Here we present a method for rapid detection of the repetitive DNA sequences, based on the well-established TaqMan qPCR technique, modified and adapted for use with highly sensitive magnetic modulation biosensing (MMB) detection system. Proposed methodology significantly reduces the time required for detection of the DNA of interest. We have implemented the developed method for in ovo chick sexing of the domestic chicken (Gallus gallus) in an extremely short time frame of ~13 minutes, which is 4-9 times faster than any other commercially available testing method. The proposed method has broad applicability in agriculture, industry, bio-medical research and clinical diagnostics.

Detection of biomarkers at low concentrations is essential for early diagnosis of numerous diseases. In many sensitive assays, the target molecules are tagged using fluorescently labeled probes and captured using magnetic beads. Current devices rely on quantifying the target molecules by detecting the fluorescent signal from individual beads. Here, we propose a compact fluorescence-based magnetically aggregated biosensors (MAB) system. Using the device to detect human Interleukin-8, we demonstrated a 0.1 ng/L limit of detection and a 4-log dynamic range, performance which is on par with the most sensitive devices, but is achieved without their bulk and cost.

Current techniques for identification of protein-DNA interactions are hampered by limited dynamic range, DNA sequence length and high cost. Here, we detect protein-DNA interactions using a magnetic modulation biosensing (MMB) system. We validated a known interaction between a transcription factor and its corresponding DNA binding site and determined the previously unknown dissociation constant of this interaction. Compared to the commonly used gel electrophoresis mobility shift assay, we used short fluorescently labeled DNA fragments. Our method uses a simple short protocol and is cost-effective. We anticipate that the MMB-based technique will significantly advance the detection of protein-DNA interactions in bio-medical research.

To make transformative leaps in human health and wellness, our approach to healthcare must leverage new technologies, both hardware and software. This presentation will discuss a recently developed instrument for measuring the elasticity of living tissue, allowing multi-parameter analysis. Inspired by conventional mechanical compression testing, the portable instrument replaces the conventional pressure sensor with an array of optical fiber polarimetric sensors to improve both the resolution and sensitivity. These improvements allow the mechanical properties of unprocessed, living tissue to be analyzed. To date, animal tissue samples have been measured, and micron-scale mechanical deformation behavior has been detected, in agreement with the tissue architecture.

Detection of antibodies in the blood is an important clinical technique for diagnosing active infections and previous exposures. The grating-coupled fluorescent plasmonics (GC-FP) biosensing platform has been used to detect Lyme disease serum antibodies in patients and has been shown to be more sensitive than the current standard tests. In this study, we sought to design an affordable GC-FP detection system without sacrificing the sensitivity of data output. We further optimized our analysis strategies to achieve highly sensitive and consistent diagnostic results. This work ultimately aims to fill an unmet need for better detection of human Lyme disease.

All-dielectric resonant metasurfaces are emerging as a new platform enabling novel ways of light manipulation and new nanophotonic device architectures. In particular, in such two-dimensional nanoengineered surfaces, high-quality factor (high-Q) resonances can be achieved creating the so-called supercavity modes. In this work, we utilize these unique properties of high-Q dielectric metasurfaces for massively parallel label-free and non-destructive detection biomolecules on a hyperspectral imaging setup. We show detection of less than three molecules per square micrometer. Our novel technique together with the smart data science tools can unleash the full potential of next-generation platforms of efficient optical sensing metadevices.

We use frequency-locked microtoroid optical resonators to detect protein biomarkers at attomolar to femtomolar concentrations depending on the target. We validate these results against existing sensing technologies. In addition, we present new designs to further improve our sensing platform, including alternative light coupling strategies based on plasmonic nanoparticles for increased portability and new hybrid-microcavity designs for enhanced sensitivity. We anticipate that these designs will enable ultra-sensitive, rapid, selective, and portable diagnostics. In addition, we believe that our results demonstrating detection in real patient samples constitute a significant step forward in the optical whispering gallery mode biosensing field.

Environment, health and safety have an increasing need for sensitive, selective and inexpensive sensors. For such applications, we studied optical microring resonators based on polymers for in-situ, real-time detection of target analytes. One of the main sensing modes is volume detection enabling absorption spectroscopy for analyte-specific colorimetric reactions. Few studies in the literature have addressed the performance of optical microring resonators for absorption spectroscopy. We propose an analytical model to provide guidelines for optimizing ring resonator used for absorption spectroscopy in order to reach maximum sensitivity, including a study on the enhancement of the evanescent field using nano-structuring of the waveguide.

Accurate measurement of Amyloid-β biomarkers in blood serum has been highly sought after for early detection of Alzheimer’s Disease (AD). However, non-specific binding and low levels of Amyloid-β in blood pose a problem for traditional immunoassays. Here, we propose a lipid-functionalized biosensor for real-time, label-free detection of Amyloid-β by interaction with whispering gallery modes (WGM) of a microtoroid optical resonator. Non-specific binding is reduced by uniform surface coverage of the lipid, and protein-lipid interactions enhance the shift in resonance frequency. The lipid surface functionalization scheme enables increased accuracy and sensitivity of Amyloid-β and potential for blood-based screening of AD.

In this paper the sensing response of a packaged glass bottle microresonator is demonstrated. Bottle structures support whispering gallery modes along their curvature profile where a highest quality (Q) factor of 7.4×10^6 at 1550 nm is found in air. A simple and robust 3D-printed package is proposed for temperature and refractive index experiments. A temperature sensitivity of 10.5 pm/K is obtained with a packaged taper-bottle system. Such a system is partially encapsulated, enabling a free-vibration package solution. Preliminary results show a bulk refractive index sensitivity of 12 nm/RIU under a constant temperature of 22°C.

Ring resonators fabricated in silicon or silicon nitride constitute one of the most versatile and widely studied platform photonic technologies for biosensing. As part of an effort by AIM Photonics to advance the photonics manufacturing infrastructure of the United States, we have designed, fabricated, and tested a series of silicon nitride ring resonators for biosensing. Optimized designs will be incorporated into the AIM Photonics photonic design kit (PDK) and made available to the broader community. This talk will describe the evolution of our designs and their performance, with a particular focus on the detection of cytokines under microfluidic flow.

In this research we present a novel configuration allowing to perform high precision sensing of various vital bio-signs obtained from a fiber-based sensor performing the measurements in a non-tight contact with the skin of the measured subject. We will discuss usage of various types of fibers: single as well as multi-mode. Laser beam is injected into the fiber. In the case of a single mode fiber along the fiber, special artifacts that are breaking the total internal reflection condition, are inserted. Those artifacts are causing to some portion of the injected light to escape the fiber and to interact with the nearby surrounding of the fiber, realizing a smart photonic drip. Changes in the resulted interference-based intensity at the output of the fiber-sensor is analyzed and associated with various bio-medical signs. In the case of a multi-mode fiber, a detector analyzes the temporal-spatial changes of the 2-D speckle pattern imaged at the tip of the fiber.

We propose to develop a Vernier effect digital sensor from three fiber Bragg gratings. A sensing head in the form of a single mode tapered fiber is placed in one of the cavity. The cavity lengths are selected such that the ratio of optical path length of the two cavities follows a mathematical relationship provided in the long paper. We show, via simulations, that our digital sensor has the detection limit of 3 x 10-6 RIU which is almost three times of what was previously proposed with cascaded ring resonators.

Biosensing at 1550nm is highly attractive due to availability of a wide range of off-the-shelf and cost effective components to develop a viable biosensor. Here, we present a novel biosensor that employs phase shift-ring down measurement approach in a fiber cavity that also includes an amplifier. We analyzed the potential of the proposed biosensor by conducting refractive index measurements using various concentrations of sugar solutions. We found that the sensitivity and detection limit of the sensor are 2600o/RIU and 1.11 x 10-5 RIU respectively. We anticipate that the present work will find wide applications in realizing sensitive, portable, and cost effective biosensors.

Morphological parameters of biological nanoparticles (BNPs) have strong implications on their fate and functionality in vivo e.g., circulation, biodistribution, and clearance. Although interferometric scattering microscopy modalities have demonstrated the label-free detection of sub-100 nm BNPs including viruses and exosomes; they have an insufficient spatial resolution roughly limited to the illumination wavelength. Here, we introduce computational imaging to interferometric scattering microscopy with asymmetric illumination and demonstrate a two-fold resolution enhancement. We demonstrate high-resolution imaging of nanoparticles across a large field-of-view of 100 µm × 100 µm. This novel imaging platform enables ultrasensitive and label-free morphological visualization of low-index sub-diffraction-limited BNPs in a high-throughput manner at subwavelength resolution.

We describe a biosensing module in which the core sensing elements are bacteria that were genetically “tailored” to generate bioluminescence in response to the presence of a chosen target material. The module which implements a special detection methodology for overcoming signal variations incurred by the bacteria, and varying environmental operating conditions, operates in-situ outdoors as an autonomous network element designed for large scale deployment. The module described herein was developed for the detection of buried landmines by sensing the dinitrotoluene vapors released by the mine, and leak to the ground. Detection of DNT concentrations in the ppm range was demonstrated.

Recently the single molecule sensor device has been developed by using an electrical detection technique. However, considering the nanoscale bio-sensors are utilizing the optical detection technique, we have fabricated Au nanopores by using FIB and electron beam irradiation techniques. Furthermore, considering the facts that carbon pore membrane consists of the ~ 5 nm wide slits, and inevitable carbon incorporation with Au atoms during electron beam irradiations, fabrication of the Au-C mixture slit nanopore would be desirable. Hence, In this report, we would address the fabrication process of nanoscale pore slit on the 200 nm thick Au film.

A lot of individuals residing in resource limited settings where timely access to medical care is a challenge and healthcare infrastructure is usually poor have no access to laboratory facilities. Disease diagnosis in such sites is dependent on the presence of point-of-care (POC) devices. These POC diagnostics play a key role in ensuring rapid patient care because they are simple to use, inexpensive, portable, instrument independent and do not require a trained technician to operate. In this study, we used a smartphone camera as a spectrometer for measurement of Enzyme Linked Immunosorbent Assays (ELISA) at clinically relevant concentrations. The HIV-p24 ELISA and Rhodamine were used as the analytes of choice for proof of concept purposes. The smartphone platform was able to detect the absorption within the visible spectral range from 400 to 700 nm. The results obtained showed that the performance of the smartphone based platform correlates with the conventional microplate reader.

Deep learning is a class of machine learning techniques that uses multi-layered artificial neural networks for automated analysis of signals or data. The name comes from the general structure of deep neural networks, which consist of several layers of artificial neurons, each performing a nonlinear operation, stacked over each other. Beyond its main stream applications such as the recognition and labeling of specific features in images, deep learning holds numerous opportunities for revolutionizing image formation, reconstruction and sensing fields. In this presentation, I will provide an overview of some of our recent work on the use of deep neural networks in advancing computational microscopy and sensing systems, also covering their biomedical applications.

When dealing with sensing of (bio)molecules the length scale of targets may vary over more than 2 orders of magnitude moving from elementary ions and molecules (about 0.1 to 1 nm) to complex proteins and virus (about 1 to 100 nm). Several technologies have been proposed to prepare fluidic structures and systems with length-scales matching those of the molecular target. Among these, electrochemical micro and nano structuring of silicon is increasingly attracting attention for biosensing and microfluidics. In this talk, state-of-the-art research on silicon nano-micro structures and systems prepared through electrochemical etching for high-sensitivity (bio)sensing, among which, nanostructured devices for ultra-high-sensitivity ion measurements in water, nanostructured optical platforms for point-of-care clinical diagnostics, drop-and-measure photonic crystal systems for in-field optical biosensing, microneedles for transdermal electrochemical biosensing, is presented and discussed.

We report the use of peptide-based capture agents as an alternative to antibodies and nucleic acid-based bioreceptors for porous silicon biosensors. Click chemistry is employed to attach azide-functionalized peptides to alkyne-modified porous silicon films. Details regarding the attachment of a streptavidin binding peptide and the subsequent detection of streptavidin molecules will be discussed. Optical reflectance measurements and FTIR spectra will be presented.

Optical racetrack micro-resonators (OMR) allow the implementation of compact, robust and sensitive biosensors. The OMR presented here is based on polymer materials with vertical coupling between the bus and the ring waveguides. For future industrial fabrication of a low-cost and portable device, the system includes a distributed feedback laser tuned by adjusting the temperature and injection current. For volumetric sensing of diluted glucose aqueous solution, a microfluidic cell is bonded to the surface. It leads to a sensitivity of 31 nm/RIU and a LOD of 6.5x10 -6 RIU.

Biological macromolecules such as antibodies, enzymes, proteins and aptamers have good molecular recognition ability which makes them good candidates for biosensing applications. In this study, glass substrates were treated with silane in order to immobilize HIV gp41 antibodies on their surfaces. The HIV pseudovirus was added to the treated substrates followed by addition of antibodies conjugated to nanoparticles. The surfaces were characterised by using water contact angle, atomic force microscopy (AFM) and Raman spectroscopy. Our preliminary data displayed that the antibodies were indeed immobilized on the glass substrates which made it possible for capturing the intact HIV pseudovirus. Further, Raman spectroscopy revealed the presence of disulphide bonds indicating successful conjugation of the HIV gp41 antibodies to the HIV pseudovirus.

We combine gold nanoslit array (GNA) with vertical cavity surface emitting lasers (VCSELs) to realize a prototype of miniaturized high sensitivity chemical/biosensor.The advantage of such chips includes compact size, low cost and low power consumption, long life time, stable performance, easy to make array and multi-flux test, and label-free sensing. The finite difference time domain (FDTD) method is employed to model the transmission signal from the chips. The sensitivity of 106 nW/RIU is reached and the exosome interaction experiment is adopted to verify the surface binding reaction. It is believed that the biosensor chips have potential applications in health care, clinical diagnostics, environmental monitoring, and cancer biomarker testing.