1,720,969 research outputs found
Broadband energy-entangled photon for high resolution temporal sensing
No full textEnergy-time entangled photon pairs exhibit at the same time narrowband and short time features. We show how to make use of those quantum properties to realize measurements beyond the capabilities of classical devices. As proof of principle experiment we show imaging through a scattering medium by selecting the ballistic photons only, using optical coincidence measurements
Deep learning augmented nanoplasmonic infrared sensor for structural protein biomarker-based detection of neurodegenerative diseases
No full textWe introduce an infrared metasurface sensor based on plasmonic surface-enhanced infrared absorption spectroscopy combined with immunoassay, which detects alpha-synuclein, an early structural biomarker protein for neurodegenerative diseases with clinical specificity and identifies its different structural species using their unique spectroscopic signals. Unprecedentedly, we augmented the sensor with a Deep Neural Network, enabling quantitative differentiation of alpha-synuclein aggregates. Capable of multiplexing and retrieving aggregate signatures from complex biomatrix, our sensor shows promise for neurodegenerative disease diagnosis, disease progression monitoring, and drug efficacy assessment.BIOSLMN
Computational study for optimization of a plasmon FET as a molecular biosensor
No full textSurface Plasmon Resonance (SPR) is currently being widely studied as it exhibits sensitive optical properties to changes in in the refractive index of the surrounding medium. As novel devices using SPR have been developing rapidly there is a necessity to develop models and simulation environments that will allow for continued development and optimization of these devices. A biological sensing device of interest is the Plasmon FET which has been proven experimentally to have a limit of detection (LOD) of 20pg/ml while being immune to the absorption of the medium. The Plasmon FET is a metal-semiconductor-metal detector which employ functionalized gold nanostructures on a semi-conducting layer. This direct approach has the advantages of not requiring readout optics reducing size and allowing for point-of -care measurements. Using Lumerical FDTD and Device numerical solvers, we can report an advanced simulation environment illustrating several key sensor specifications including LOD, resolution, sensitivity, and dynamic range, for a variety of biological markers providing a comprehensive analysis of a Direct Plasmon-to-Electric conversion device designed to function with colored mediums (eg.whole blood). This model allows for the simulation and optimization of a plasmonic sensor that already o
ers advantages in size, operability, and multiplexing-capability, with real time monitoring
Plasmonic sensor for troponin I detection using whole blood (Conference Presentation)
No full textSurface Plasmon Resonance (SPR) has been widely studied for various application. Due to the highly sensitive optical property to the change of the refractive index of the surrounded medium, there have been lots of reports for biological sensing. Direct Plasmon-to-Electric conversion device using metal nanostructures and semiconductor does not require additional readout optics and the device size and sensing area could be much smaller (1/100 to 1/10 of size) than current technologies. In addition, our sensing platform designed to address the issue of using the colored medium (e.g. whole blood) for detection. The detection signal comes only from plasmonic absorption and is not affected by the absorption from the medium. We developed a plasmonic sensing platform using a metal-semiconductor-metal detector by incorporating gold nanostructures on top of the semiconducting layer. The gold nanostructures are functionalized using antibodies to detect Troponin I, which is very important molecule to prevent hart attacks. In this presentation, we report a successful demonstration of a point-of-care sensing platform to detect cardiac Troponin I using antibody functionalized plasmonic nanostructures. Because the sensors are integrated into a microfluidic channel, it requires only a few µl of sample volume. The limit of detection was 20 pg/ml in our preliminary results, and we successfully demonstrated sensor operation using whole blood. This plasmonic sensor has several advantages such as extremely small size for the point-of-care system, multiplexing capability, no need of complex optical geometry and real-time binding monitoring
Estimation of the rate of entangled-photon-pair interaction with metallic nanoparticles based on classical-light second-harmonic generation measurements
No full textEntangled-photon-pair interaction (EPPI) with matter is a key element in many suggested quantum-light applications and an enhancement of this interaction is of great importance. In this paper, we suggest and investigate the use of metallic nanoparticles (MNPs), with their exceptional capability of light–matter coupling at their localized surface plasmon resonance, for a potential enhancement of EPPI. We specifically investigate second-harmonic generation and theoretically estimate the rate of EPPI with MNPs using measurements with classical-light. We perform a simple measurement based on approximating the optical-setup factor G, of hyper-Rayleigh scattering. Experimental results, obtained for solutions of silver NPs (SNPs) with different densities, show a hyperpolarizability of about The results indicate that the use of SNPs can indeed be advantageous for EPPI, with an estimated three orders-of magnitude enhancement of the hyperpolarizability, relative to the best organic molecules. However, we show that further optimization of the SNPs should be carried out to enlarge their EPPI cross-section even more
A practical theoretical framework for optimizing spontaneous super-resolution on confocal microscopes (Conference Presentation)
No full textCell-surface affinity sensors for identifying and selecting highly cytokine-secreting cells (Conference Presentation)
No full textBiophotonic nanostructured translational implants for remote intraocular pressure sensing (Conference Presentation)
No full textWhile numerous multifunctional antifouling nanostructures on insect wings have been previously studied and replicated, their potential incorporation into implantable medical devices remains unexplored. We have demonstrated the use of multifunctional bioinspired nanostructured membrane inspired by transparent butterfly wings for intraocular pressure (IOP) sensing in vivo. [1]. We investigated the multifunctional properties of the biophotonic nanostructures found on the wings of the longtail glasswing (C. faunus) butterfly. The AFM, SEM, optical, and biological characterizations have revealed that two groups of dome-shaped nanostructures with different periodicity co-exist on the transparent wings of the C. faunus: (1) angle-independent anti-reflective nanostructures with periods of 140-180 nm in the postdiscal areas; (2) angle- independent transmissive light-scattering nanostructures with periods of 200-300 nm in the basal areas. In vitro testing has revealed both regions displayed antifouling properties based on physically-induced cell lysis. We have (1) adapted the coherence-preserving angle-independent transmissive light-scattering property of the basal nanostructures that could make optical sensors such as Fabry Perot (FP) resonators more angle-independent; and (2) by further engineering the basal nanostructures, created bioinspired nanostructures (BINS) that would prevent biofouling without inducing cell lysis and suppress inflammation. To produce BINS with periods of 385-505 nm on a Si3N4-membrane, we used a polymer-phase separation process following the nature’s way of forming nanostructures [2,3]. Angle- resolved transmission spectroscopy showed that the light transmission of the BINS-integrated membrane was twice more angle-independent than a flat Si3N4-membrane. In a series of in vitro studies the BINS-integrated Si3N4 surface displayed remarkable anti-biofouling properties against proteins (albumin and streptavidin, ***P ≤ 0.001), prokaryotes (E. coli, **P ≤ 0.01), and eukaryotes (HeLa cells, ***P ≤ 0.001) when compared to flat Si3N4 and control (glass) surfaces. Finally, we integrated BINS onto the FP-resonator-based IOP sensor that was recently developed in our lab [4]. However, its practical applications were limited by its narrow readout angle inherent to FP-resonators and infrequent but severe biofouling observed after long-term implantation. The BINS integration onto the IOP sensor led to a 2.5-fold improvement in readout angle allowing easy handheld monitoring and in a one-month in vivo study conducted in rabbits, showed a 3-fold reduction in IOP error and 12-fold reduction in tissue encapsulation and inflammation, compared to an IOP sensor without BINS
Highly sensitive protein detection using a plasmonic field effect transistor (Conference Presentation)
No full textLocalized surface Plasmon Resonance (LSPR) is a nanoscale phenomenon which presents strong resonance associated with noble metal nanostructures. This plasmon resonance based technology enables highly sensitive detection for chemical and biological applications. Recently, we have developed a plasmon field effect transistor (FET) that enables direct plasmonic-to-electric signal conversion with signal amplification. The plasmon FET consists of back-gated field effect transistor incorporated with gold nanoparticles on top of the FET channel. The gold nanostructures are physically separated from transistor electrodes and can be functionalized for a specific biological application. In this presentation, we report a successful demonstration of a model system to detect Con A proteins using Carbohydrate linkers as a capture molecule. The plasmon FET detected a very low concentration of Con A (0.006 mg/L) while it offers a wide dynamic range of 0.006-50 mg/L. In this demonstration, we used two-color light sources instead of a bulky spectrometer to achieve high sensitivity and wide dynamic range. The details of two-color based differential measurement method will be discussed. This novel protein-based sensor has several advantages such as extremely small size for point-of-care system, multiplexing capability, no need of complex optical geometry
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