scholarly journals Gradient Waveguide Thickness Guided-Mode Resonance Biosensor

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 376
Author(s):  
Jia-Ming Yang ◽  
Nien-Zu Yang ◽  
Cheng-Hao Chen ◽  
Cheng-Sheng Huang
Keyword(s):  
Optical Sensors ◽  
Spatial Information ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Optical Path ◽  
Fluorescence Measurement ◽  
Buffer Solution ◽  
Guided Mode ◽  
Path Design ◽  
Guided Mode Resonance

Portable systems for detecting biomolecules have attracted considerable attention, owing to the demand for point-of-care testing applications. This has led to the development of lab-on-a-chip (LOC) devices. However, most LOCs are developed with a focus on automation and preprocessing of samples; fluorescence measurement, which requires additional off-chip detection instruments, remains the main detection method in conventional assays. By incorporating optical biosensors into LOCs, the biosensing system can be simplified and miniaturized. However, many optical sensors require an additional coupling device, such as a grating or prism, which complicates the optical path design of the system. In this study, we propose a new type of biosensor based on gradient waveguide thickness guided-mode resonance (GWT-GMR), which allows for the conversion of spectral information into spatial information such that the output signal can be recorded on a charge-coupled device for further analysis without any additional dispersive elements. A two-channel microfluidic chip with embedded GWT-GMRs was developed to detect two model assays in a buffer solution: albumin and creatinine. The results indicated that the limit of detection for albumin was 2.92 μg/mL for the concentration range of 0.8–500 μg/mL investigated in this study, and that for creatinine it was 12.05 μg/mL for the concentration range of 1–10,000 μg/mL. These results indicated that the proposed GWT-GMR sensor is suitable for use in clinical applications. Owing to its simple readout and optical path design, the GWT-GMR is considered ideal for integration with smartphones or as miniaturized displays in handheld devices, which could prove beneficial for future point-of-care applications.

scholarly journals Direct and rapid measurement of hydrogen peroxide in human blood using a microfluidic device

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Gaikwad ◽  
P. R. Thangaraj ◽  
A. K. Sen
Keyword(s):  
Hydrogen Peroxide ◽  
Microfluidic Device ◽  
Human Blood ◽  
Blood Cells ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Time Interval ◽  
Fluorescence Measurement ◽  
Rapid Measurement ◽  
Automated Method

AbstractThe levels of hydrogen peroxide ($${\mathrm{H}}_{2}{\mathrm{O}}_{2}$$ H 2 O 2 ) in human blood is of great relevance as it has emerged as an important signalling molecule in a variety of disease states. Fast and reliable measurement of $${\mathrm{H}}_{2}{\mathrm{O}}_{2}$$ H 2 O 2 levels in the blood, however, continues to remain a challenge. Herein we report an automated method employing a microfluidic device for direct and rapid measurement of $${\mathrm{H}}_{2}{\mathrm{O}}_{2}$$ H 2 O 2 in human blood based on laser-induced fluorescence measurement. Our study delineates the critical factors that affect measurement accuracy—we found blood cells and soluble proteins significantly alter the native $${\mathrm{H}}_{2}{\mathrm{O}}_{2}$$ H 2 O 2 levels in the time interval between sample withdrawal and detection. We show that separation of blood cells and subsequent dilution of the plasma with a buffer at a ratio of 1:6 inhibits the above effect, leading to reliable measurements. We demonstrate rapid measurement of $${\mathrm{H}}_{2}{\mathrm{O}}_{2}$$ H 2 O 2 in plasma in the concentration range of 0–49 µM, offering a limit of detection of 0.05 µM, a sensitivity of 0.60 µM−1, and detection time of 15 min; the device is amenable to the real-time measurement of $${\mathrm{H}}_{2}{\mathrm{O}}_{2}$$ H 2 O 2 in the patient’s blood. Using the linear correlation obtained with known quantities of $${\mathrm{H}}_{2}{\mathrm{O}}_{2}$$ H 2 O 2 , the endogenous $${\mathrm{H}}_{2}{\mathrm{O}}_{2}$$ H 2 O 2 concentration in the blood of healthy individuals is found to be in the range of 0.8–6 µM. The availability of this device at the point of care will have relevance in understanding the role of $${\mathrm{H}}_{2}{\mathrm{O}}_{2}$$ H 2 O 2 in health and disease.

scholarly journals A Compact Detection Platform Based on Gradient Guided-Mode Resonance for Colorimetric and Fluorescence Liquid Assay Detection

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2797
Author(s):  
Jing-Jhong Gao ◽  
Ching-Wei Chiu ◽  
Kuo-Hsing Wen ◽  
Cheng-Sheng Huang
Keyword(s):  
Limit Of Detection ◽  
Detection System ◽  
Fluorescence Emission ◽  
Assay Sensitivity ◽  
Detection Range ◽  
Current Form ◽  
Guided Mode ◽  
Spectral Detection ◽  
Guided Mode Resonance ◽  
Colorimetric Assays

This paper presents a compact spectral detection system for common fluorescent and colorimetric assays. This system includes a gradient grating period guided-mode resonance (GGP-GMR) filter and charge-coupled device. In its current form, the GGP-GMR filter, which has a size of less than 2.5 mm, can achieve a spectral detection range of 500–700 nm. Through the direct measurement of the fluorescence emission, the proposed system was demonstrated to detect both the peak wavelength and its corresponding intensity. One fluorescent assay (albumin) and two colorimetric assays (albumin and creatinine) were performed to demonstrate the practical application of the proposed system for quantifying common liquid assays. The results of our system exhibited suitable agreement with those of a commercial spectrometer in terms of the assay sensitivity and limit of detection (LOD). With the proposed system, the fluorescent albumin, colorimetric albumin, and colorimetric creatinine assays achieved LODs of 40.99 and 398 and 25.49 mg/L, respectively. For a wide selection of biomolecules in point-of-care applications, the spectral detection range achieved by the GGP-GMR filter can be further extended and the simple and compact optical path configuration can be integrated with a lab-on-a-chip system.

Portable guided-mode resonance biosensor platform for point-of-care testing

2012 ◽  
Author(s):  
Gun Yong Sung ◽  
Wan-Joong Kim ◽  
Hyunsung Ko ◽  
Bong K. Kim ◽  
Kyung-Hyun Kim ◽  
...  
Keyword(s):  
Point Of Care ◽  
Point Of Care Testing ◽  
Guided Mode ◽  
Guided Mode Resonance

scholarly journals Development and Evaluation of Europium-Based Quantitative Lateral Flow Immunoassay for the Chronic Kidney Disease Marker Cystatin-C

2021 ◽  
Author(s):  
SATHEESH NATARAJAN ◽  
Ebru saatci
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Cystatin C ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Lateral Flow ◽  
Fluorescence Measurement ◽  
Analytical Sensitivity ◽  
Linear Calibration ◽  
Time Resolved

Abstract This study aimed to establish a Europium label time-resolved fluorescence immunoassay (TRFIA) to detect the chronic kidney disease (CKD) biomarker Cystatin-C. Some Cystatin-c immunoassays are sensitive, accurate, and available for clinical application, but they are expensive and time-consuming procedures. Also, conventional organic dye-based fluorescence lateral flow assay showed more background fluorescence interference and low analytical sensitivity. So this Europium-based sandwich immunoassay was developed to detect the concentration of cystatin-c in a urine sample with captured anti-cystatin-c antibodies immobilized on nitrocellulose membrane and then bonded with detection anti-cystatin-c labelled with CM-EU, followed by fluorescence measurement using time-resolved fluorometry in 15 minutes. The performance of this TRFIA was evaluated using the clinical urine serum and compared with the ELISA assays. The linear calibration range was 0.015-32 µg/ml, and the limit of detection (LOD) quantified was 0.0001µg/ml. This current work has improved the LOD of our previous work from 0.013µg/ml to 0.001µg/ml. These results indicated that the CM-EU nanoparticle-based LFIA is rapid, more sensitive, reliable, and reproducible for point-of-care testing of Cys-C concentrations in urine

scholarly journals Direct and Rapid Measurement of Hydrogen Peroxide in Human Blood Using a Microfluidic Device

2020 ◽  
Author(s):  
Ravindra Gaikwad ◽  
Paul Thangaraj ◽  
Ashis Sen
Keyword(s):  
Hydrogen Peroxide ◽  
Microfluidic Device ◽  
Human Blood ◽  
Blood Cells ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Time Interval ◽  
Fluorescence Measurement ◽  
Rapid Measurement ◽  
Automated Method

Abstract The levels of hydrogen peroxide (H2O2) in human blood is of great relevance as it has emerged as an important signalling molecule in a variety of disease states. Fast and reliable measurement of H2O2 levels in the blood, however, continues to remain a challenge. Herein we report an automated method employing a microfluidic device for direct and rapid measurement of H2O2 in human blood based on laser-induced fluorescence measurement. Our study delineates the critical factors that affect measurement accuracy – we found blood cells and soluble proteins significantly alter the native H2O2 levels in the time interval between sample withdrawal and detection. We show that separation of blood cells and subsequent dilution of the plasma with a buffer at a ratio of 1:6 inhibits the above effect, leading to reliable measurements. We demonstrate rapid measurement of in plasma in the concentration range of 0 – 49 µM, offering a limit of detection of 0.05 µM, a sensitivity of 0.60 µM-1, and detection time of 15 min; the device is amenable to the real-time measurement of H2O2 in the patient’s blood. Using the linear correlation obtained with known quantities of H2O2, the endogenous H2O2 concentration in the blood of healthy individuals is found to be in the range 2 – 6 µM. The availability of this device at the point of care will have relevance in understanding the role of H2O2 in health and disease.

scholarly journals Toward spectrometerless instant Raman identification with tailored metasurfaces-powered guided-mode resonances (GMR) filters

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed A. Mousa ◽  
Nadia H. Rafat ◽  
Amr A. E. Saleh
Keyword(s):  
Point Of Care ◽  
Cost Effective ◽  
Transmission Efficiency ◽  
Guided Mode ◽  
Point Of Care Diagnostics ◽  
Identification Approach ◽  
Pharmaceutical Industries ◽  
Guided Mode Resonance ◽  
New Generation

Abstract Raman identification is an instrumental tool with a broad range of applications, yet current spectroscopy approaches fall short in facilitating practical and scalable Raman identification platforms. In this work, we introduce a spectrometerless Raman identification approach that utilizes guided-mode resonance filters. Unlike arrayed narrowband-filters spectrometer, we tailor the transmission characteristics of each filter to match the Raman signature of a given target. Hence, instantaneous Raman identification could be directly achieved at the hardware level with no spectral data post-processing. The filters consist of a metasurface grating encapsulated between two identical distributed Bragg reflectors and are characterized by transmission peaks line-widths narrower than 0.01 nm and transmission efficiency exceeding 98%. We develop a rigorous design methodology to customize the filters’ characteristics such that the maximum optical transmission through a given filter is only attained when exposed to the Raman scattering from its matched target. To illustrate the potential of our approach, we theoretically investigate the identification of four different saccharides as well as the classification of two antibiotic-susceptible and resistant strains of Staphylococcus aureus. We show that our proposed approach can accurately identify these targets. Our work lays the foundation for a new-generation of scalable, compact, and cost-effective instant Raman identification platforms that can be adopted in countless applications from wearables and point-of-care diagnostics to in-line quality control in food and pharmaceutical industries.

scholarly journals Rapid and Highly Sensitive Detection of C-Reaction Protein Using Robust Self-Compensated Guided-Mode Resonance BioSensing System for Point-Of-Care Applications

Biosensors ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 523
Author(s):  
Chu-Tung Yeh ◽  
Devesh Barshilia ◽  
Chia-Jui Hsieh ◽  
Hsun-Yuan Li ◽  
Wen-Hsin Hsieh ◽  
...  
Keyword(s):  
Light Source ◽  
Transverse Electric ◽  
Point Of Care ◽  
Low Cost ◽  
Polarized Light ◽  
Transverse Magnetic ◽  
Sensitive Detection ◽  
Guided Mode ◽  
Guided Mode Resonance ◽  
Biosensing System

The rapid and sensitive detection of human C-reactive protein (CRP) in a point-of-care (POC) may be conducive to the early diagnosis of various diseases. Biosensors have emerged as a new technology for rapid and accurate detection of CRP for POC applications. Here, we propose a rapid and highly stable guided-mode resonance (GMR) optofluidic biosensing system based on intensity detection with self-compensation, which substantially reduces the instability caused by environmental factors for a long detection time. In addition, a low-cost LED serving as the light source and a photodetector are used for intensity detection and real-time biosensing, and the system compactness facilitates POC applications. Self-compensation relies on a polarizing beam splitter to separate the transverse-magnetic-polarized light and transverse-electric-polarized light from the light source. The transverse-electric-polarized light is used as a background signal for compensating noise, while the transverse-magnetic-polarized light is used as the light source for the GMR biosensor. After compensation, noise is drastically reduced, and both the stability and performance of the system are enhanced over a long period. Refractive index experiments revealed a resolution improvement by 181% when using the proposed system with compensation. In addition, the system was successfully applied to CRP detection, and an outstanding limit of detection of 1.95 × 10−8 g/mL was achieved, validating the proposed measurement system for biochemical reaction detection. The proposed GMR biosensing sensing system can provide a low-cost, compact, rapid, sensitive, and highly stable solution for a variety of point-of-care applications.

scholarly journals Comparison of the Optical Planar Waveguide Sensors’ Characteristics Based on Guided-Mode Resonance

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1315
Author(s):  
S. Bellucci ◽  
V. Fitio ◽  
I. Yaremchuk ◽  
O. Vernyhor ◽  
A. Bendziak ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Resonance Curve ◽  
Spectral Width ◽  
Dielectric Substrate ◽  
Angular Width ◽  
Guided Mode ◽  
Metal Grating ◽  
Dielectric Grating ◽  
Guided Mode Resonance ◽  
Angular Reflectance

A comparison of optical sensors’ characteristics based on guided-mode resonance has been carried out. It was considered a prism structure with a metal film, a metal grating on a metal substrate and a dielectric grating on a dielectric substrate. It is shown that the main characteristics are determined by the sensitivity of the constant propagation of the respective waveguides on a change in wavelength and a change in the refractive index of the tested medium. In addition, they depend on the full width at half maximum of the spectral or angular reflectance dependence. The corresponding analytical relationships obtained for the three types of sensors are almost the same. It is demonstrated that the ratio of the sensor spectral sensitivity on the resonance curve spectral width is equal to the ratio of the angular sensitivity on the angular width of the corresponding resonance curve for all three types of sensors.

scholarly journals Imprinted Polymer-Based Guided Mode Resonance Grating Strain Sensors

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3221 ◽  
Author(s):  
Marie-Aline Mattelin ◽  
Jeroen Missinne ◽  
Bert De Coensel ◽  
Geert Van Steenberge
Keyword(s):  
Optical Sensors ◽  
Effective Strain ◽  
Cost Effective ◽  
Strain Sensors ◽  
Strain Sensitivity ◽  
Strain Sensing ◽  
Guided Mode ◽  
Guided Mode Resonance ◽  
Working Distance ◽  
Gmr Sensor

Optical sensors based on guided mode resonance (GMR) realized in polymers are promising candidates for sensitive and cost effective strain sensors. The benefit of GMR grating sensors is the non-contact, easy optical read-out with large working distance, avoiding costly alignment and packaging procedures. The GMR gratings with resonance around 850–900 nm are fabricated using electron beam lithography and replicated using a soft stamp based imprinting technique on 175 μ m-thick foils to make them suitable for optical strain sensing. For the strain measurements, foils are realized with both GMR gratings and waveguides with Bragg gratings. The latter are used as reference sensors and allow extracting the absolute strain sensitivity of the GMR sensor foils. Following this method, it is shown that GMR gratings have an absolute strain sensitivity of 1.02 ± 0.05 pm / μ ε at 870 nm.

Ferromagnetic Resonance Biosensor for Homogeneous and Volumetric Detection of DNA

2017 ◽  
Author(s):  
Bo Tian ◽  
Peter Svedlindh ◽  
Mattias Strömberg ◽  
Erik Wetterskog
Keyword(s):  
Magnetic Nanoparticles ◽  
Ferromagnetic Resonance ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Rolling Circle Amplification ◽  
Resonance Field ◽  
Isothermal Amplification ◽  
Detection Sensitivity ◽  
Serum Samples ◽  
Rolling Circle

In this work, we demonstrate for the first time, a ferromagnetic resonance (FMR) based homogeneous and volumetric biosensor for magnetic label detection. Two different isothermal amplification methods, <i>i.e.</i>, rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) are adopted and combined with a standard electron paramagnetic resonance (EPR) spectrometer for FMR biosensing. For RCA-based FMR biosensor, binding of RCA products of a synthetic Vibrio cholerae target DNA sequence gives rise to the formation of aggregates of magnetic nanoparticles. Immobilization of nanoparticles within the aggregates leads to a decrease of the net anisotropy of the system and a concomitant increase of the resonance field. A limit of detection of 1 pM is obtained with an average coefficient of variation of 0.16%, which is superior to the performance of other reported RCA-based magnetic biosensors. For LAMP-based sensing, a synthetic Zika virus target oligonucleotide is amplified and detected in 20% serum samples. Immobilization of magnetic nanoparticles is induced by their co-precipitation with Mg<sub>2</sub>P<sub>2</sub>O<sub>7</sub> (a by-product of LAMP) and provides a detection sensitivity of 100 aM. The fast measurement, high sensitivity and miniaturization potential of the proposed FMR biosensing technology makes it a promising candidate for designing future point-of-care devices.<br>

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