Single-walled carbon nanotube (SWCNT) enantiomers are useful for mechanism research and application exploration in optoelectronic components, integrated circuits, biophotonics, and other applications due to their tunable and uniformly responsive photoelectric properties. Herein, surface-enhanced Raman optical activity (ROA) was utilized to identify the structure and behavior of SWCNT enantiomers with a sensitivity of two to four SWCNTs/μm2 driven by the achiral plasmon nanostructure. The achiral plasmon nanostructure with C6 symmetry was adopted to convert far-field chiral light to significantly enhanced near-field light. The resultant Raman scattering intensities of SWCNT enantiomers with chiral indices of (7, 6) and (13, −6) have been increased ∼40 times by the achiral plasmon nanostructure compared with the SWCNT enantiomers dispersed on the silicon wafer by the same method. Thus, the difference of chiral near-field enhanced Raman scattering intensities of SWCNT enantiomers can break the limitation of the background noise to obtain the ROA spectra with vibrational-level information on target analytes. Our strategy provides a convenient and effective platform for identifying SWCNT enantiomers, as well as with extension function for ROA examination of molecular enantiomers.
A smart drug delivery system with cancer cell targeting and bioresponsive controlled drug release has been constructed by taking advantage of a protein-capped mesoporous nanovalve and a DNA aptamer.
A highly selective, fluorescence resonance energy transfer (FRET) based aptasensor for enrofloxacin (ENR) detection was developed using core–shell upconversion nanoparticles as an energy donor and graphene oxide as an energy acceptor.
For cancer therapy, optimization of carrier features is necessary to effectively deliver the targeting agents to tumor sites. Biodegradable poly(ether-anhydrides) micelles with filamentous, rod-like, and spherical shapes are fabricated. Their size and morphology are characterized by AFM and TEM. The encapsulation of doxorubicin hydrochloride (DOX) into the micelles does not impact their shape. The effect of micellar shape on the drug loading capacity and encapsulation efficiency, as well as in vitro drug release, is investigated. The cellular uptakes are evaluated using fluorescence microscopy, confocal laser scanning microscopy and flow cytometry on co-cultures of human hepatoblastoma cell line (HepG2), lung epithelial cancer cell line (A549), and human nasopharyngeal epidermoid carcinoma cells (KB) and fibroblast normal cells mixed with the different shapes of DOX-loaded micelles. The results show that the spherical DOX-loaded micelles are more readily taken up by all types of cells. The impact of micellar shape on in vivo antitumor function is also assessed from changes of tumor volume, body weight loss, and survival rate of 4T1-bearing mice and the immunostaining of tumor sections for analysis of tumor cell proliferation. The results reveal that the filamentous DOX-loaded micelles possess the highest safety to body and the best therapeutic effects to artificial solid tumors. Therefore, the filamentous shape is deemed the most suitable morphology for design and engineering of drug vehicles for cancer therapy.
Pathogenic biofilms are up to 1000-fold more drug-resistant than planktonic pathogens and cause about 80% of all chronic infections worldwide. The lack of prompt and reliable biofilm identification methods seriously prohibits the diagnosis and treatment of biofilm infections. Here, we developed a machine-learning-aided cocktail assay for prompt and reliable biofilm detection. Lanthanide nanoparticles with different emissions, surface charges, and hydrophilicity are formulated into the cocktail kits. The lanthanide nanoparticles in the cocktail kits can offer competitive interactions with the biofilm and further maximize the charge and hydrophilicity differences between biofilms. The physicochemical heterogeneities of biofilms were transformed into luminescence intensity at different wavelengths by the cocktail kits. The luminescence signals were used as learning data to train the random forest algorithm, and the algorithm could identify the unknown biofilms within minutes after training. Electrostatic attractions and hydrophobic–hydrophobic interactions were demonstrated to dominate the binding of the cocktail kits to the biofilms. By rationally designing the charge and hydrophilicity of the cocktail kit, unknown biofilms of pathogenic clinical isolates were identified with an overall accuracy of over 80% based on the random forest algorithm. Moreover, the antibiotic-loaded cocktail nanoprobes efficiently eradicated biofilms since the nanoprobes could penetrate deep into the biofilms. This work can serve as a reliable technique for the diagnosis of biofilm infections and it can also provide instructions for the design of multiplex assays for detecting biochemical compounds beyond biofilms.
We propose new types of hybrid plasmonic waveguides for low-threshold nanolaser applications.Modal properties and lasing threshold under different geometric shapes and parameters are investigated and analyzed by the finite element method, aiming to realize both low propagation and high field confinement.Results show that a smaller gap width and a larger round corner radius of the metal film reduce the lasing threshold.These new structures can open up new avenues in the fields of active plasmonic circuits.
Protective shell: A microwave-assisted method allows rapid production of biofunctional and fluorescent silicon nanoparticles (SiNPs), which can be used for cell labeling (see picture). Such SiNPs feature excellent aqueous dispersibility, are strongly fluorescent, storable, photostable, stable at different pH values, and biocompatible. The method opens new avenues for designing multifunctional SiNPs and related silicon nanostructures. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
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