Electrochemical immunosensing by carbon ink/carbon dot/ZnO-labeled-Ag@polypyrrole composite biomarker for CA-125 ovarian cancer detection.

In this work, we demonstrated a novel cancer antigen 125 (CA125) biomarker detection based on electrochemical immunosensor. The biomarker on conductive composite materials of carbon ink/carbon dot/zine oxide (C-ink/CD/ZnO) was employed as an electrode platform by using ITO substrate to enhance the interaction of antibodies (Ab) with supporting catalytic performance of ZnO as a labeling signal molecule. They were a scientist attention for biosensor with chemical stability, strong biocompatibility, high conductive signal, and accuracy. Moreover, the nanocomposite of silver@polypyrrole (Ag@PPy) was used as a potential redox mediator. The labeled construction with Ag@PPy was more accuracy than that of a free-labeled. The created immunosensor was a wide linear range as 1 ag·mL-1 - 100 ng·mL-1 and a low limitation of detection as 0.1 fg·mL-1 under the optimal condition. This suggested that the immunosensor is considered to be an accurate and efficient diagnostic tool for CA125 and other biomarkers detection in actual sample analysis for clinic.

Hierarchical Composite Nanoarchitectonics with a Graphitic Core, Dendrimer and Fluorocarbon Domains, and a Poly(ethylene glycol) Shell as O2 Reservoirs for Reactive Oxygen Species Production.

Graphene oxide (GO), single-walled carbon nanohorn (CNHox), and nitrogen-doped CNH (N-CNH) were functionalized with fluorinated poly(ethylene glycol) (F-PEG) and/or with a fluorinated dendrimer (F-DEN) to prepare a series of assembled nanocomposites (GO/F-PEG, CNHox/F-PEG, N-CNH/F-PEG, N-CNH/F-DEN, and N-CNH/F-DEN/F-PEG) that provide effective multisite O2 reservoirs. In all cases, the O2 uptake increased with time and saturated after 10-20 min. When graphitic carbons (GO and CNHox) were coated with F-PEG, the O2 uptake doubled. The O2 loading was slightly higher in N-CNH compared to CNHox. Notably, coating N-CNH with F-DEN or F-PEG, or with both F-DEN and F-PEG, was more effective. The best performance was obtained with the N-CNH/F-DEN/F-PEG nanocomposite. The O2 uptake kinetics and mechanisms were analyzed in terms of the Langmuir adsorption equation based on a multibinding site assumption. This allowed the precise determination of multiple oxygen binding sites, including on the graphitic structure and in the dendrimer, F-DEN, and F-PEG. After an initial rapid, relatively limited release, the amount of O2 trapped in the nanomaterials remained high (>95%). This amount was marginally lower for the functionalized composites, but the oxygen stored was reserved for longer times. Finally, it is shown that these systems can generate singlet oxygen after irradiation by a light-emitting diode, and this production correlates with the amount of O2 loaded. Thus, it was anticipated that the present nanocomposites hierarchically assembled from components with different characters and complementary affinities for oxygen can be useful as O2 reservoirs for singlet oxygen generation to kill bacteria and viruses and to perform photodynamic therapy.

Self-standing films of octadecylaminated-TEMPO-oxidized cellulose nanofibrils with antifingerprint properties.

Self-standing films of cellulose nanofibril derivatives were prepared via oxidation by the 2,2,6,6-tetramethyl-1-piperidinyloxy radical and amidation with octadecylamine (ODA). The transparency and rigidity of the films decreased and their flexibility increased as the amide/carboxyl ratio increased. The introduction of the ODA also resulted in rising contact angles of water (from 43.5° to 117°) and oleic acid (from 22.5° to 57.1°). Furthermore, the films exhibited unique oil repellency: a drop of hexadecane slipped without tailing on the surface modified by ODA. This phenomenon was observed after moderate modification (water contact angle: 95-114°) and was absent for the films with the lowest and highest extents of modification. Then, the antifingerprint property of the films was examined by means of the powder test, and a reduction in fingerprints on the films was demonstrated. These results suggest the usefulness of developing transparent, self-standing oil-repellent films without perfluorinated compounds for antifingerprint and other antifouling applications.

Nitric Oxide Gas in Carbon Nanohorn/Fluorinated Dendrimer/Fluorinated Poly(ethylene glycol)-Based Hierarchical Nanocomposites as Therapeutic Nanocarriers.

Nitric oxide (NO) gas nanocarrier materials were prepared via a hierarchical assembly of poly(amido amine) dendrimers with fluorocarbon binding sites (DEN-F) and fluorinated poly(ethylene glycol) (F-PEG) on nitrogen-doped carbon nanohorns (NCNHs). The loading abilities of NO gas in these nanocarrier materials increased with the nitrogen doping of CNH and hierarchies formed by DEN-F and F-PEG. Especially, the ability of CNH-based nanocomposite materials was better than that of graphene-based materials. The loading of NO gas arose an infrared absorption band at 1387 cm-1 and increased the intensity ratio of D and G bands in Raman spectra, although these phenomena diminished after the degas treatment. The antimicrobial effects on bacteria (Escherichia coli and Staphylococcus aureus) increased depending on the loading amount of NO gas. It was confirmed from these results that NO gas weakly interacts with nitrogen-doped CNH and is trapped in the void volumes of DEN-F and F-PEG hierarchies. Thus, the concentric hierarchy is preferable for slow release of NO gas due to the void volumes in DEN-F, F-PEG, and CNH hierarchical organization. This sustained release of NO gas is advantageous with regards to the potential biomedical gas therapy against bacteria and other parasites.