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Full-Text Articles in Physics
Influence Of Electrostatic Forces On The Particle Propulsion In The Evanescent Field Of Silver Ion-Exchanged Waveguides, Dmytro Gebennikov, Silvia Mittler
Influence Of Electrostatic Forces On The Particle Propulsion In The Evanescent Field Of Silver Ion-Exchanged Waveguides, Dmytro Gebennikov, Silvia Mittler
Physics and Astronomy Publications
The effect of electrostatic interaction between carboxylate- and amino-functionalized polystyrene particles and a charged waveguide surface on the propulsion speed in an optical tweezers is considered as a function of pH and ionic strength. It was shown that with the variation of the pH of the aqueous solution, the particles were immersed in, a systematic change of propulsion speed with a maximum speed could be achieved. The appearance of a maximum speed was ascribed to changes in the particle-waveguide separation as a result of the combination of two forces: Coulomb repulsion/attraction and induced dipole forces. The highest maximum speed at …
Optimization Of Gold Nanoring Arrays For Biosensing In The Fiber-Optic Communication Window, Hao Jiang, Tingjie Li, Jun Yang, Silvia Mittler, Jayshri Sabarinathan
Optimization Of Gold Nanoring Arrays For Biosensing In The Fiber-Optic Communication Window, Hao Jiang, Tingjie Li, Jun Yang, Silvia Mittler, Jayshri Sabarinathan
Physics and Astronomy Publications
To improve the limit of detection in a nanoplasmonic sensor system, the optical performance of the metal nanostructures should be optimized according to the best spectral window of the measurement instrument. We propose that the spectral window from 1460 to 1610 nm can potentially provide ultrahigh instrumental resolution for biosensing. We optimized gold nanoring arrays such that the extinction peak position is inside the proposed window, the extinction peak is sharp enough to track the peak shift with high resolution and the figure of merit (sensitivity/linewidth) of the array is optimized at the same time. The peak-sharpening effect of the …
Periodic Arrays Of Gold Nano-Disks Coupled With Evanescent Spectroscopy, Hao Jiang, Touraj Manifar, Aref Bakhtazad, Hossein Hojjati, Jayshri Sabarinathan, Silvia Mittler
Periodic Arrays Of Gold Nano-Disks Coupled With Evanescent Spectroscopy, Hao Jiang, Touraj Manifar, Aref Bakhtazad, Hossein Hojjati, Jayshri Sabarinathan, Silvia Mittler
Physics and Astronomy Publications
We study and analyze various spectral features of gold nano-disk arrays coupled with the evanescent field of an optical waveguide using finite difference time domain simulations for comparison to our previous work on this topic (Jiang et al, Journal of Lightwave Technology 27, no.13, (2009): 2264-2270). We find that the quadrupolar and dipolar peaks are both heavily dependent on the coherent interactions of the periodic array and show comparable performance for refractive index sensing applications. We also find sharp extinction peaks and dips in the simulated spectra, but they are not sensitive to the index change of the surface-bound layer. …
A Biosensor Based On Periodic Arrays Of Gold Nanodisks Under Normal Transmission, Hao Jiang, Tingjie Li, Erden Ertorer, Jun Yang, Jayshri Sabarinathan, Silvia Mittler
A Biosensor Based On Periodic Arrays Of Gold Nanodisks Under Normal Transmission, Hao Jiang, Tingjie Li, Erden Ertorer, Jun Yang, Jayshri Sabarinathan, Silvia Mittler
Physics and Astronomy Publications
We present a biosensor based on periodic arrays of gold nanodisks patterned on top of a glass substrate. The sensor’s resonance wavelength, peak linewidth and figure of merit were studied both in experiments and in simulations. We analyzed the dependence of the sensor’s resolution on the inherent figure of merit of the sensor structure and the signal to noise ratio of the detection system. The best achieved refractive index resolution is 1.5×10-4 RIU and the detection limit on and antigen-antibody binding is better than 1 ng/mL.
Orientation Distribution Of Highly Oriented Type I Collagen Deposited On Flat Samples With Different Geometries, Qamrun Nahar, David Minh Luan Quach, Behafarid Darvish, Harvey A. Goldberg, Bernd Grohe, Silvia Mittler
Orientation Distribution Of Highly Oriented Type I Collagen Deposited On Flat Samples With Different Geometries, Qamrun Nahar, David Minh Luan Quach, Behafarid Darvish, Harvey A. Goldberg, Bernd Grohe, Silvia Mittler
Physics and Astronomy Publications
The structural arrangement of type I collagen in vivo is critical for the normal functioning of tissues, such as bone, cornea, tendons and blood vessels. At present, there are no established low-cost techniques for fabricating aligned collagen structures for applications in regenerative medicine. Here, we report on a straightforward approach to fabricate collagen films, with defined orientation distributions of collagen fibrillar aggregates within a matrix of oriented collagen molecules on flat sample surfaces. Langmuir Blodgett (LB) technology was used to deposit thin films of oriented type I collagen onto flat substrates exhibiting various shapes. By varying the shapes of the …