁺ in the presence of just AMP and HEPES, combined with light exposure, gives rise to luminescent, water-soluble Au⁺ nanoclusters. Their photoluminescence is considerably enhanced by adding Y³⁺ or Yb³⁺, which leads to Au⁺/Y³⁺ and Au⁺/Yb³⁺ NCs, respectively.

One-pot development of water soluble copper nanoclusters with red emission and aggregation induced fluorescence enhancement

The binding of Zn²⁺ and Al³⁺ to OH on the copper core of Cu NCs promotes the formation of Cu NC–OH–Zn–OH–Cu NCs and Cu NC–OH–Al–OH–Cu NCs aggregates, which enables aggregation induced fluorescence enhancement.

Green synthesis of highly fluorescent AuNCs with red emission and their special sensing behavior for Al3+

Facile methods were fabricated for preparation of highly fluorescent AuNCs with red emission using l-cysteine.