Plasmonic resonance energy transfer (PRET) based imaging has been proposed as an effective label-free real-time biomolecular absorption spectroscopic method that enables the detection of biomolecules and dynamic cell activities. Here, we present a metasurface-based PRET-imaging platform that effectively engineers the darkfield scattering spectrum using the gap plasmon and grating effect. As a demonstration, three different biomolecules (Cyt c, Chl a, Chl b) are simultaneously detected using our metasurface-based PRET-imaging platform. Our proposed metasurface-based PRET-imaging platform enables continuous monitoring in the spatial region and multiplexed PRET sensing of multiple biomolecules with different absorption spectrums in the visible.
Publisher's Note: This paper, originally published on 11/5/2018, was replaced with a corrected/revised version 11/15/2018. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.
We present some recent developments using smart optical tools, such as optical fiber tweezers (OFTs) and plasmonic optical antennas, to explore the biological world. Using OFTs, which act as a smart light touch, we realized the stable trapping and flexible manipulation of single particles, bacteria, and cells. The trapping and multifunctional manipulation is demonstrated using different samples varying from mammalian cells to bacteria, nanotubes and to biomolecules, with sizes changing from several tens of micrometer to a few nanometer. The OFTs is also used for the stable trapping and patterning of multiple particles and cells, with the ability of biophotonic waveguides formation based on bacteria. In addition to the trapping and manipulation of cell individuals, we also demonstrated that smart optical tools, such as plasmonic optical antennas, are capable of cellular exploration.
The Al Nano apertures surrounded by periodic patterns on the pyramidal structures were fabricated. The nanometric size aperture with ~ 100 nm diameter surrounded by equidistant elliptic groove patterns presented greater transmission than the aperture with circular groove patterns. The translocation of λ-DNA through these fabricated nanostructures was tested using electrically biased techniques. We observed the strong fluorescent optical signal from the translocated DNA through the nanoprobe with a charge coupled device camera. The optical force driven DNA translocation though a nanoprobe surrounded with elliptically patterned grooves is under investigation.
We microfabricated the plasmonic nanopore with ~ 1 nm on top of the pyramid for single molecule dynamics. This
plasmonic micro device provides huge photon transmission through the fabricated nanochannel on the top of the
pyramidal structure. This can generate the huge photonic pressure gradient between the free space and nanopore inside.
The huge pressure gradient can be attributed to the resonance transmission between the fabricated V groove cavity and
the nanosize waveguide formed during the metal deposition. This fabricated huge photonic device can be utilized as biomolecule
translocation and single molecule dynamics.
The localized surface plasmon resonance (LSPR) of a nanoplasmonic particle is often considered to occur at a single
resonant wavelength. However, the physical measures of plasmon resonance, namely the far-field measures of
scattering, absorption, and extinction, and the near-field measures of surface-average or maximum electric field
intensity, depend differently on the particle polarizability, and hence may be maximized at different wavelengths. We
show using analytic Mie theory that the differences in peak wavelength between the near- and far-fields can reach over
200 nm for nanoparticle sizes commonly used in spectroscopy applications. Using finite element analysis, we also
consider the effect of varying particle shape to spheroidal geometries, and consider polarization dependence. Using the
quasi-static and extended quasi-static approximation, we show that the differences between the near- and far- field
measures of plasmon resonance can be largely explained by radiation damping effects. We suggest that accounting for
these differences is relevant both for optimizing device design, and for improving fundamental understanding of surface-enhanced
mechanisms such as surface-enhanced Raman spectroscopy (SERS).
While technology relies on components defined in a fixed position on a rigid substrate, nature prefers soft substrates, and
allows components to move significantly during morphogenesis. Taking inspiration from biological fabrication, we have
developed a technique, called active polymer nanofabrication, which utilizes thermally active polymers to create
complex nanoplasmonic substrates designed for molecular detection. We demonstrate the ability of active polymer
nanofabrication to create ultra-dense nanoplasmonic prism arrays (plasmonic nanoflowers), and correlate changes in
array morphology with optical properties. We investigate the associated changes in local electromagnetic fields with
finite element analysis. Finally, we demonstrate the ability of active polymers to deform macroscopically while retaining
nanostructure morphology. We expect these properties will make active polymer nanofabrication useful for a wide range
of nanoplasmonic devices.
We have invented a novel all-optical-logic microfluidic system which is automatically controlled only by visible or near infrared light with down to submilliwatt power. No electric power supply, no external or MEMS pump, no tubings or connectors, no microfluidic valves, nor surface patterning are required in our system. Our device only consists of a single-layer PDMS microfluidic chip and newly invented photoactive nanoparticles. Our photoactive nanoparticles are capable of converting optical energy to hydrodynamic energy in fluids. The nanoparticle themselves are biocompatible and can be biofunctionalized. Via these photoactive nanoparticles, we used only light to drive, guide, switch and mix liquid in optofluidic logic circuits with desired speeds and directions. We demonstrated the optofluidic controls in transportation of biomolecules and cells.
An electron transfer pathway between Cytochrome c (Cyt c) molecules, a 30nm Au nanoparticle and an ITO working electrode in an electrochemical cell is constituted by molecular junctions. The scattering spectrum of single Au nanoparticle is measured simultaneously with the cyclic voltammogram. The plasmon resonance wavelength and the scattering cross section of the single Au nanoparticle are affected by the redox reactions of less than 200 cyt c molecules on its surface and exhibit cyclic variations. The electron shuttling between Cyt c molecules and ITO electrode through the Au nanoparticle in the redox process as well as the conformation change of the Cyt c molecules between ferric and ferrous states are accounted the reasons for the change of the plasmon resonance wavelength and scattering cross section. The presented study of the interaction of biological electron transporter protein and photonic nanostructure provide a nano-scale system to probe the electron transfer events in the biological system. It also has the implicational importance to the development of future hybrid bio-optoelectronic devices.
A gold nanowire array that we call nanorainbow SPR sensor array can be chemically functionalized and used to capture biomolecules. The localized plasmon resonance wavelength of the gold nanowires shifts on the biomolecule binding and reaction sites. The plasmon resonance shift of the gold nanorainbow is sensitive to the biomolecule immobilization in sub-nM concentration. As an application example, label-free oligonucleotide hybridizations are detected on the nanorainbow sensor in a multiplexed microfluidic chip.
Sub-lithographic nanowires and nanogaps were fabricated by spacer lithography (size reduction technology), which is a parallel processes for nanometer pattern generation on a wafer scale with resolution comparable to the best electron beam lithography. Sub-10nm line width is defined by using a sacrificial ultrathin film deposited by low pressure chemical vapor deposition (LPCVD), in a process similar to formation of gate sidewall spacers in CMOS processing. Furthermore, a novel method called iterative spacer lithography
(ISL) is demonstrated by alternating materials and repeating the spacer lithography multiple times in order to multiply the pattern density. Silicon structures with sub-10nm width fabricated by this process were used as a mold in nanoimprint lithography and lift-off patterning of sub-30nm platinum nanowires for use as model catalyst systems. A similar process called reversed spacer lithography (RSL) is demonstrated to form sub-10nm nanogap device and fluid channels in poly-Si. This nanogap device provides a label-free tool for DNA
hybridization detection based on measuring capacitance changes in the gap.
One of the key issues in the development of IR focalplane
systems is the need for low-noise and low-power read-
out circuitry which is compatible with the detector technology.
Superconductive circuitry offers several advantages
over more conventional circuitry. These include much lower
power consumption and the possibility of unique circuit
topologies relevant for developing advanced monolithic
detectors. On-chip signal processing through A/D conversion
with digital gamma-ray suppression and digital integration
appears possible. This paper reviews the progress that TRW
has made in developing several of the key components of such
a superconductive read-out system. We have developed a semi-
conductor/Josephson-junction 3-terminal device for direct
interfacing to semiconductor detectors as well as thin-film
superconductive detectors. The 3-terminal device has a current
gain of : 500 and provides an optimum interface to further
superconductive stages. Performance when coupled to a SQUID
read-out will be discussed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.