The Photodynamic Effect of Different Size ZnO Nanoparticles on Cancer Cell Proliferation In Vitro

Nanomaterials have widely been used in the field of biological and biomedicine, such as tissue imaging, diagnosis and cancer therapy. In this study, we explored the cytotoxicity and photodynamic effect of different-sized ZnO nanoparticles to target cells. Our observations demonstrated that ZnO nanoparticles exerted dose-dependent and time-dependent cytotoxicity for cancer cells like hepatocellular carcinoma SMMC-7721 cells in vitro. Meanwhile, it was observed that UV irradiation could enhance the suppression ability of ZnO nanoparticles on cancer cells proliferation, and these effects were in the size-dependent manner. Furthermore, when ZnO nanoparticles combined with daunorubicin, the related cytotoxicity of anticancer agents on cancer cells was evidently enhanced, suggesting that ZnO nanoparticles could play an important role in drug delivery. This may offer the possibility of the great potential and promising applications of the ZnO nanoparticles in clinical and biomedical areas like photodynamic cancer therapy and others

The Effect of rGO-Doping on the Performance of SnO₂/rGO Flexible Humidity Sensor

The development of a flexible and high-performance humidity sensor is essential to expand its new applications, such as personal health monitoring and early diagnosis. In this work, SnO2/rGO nanocomposites were prepared by one-step hydrothermal method. The effect of rGO-doping on humidity sensing performance was investigated. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectroscopy were used to characterize the nanostructure, morphology and chemical composition of SnO2/rGO nanocomposites. The SnO2/rGO humidity sensitive film was prepared by electrospinning on a polyimide film modified with gold electrodes. The humidity test results show that different doping ratios of rGO have different effects on humidity sensing properties. Among them, the sensor with 2 wt% rGO-doping has a high sensitivity (37,491.2%) within the humidity range as well as the fast response time (80 s) and recover time (4 s). Furthermore, the sensor with 2 wt% rGO-doping remains good flexibility and stability in the case of bending (1000 times). The sensitivity of the 2 wt% rGO-doping sensor at the bending radius (8 mm and 4 mm) is 48,219% and 91,898%, respectively. More importantly, the sensor could reflect different breathing states clearly and track breathing intervals as short as 3 s. The SnO2/rGO flexible humidity sensor with accuracy, flexibility and instantaneity as well as the facile fabrication strategy is conceivable to be applied in the potential application for human health real-time monitoring

General Strategy toward Laser Single-Step Generation of Multiscale Anti-Reflection Structures by Marangoni Effect

The anti-reflection of transparent material surfaces has attracted great attention due to its potential applications. In this paper, a single-step controllable method based on an infrared femtosecond laser is proposed for self-generation multiscale anti-reflection structures on glass. The multiscale composite structure with ridge structures and laser-induced nano-textures is generated by the Marangoni effect. By optimizing the laser parameters, multiscale structure with broadband anti-reflection enhancement is achieved. Meanwhile, the sample exhibits good anti-glare performance under strong light. The results show that the average reflectance of the laser-textured glass in the 300–800 nm band is reduced by 45.5% compared with the unprocessed glass. This work provides a simple and general strategy for fabricating anti-reflection structures and expands the potential applications of laser-textured glass in various optical components, display devices, and anti-glare glasses

Recirculating configuration all-optical wavelength conversion by self-phase modulation in a highly nonlinear photonic crystal fiber - art no 678155

Conference Name:Conference on Passive Components and Fiber-Based Devices IV. Conference Address: Wuhan, PEOPLES R CHINA. Time:NOV 02-05, 2007.A novel architecture of all-optical wavelength conversion in a highly nonlinear bismuth oxide-based photonic crystal fiber (PCF) is demonstrated. Self-phase modulation is utilized to induce spectral broadening for the all-optical wavelength converter. A recirculating configuration is designed to obtain the twice spectral broadening. Therefore, wavelength conversion is achieved. The design and the simulation of PCF are demonstrated. The desired dispersion properties can be tailored by the parameters of bismuth oxide (Bi2O3) PCF microstructure. The propagation loss at 1550nm is about 0.8dB/m. The simulation results of PCF indicate the relationship of the effective index of the fundamental mode, the mode effective area and the holes pitch of PCF. The nonlinear coefficient is expected to be 1100W(-1)km(-1) by using bismuth oxide-based glass and reducing the effective core area. The mode-field diameter of PCF is estimated to be 1.98 mu m and the predicted small effective core area is 3.3 mu m(2). The design of Bi2O3-based PCF and the intermediate high numerical aperture fibers between Bi2O3-based PCF and single-mode fibers are considered to reduce the splicing loss. The obtained results show that the wavelength converter has a potential of wide conversion bandwidth, high response time, simple configuration and low insertion loss etc

Double-conversion optical frequency shifter using multiple quasi-phase-matched LiNbO3 waveguides - art no 67833U

Conference Name:Conference on Optical Transmission, Switching and Subsystems V. Conference Address: Wuhan, PEOPLES R CHINA. Time:NOV 02-05, 2007.In this paper, we proposed a variable operation of a DC-OFS based on double SFG+DFG (Double-SFG+DFG-OFS) nonlinearity process for the first time. We studied the principle and configuration of three DC-OFS in detail both theoretically and experimentally. In order to compare with Double-DFG-OFS and Double-SHG+DFG-OFS, we also used two four-channel-controlling multiple-quasi-phase-matched LiNbO3 wavelength converters and got ten different outputs spreading across a wavelength range of as broad as 35 nm by changing the combination of two controlling wavelengths of the two wavelength converters. And one channel signal was converted to shorter and longer wavelength and the same wavelength by changing the controlling wavelengths. We got higher conversion efficiency compared with the other two DC-OFSs mentioned above. We used novel M-QPM-LN wavelength converters having a continuously-phase-modulated domain structure, which can be operated by multiple pump wavelengths with minimum loss of efficiency. The periods were 14.8 mu m. The phase of the periodic poling was continuously modulated to satisfy the QPM condition at four different wavelengths. The frequency spacing of control signal-b is twice as large as the control signal-a. The operating temperatures were 102.5 and 100.5 C for the first and the second QPM-LN wavelength converters, respectively

Cascaded wavelength conversion based on cross-gain modulation and cross-phase modulation in SOAs - art no 67833D

Conference Name:Conference on Optical Transmission, Switching and Subsystems V. Conference Address: Wuhan, PEOPLES R CHINA. Time:NOV 02-05, 2007.All-optical wavelength converters (AOWCs) that utilize nonlinearities in semiconductor optical amplifiers (SOAs) have attracted considerable research interest. AOWCs based on cross gain modulation (XGM) have a large dynamic range of the input optical signal power but a low extinction ratio (ER) and a high chirp, whereas AOWCs based on cross phase modulation (XPM) provide a low chirp and a high ER but suffer from a relative small input power dynamic range. We point out that there seems to be some complementarity between XGM and XPM. Based on this, we propose a novel scheme for cascaded wavelength conversion based on cross gain modulation and cross phase modulation in SOAs thus is expected to have a high ER and a large input power dynamic range simultaneously. The wavelength conversion operation includes two stages, that is, XGM in the first stage followed by the stage of XPM. In the XGM stage, we use a band pass filter to increase the frequency response of the SOA. In the XPM, we use the bidirectional input scheme for MZI to improve the response of XPM and cancel XGM-induced intensity unbalance to get a relative perfect interference

Variable wavelength conversion based on fan-out grating in QPM-LN - art no 67820F

Conference Name:Conference on Optoelectronic Materials and Devices II. Conference Address: Wuhan, PEOPLES R CHINA. Time:NOV 02-05, 2007.In this paper, we demonstrated for the first time variable 1.5 mu m wavelength conversion through cascaded second order nonlinear processes "SHG+DFG" by fan-out grating in lithium niobate waveguide. We fabricated the waveguide by annealed proton exchange in periodically poled LiNbO3 (PPLN). The device used in this experiment is 4 cm long, has a QPM period from 14.8 mu m to 15.2 mu m, waveguide width of 12 mu m, proton exchange depth of 0.7 mu m, and was annealed for 32h at 350 degrees C. After proton exchange in pure benzoic acid using a SiO2 mask, the substrate was annealed in an oxygen atmosphere. The wavelength of signal light was set at 1551.3 nm. The wavelengths of tunable pump lights we used in experiment were 1543.2 and 1556.2 nm, and the corresponding grating periods were 14.87 mu m and 15.03 mu m, respectively. The temperature was set at 100.5 degrees C to avoid photo refractive damage and to match the QPM peaks to the pump wavelengths. The conversion efficiency was about 10dB to be expected with the pump power 175mW in a similar device with a slightly different QPM period and operated at 125 degrees C