This PDF file contains the front matter associated with SPIE Proceedings Volume 12663, including the Title Page, Copyright information, Table of Contents and Conference Committee list.

In optical trapping of gold (Au) nanoparticles (NPs) at a glass/solution interface, initially NPs align in the manner of optical binding not only inside but also outside of the focused trapping site. Further gathering and assembling of more NPs lead to the formation of their dynamically moving and fluctuating assembly like a flying group of bees in air. Since we found this phenomenon, we have been systematically studying its dynamics and mechanism. It shows clear dependence on trapping laser polarization. The assembling and swarming expand linearly with the direction perpendicular to linear laser polarization, giving a dumbbell shape morphology, while a disk like one is prepared for circularly polarized laser. The morphology and the size of such assemblies can be controlled by tuning optical, physical, and chemical parameters based on the intrinsic surface plasmon resonance properties of Au NPs. We demonstrate new appearance of two swarms with ellipse and ring distribution of NPs by shifting the axial position of the trapping laser focus with respect to the interface. The contours of the dumbbell shape can be controlled by the incident and focusing angles of the trapping laser. Upon using the Au NPs with different size, shape, and structures, surprisingly unique dynamic behavior is observed. Further we introduce nanolithographically fabricated gold nanopattern as a glass interface, showing a new control way of the swarming morphology. These results show high potential of “optically evolved assembling and swarming” in the studies on nanophotonic machine.

The fundamental processes of absorption, stimulated and spontaneous emission, and elastic as well as inelastic scattering involving light and atoms, molecules, and nano-particles have been studied for decades using both classical and quantum theories. While providing an overview of the subject, this paper presents a streamlined approach to studying atom-photon interactions in the context of modern quantum optics in the hope of providing guidance for applications in the general area of molecular and nano-photonic machines.

Two photon lithography (TPL) is a versatile method for the fabrication of photonic structures based on photoresist materials. Structures producing vivid colors in transmission or reflection can be achieved. Combining TPL with smart hydrogels opens the route to reversible sensors for a wide range of external stimuli. The printing resolution for TPL can reach 300 nm. As the scale of the smart hydrogel is decreased from the millimeter to the micron level, its actuation speed can be increased many-fold. Herein, we report on a square spiral shaped vapor responsive hydrogel photonic structure. The structural color is shown to be reproducible and reversible under exposure to water, ethanol, IPA and acetone vapor. The influence of the fabrication laser power on the structure dimension and vapor responsivity are also demonstrated, with structures fabricated using a higher laser power producing a larger vapor sensitive spectral response. Finite difference time domain simulations accurately predict the structural color and confirm expansion of the structure when exposed to the vapors is the dominant contribution for the color transformation. Structures for pattern transformation and encryption are also demonstrated.

It has been known for two centuries that starch turns blue upon exposure to iodine as well as iodine and iodide. Starch contains branched-chain polysaccharides (amylopectin) and linear polysaccharides (amylose), the latter a linear polymer of a-D-glucose units joined by a (see manuscript PDF for symbol) linkages. Amylose forms a linear helix with 6 a-D-glucose units per turn (i.e., one “amylose ring”) and one iodide atom bound maximally per turn. Despite extensive work, suitable quantitative data of iodide–amylose binding seemed surprisingly scarce. To fill an apparent lacuna, examination of the intrinsic binding affinity of amylose for iodide (with measurement of “blue values” by absorption spectroscopy) via a factorial design (grid) study showed that >70% occupancy of amylose occurs with [iodide] in the range 0.05 – 0.5 mM and [amylose rings] in the range 0.3 – 1 mM. The required concentrations of both species set limits on possible applications. The incorporation of multiple amylose molecules into matrices was examined by reductive amination of the aldehyde terminus with an amine bearing a cross-linkable group. Subsequent cross-linking afforded molecular architectures albeit in quite low yield. A challenge in this domain concerns purification and characterization of synthetic products. The stability of amylose toward degradation by amylase enzymes was examined in the presence of amylase inhibitors. Taken together, the work establishes the foundation and prospective limits for use of amylose for scavenging iodide.

One of the most critical issues in the field of molecular diagnostics and medicine is the development of compact and sensitive assay devices for the precise detection of nucleic acids. Although there are several effective methods for detecting unique nucleic acid sequences, the high cost of equipment and reagents, as well as the need for highly trained personnel, necessitate the design of new and more affordable diagnostic assays that are comparable in selectivity and sensitivity to existing methods that can be used in developing countries and/or outside of specialized diagnostic laboratories. Sensing methods based on guanine quadruplexes (G-4)/hemin complexes, that have peroxidase activity are one of the promising directions for the detection of target nucleic acids. Target nucleic acid was analyzed by peroxidase-like DNA-nanomachine (PxDm) equipped with 1-3 long analyte binding arms to tightly bind and unwind single-stranded analytes. In this study, we present a technique for sequence-specific detection of nucleic acid. The technique is based on the measuring of a chemiluminescent (CL) emission induced by luminol oxidation utilizing a closed-type detection device. Moreover, the optical properties and potential use of plasmonic silver nanoparticles (Ag NPs) to enhance the CL intensity of chemiluminophore were investigated. Particular attention was paid to the possibility of synthesizing the silver nanoparticles with different spectral positions of plasmon resonance band, depending on the method and duration of synthesis. The CL intensity of luminol in the presence of the post-centrifuged colloidal Ag NPs obtained by laser ablation has been increased 3 times. The combination of AgNPs-luminol-DNA-nanomachine systems in the presence of a target analyte led to the significant increase of limit of detection and reached clinically relevant quantitative indications.