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The development of an efficient tumor-specific therapeutic approach, which functions against the primary tumor and also repairs the host immune system to eradicate distant tumors, remains a clinical issue. Herein, this study focuses on the use of polydopamine-coated gold nanoparticles (Au@PDA NPs) that showed excellent selectivity towards cancer cells. The Au@PDA NPs were prepared by a plasma synthesis method with a short reaction time and minimize the use of chemicals. Prominently, Au@PDA NPs not only exhibited high cellular internalization but also stimulated immunogenic cell death (ICD) in aggressive breast carcinoma cells. Moreover, it was observed that damage-associated molecular patterns (DAMPs) were released by damaged cells together with the autophagy process after Au@PDA NPs exposure, which acted as endogenous danger signals to regulate the consequent immune response. This study highlights the novel mechanism of Au@PDA NPs-triggered anti-tumor immunity against immunosuppressive cancers, demonstrated the potential of the Au@PDA NPs for cancer immunotherapy.

The structural and optical properties of InAsxP1-x metamorphic buffers grown by metal–organic chemical vapor deposition on InP (100) substrates have been investigated. High-resolution X-ray reciprocal space mapping around the (115) InP lattice point reveals that the strain relaxations of the InAsxP1-x with x = 0.5, 0.55, and 0.7 are 98%, 92%, and 96%, while the lateral correlation lengths are 17, 62, and 28 nm, respectively. The optical bandgap energy of the InAsP derived from photoreflectance (PR) measurements decreases from 0.819 to 0.621 eV at 300 K when increasing As composition from x = 0.5 to 0.7. The bowing parameter for the optical bandgap of the InAsP is increased with increasing As composition, which is attributable to the increased spontaneous CuPt-type ordering in InAsP. It is found from the excitation power-dependent PR measurement that the InAsxP1-x layers have different degrees of the bandgap redshift due to the reduced thermal conductivity caused by crystal imperfections generated during the strain relaxation process.

We grew and characterized Zn- and Si-doped In0.48Ga0.52P grown on (0 0 1) GaAs substrates misoriented by θS = 0°, 2°, 6°, and 10° toward (1 1 1)A using metal-organic chemical vapor deposition. The dopant incorporation efficiency is improved with higher θS because of a larger surface free energy. The lattice constant of InGaP is increased with higher doping concentration, whereas it is decreased with higher θS as a result of reduced CuPt-type ordering in InGaP. This reduced ordering with θS from 0° to 10° is supported by a bandgap increase of ~60 meV. The open-circuit voltage of InGaP solar cell with θS = 10° is more than 100 meV higher than that with θS = 2° due to the increased bandgap and the decrease of the ordering-related defects. Besides, a larger CuPt-type ordering results in a greater reduction of the thermal activation energy of InGaP solar cell.

Despite possessing versatile properties and great potential for biomedical research, the number of studies on the application of polydopamine-functionalized gold nanoparticles (Au@PDA NPs) remains infrequent due to their preparation procedure, which consists of multiple-steps employing hazardous redox agents. We herein present an unprecedented single-step synthesis protocol using a non-equilibrium atmospheric pressure plasma jet to trigger the redox reaction between dopamine (DA) and gold ions in distilled water to simplify the fabrication process, eliminating the use of additional chemicals. Under the plasma treatment, the solvated electrons and reactive oxygen species generated from the plasma-liquid interaction can simultaneously reduce Au ions to metallic Au and oxidize DA to polydopamine (PDA), respectively, thus leading to the formation of Au@PDA NPs. The simultaneous reactions between plasma, DA and ionic Au create a synergistic effect shortening the reaction time compared to conventional chemical synthesis. The morphology of Au@PDA NPs can be tailored by plasma reaction time and DA concentrations. Owing to the unique properties of the quickly fabricated Au NPs, these NPs were used for the in vitro treatment of cancer cells. Interestingly, the plasma-synthesized Au@PDA NPs demonstrate high cellular uptake and cytotoxicity in breast cancer cells. Our data emphasize the importance of plasma-liquid interaction in synthesizing Au@PDA NPs for suppressing cancer cell growth and level of their intracellular delivery to improve cancer therapy. Hence, the Au@PDA NPs prepared by the one-pot plasma-assisted synthesis may have future biomedical applications as an anticancer agent.

p-type Cu2O (p-Cu2O) is a promising candidate for engineering of photocathodes for solar H2 generation but it suffers from the photo-induced corrosion process. In this work, we report on the two new strategies to overcome the photo-induced corrosion and to enhance the photocatalytic activity of the p-Cu2O photocathode: (i) a 60-to-300-nm-thick Au layer prepared by sputtering was used as a protective layer to the p-Cu2O electrode; (ii) a thin layer of n-type Cu2O was deposited onto the p-Cu2O electrode surface before sputtering the Au protective layer. For the latter, as a direct result, a pn-Cu2O homojunction was formed that was then protected by the Au thin layer. The pn-Cu2O homojunction helps to enhance the charge separation within the Cu2O electrode, consequently contributes to the enhancement of the photocatalytic activity. Under the standard 1 Sun irradiation, the best Au-protected pn-Cu2O photocathode showed an onset photovoltage of +0.55 V vs. Reversible Hydrogen Electrode (RHE), and a photocurrent density of 0.76 mA/cm2 at an applied potential of 0 V vs. RHE that remained more than 50% after 3 min of operation. Whereas, the bare p-Cu2O showed a photocurrent density of 0.3 mA/cm2 that was completely degraded after 1 min of operation under the identical conditions.

The photocatalytic activity of brookite was studied and compared with anatase, rutile, and commercial titania P25 (Degussa). Brookite exhibited relatively high activity in the degradation of different hazardous compounds under sunlight equivalent conditions. Brookite and other titania polymorphs anatase and rutile were hydrothermally synthesized under the similar reaction conditions starting with the same amorphous titania precursor. The highly crystalline titania polymorphs were characterized by XRD, SEM, TG-DSC, Raman- and diffuse reflectance UV–vis spectroscopy. Brookite (B) and anatase (A) crystallized in form of agglomerated spherical-shaped nanoparticles of ca. 10 nm in size. Rutile (R) formed up to 500 nm large rod-like nanocrystals. The band gaps of the titania polymorphs were about 3.25–3.34 eV. The aromatic ring opening in different hazardous compounds was monitored by UV–vis absorption spectroscopy and the mineralization was determined by total organic carbon (TOC) measurements. Additionally, the formation of intermediates was studied by electrospray ionization time-of-flight mass spectra (ESI-TOF-MS). The recalcitrance of organic compounds against the photocatalytic degradation increases in the following order: cinnamic acid R.