Novel electrochemiluminescent materials for sensor applications

2014 ◽  
Vol 174 ◽  
pp. 357-367 ◽  
Author(s):  
Lynn Dennany ◽  
Zahera Mohsan ◽  
Alexander L. Kanibolotsky ◽  
Peter J. Skabara
Keyword(s):  
Redox Reactions ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Radical Cations ◽  
Detection Sensitivity ◽  
Sensor Development ◽  
Sensor Applications ◽  
Sensor Devices ◽  
The Impact

Electrochemiluminescence (ECL) uses redox reactions to generate light at an electrode surface, and is gaining increasing attention for biosensor development due to its high sensitivity and excellent signal-to-noise ratio. ECL studies of monodisperse oligofluorene–truxenes (T4 series) have been reported previously, showing the production of stable radical cations and radical anions, generating blue ECL. The compound in this study differs from the original structures, in that there are 2,1,3-benzothiadazole (BT) units inserted between the first and second fluorene units of the quarterfluorenyl arms. It was therefore anticipated that the incorporation of these highly luminescent and ECL-active compounds into sensor development would lead to significant decreases in detection limits. In this contribution, we report on the impact of incorporating these novel complexes into sensor devices on the ECL efficiency, as well as the ability of these to improve the detection sensitivity and decrease the limit of detection using the reagent-free detection of model analytes. The real world impact of these compounds is elucidated through the comparison with more standard ECL materials such as ruthenium-based compounds. The potential for multiple applications is to be examined within this contribution.

scholarly journals Photoacoustic Detection of H2 and NH3 Using Plasmonic Signal Enhancement in GaN Microcantilevers

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 680 ◽  
Author(s):  
Digangana Khan ◽  
Hongmei Li ◽  
Ferhat Bayram ◽  
Durga Gajula ◽  
Goutam Koley
Keyword(s):  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Detection Sensitivity ◽  
Selective Detection ◽  
Signal To Noise ◽  
Photoacoustic Detection ◽  
Laser Illumination ◽  
Pd Nanoparticle ◽  
Sensor Devices ◽  
Reducing Gases

Photoacoustic (PA) detection of H2 and NH3 using plasmonic excitation in Pt- and Pd-decorated GaN piezotransistive microcantilevers were investigated using pulsed 520-nm laser illumination. The sensing performances of 1-nm Pt and Pd nanoparticle (NP) deposited cantilever devices were compared, of which the Pd-coated sensor devices exhibited consistently better sensing performance, with lower limit of detection and superior signal-to-noise ratio (SNR) values, compared to the Pt-coated devices. Among the two functionalization layers, Pd-coated devices were found to respond only to H2 exposure and not to NH3, while Pt-coated devices exhibited repeatable response to both H2 and NH3 exposures, highlighting the potential of the former in performing selective detection between these reducing gases. Optimization of the device-biasing conditions were found to enhance the detection sensitivity of the sensors.

Far-ultraviolet Ionospheric Photometer

2020 ◽  
Author(s):  
Ruyi Peng ◽  
Liping Fu
Keyword(s):  
High Sensitivity ◽  
Detection Sensitivity ◽  
Space Environment ◽  
Physical Parameters ◽  
Optical Remote Sensing ◽  
Electronic Density ◽  
Radio Communications ◽  
Important Means ◽  
Far Ultraviolet ◽  
The Impact

<p>As a space-based optical remote sensing method, Far-ultraviolet Ionospheric Photometer with small size, low power consumption, high sensitivity is an important means to detect physical parameters of the ionosphere. Using the Far-ultraviolet Ionospheric Photometer to detect the intensity of ionospheric 135.6nm night airglow can obtain the ionospheric TEC, F2 layer peak electronic density(NmF2), which can be used to study the information on changes in ionospheric space environment,and the impact of the ionosphere on the radio communications, etc.; The ionospheric 135.6nm day airglow and the LBH radiation radiance can be used to obtain the ionospheric O / N2 ratio information, which can be used to study the space weather events and monitor the electromagnetic environment changes in the Earth's space. The FY3-D Ionospheric Photometer(IPM), launched on November 15, 2017, has a detection sensitivity which is greater than 150 counts / s / Rayleigh and a spatial field of view of 1.6 × 3.5 ° with high horizontal spatial resolution that will help to achieve the fine detection of the ionosphere. This report will analyze the FY3-D IPM detection results.At the same time,the report will introduce our research team’s work on the development and application of other payloads in the far ultraviolet band</p>

scholarly journals An Immunosensor for the Detection of ULBP2 Biomarker

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 568
Author(s):  
Wen-Chi Yang ◽  
Su-Yu Liao ◽  
Thien Luan Phan ◽  
Nguyen Van Hieu ◽  
Pei-Yi Chu ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Impedance Spectrum ◽  
Array Configuration ◽  
Long Term Storage ◽  
Coefficients Of Variation ◽  
Screen Printed Carbon Electrode ◽  
Good Repeatability

Pancreatic cancer (PC) is a global health problem that features a very high mortality rate. The UL16 binding protein 2 (ULBP2) is a new biomarker for PC detection. This study develops a simple, reliable, and inexpensive immunosensor for the detection of the ULBP2 antigen while also investigating the effects of an array configuration of connected sensors and zinc oxide (ZnO) nanoparticles on the immunosensor’s sensitivity. The ULBP2 antibody was immobilized onto the screen-printed carbon electrode (SPCE) surfaces of three different sensors: a simple SPCE (ULBP2-SPCE); an SPCE array, which is a series of identical SPCE connected to each other at different arrangements of rows and columns (ULBP2-SPCE-1x2 and ULBP2-SPCE-1x3); and an SPCE combined with ZnO nanoparticles (ULBP2-ZnO/SPCE). Impedance spectrum measurements for the immunosensors to ULBP2 antigen were conducted and compared. According to the result, the array configurations (ULBP2-SPCE-1x2 and ULBP2-SPCE-1x3) show an improvement of sensitivity compared to the ULBP2-SPCE alone, but the improvement is not as significant as that of the ULBP2-ZnO/SPCE configuration (ULBP2-ZnO/SPCE > ULBP2-SPCE: 18 times larger). The ULBP2-ZnO/SPCE immunosensor has a low limit of detection (1 pg/mL) and a high sensitivity (332.2 Ω/Log(pg/mL)), excellent linearity (R2 = 0.98), good repeatability (coefficients of variation = 5.03%), and is stable in long-term storage (retaining 95% activity after 28 days storage). In an array configuration, the immunosensor has an increased signal-to-noise ratio (ULBP2-SPCE-1x3 > ULBP2-SPCE: 1.5-fold) and sensitivity (ULBP2-SPCE-1x3 > ULBP2-SPCE: 2.6-fold). In conclusion, either the modification with ZnO nanoparticles onto the sensor or the use of an array configuration of sensors can enhance the immunosensor’s sensitivity. In this study, the best immunosensor for detecting ULBP2 antigens is the ULBP2-ZnO/SPCE immunosensor.

Development of an Indirect Competitive Enzyme-Linked Immunosorbent Assay Based on the Multiepitope Peptide for the Synchronous Detection of Staphylococcal Enterotoxin A and G Proteins in Milk

2015 ◽  
Vol 78 (2) ◽  
pp. 362-369 ◽  
Author(s):  
MINGYAN LIANG ◽  
TINGTING ZHANG ◽  
XUELAN LIU ◽  
YANAN FAN ◽  
SHENGLIN XIA ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Food Poisoning ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Synchronous Detection ◽  
Standard Curve ◽  
Stability And Accuracy

Staphylococcal food poisoning (SFP), one of the most common foodborne diseases, results from ingestion of staphylococcal enterotoxins (SEs) in foods. In our previous studies, we found that SEA and SEG were two predominant SE proteins produced by milk-acquired S. aureus isolates. Here, a tandemly arranged multiepitope peptide (named SEAGepis) was designed with six linear B-cell epitopes derived from SEA or SEG and was heterologously expressed. The SEAGepis-specific antibody was prepared by immunizing rabbit with rSEAGepis. Then, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on rSEAGepis and the corresponding antibody was developed to simultaneously detect SEA and SEG. Under the optimized conditions, the ic-ELISA standard curve for rSEAGepis was constructed in the concentration range of 0.5 to 512 ng/ml, and the average coefficients of variation of intra-and interassay were 4.28 and 5.61% during six standard concentrations. The average half-maximal inhibitory concentration was 5.07 ng/ml, and the limit of detection at a signal-to-noise ratio of 3 was 0.52 ng/ml. The anti-rSEAGepis antibody displayed over 90% cross-reactivity with SEA and SEG but less than 0.5% cross-reactivity with other enterotoxins. Artificially contaminated milk with different concentrations of rSEAGepis, SEA, and SEG was detected by the established ic-ELISA; the recoveries of rSEAGepis, SEA, and SEG were 91.1 to 157.5%, 90.3 to 134.5%, and 89.1 to 117.5%, respectively, with a coefficient of variation below 12%. These results demonstrated that the newly established ic-ELISA possessed high sensitivity, specificity, stability, and accuracy and could potentially be a useful analytical method for synchronous detection of SEA and SEG in milk.

scholarly journals An ultra-low noise capacitance to voltage converter for sensor applications in 0.35  µm CMOS

2017 ◽  
Vol 6 (2) ◽  
pp. 285-301 ◽  
Author(s):  
Alexander Utz ◽  
Christian Walk ◽  
Norbert Haas ◽  
Tatjana Fedtschenko ◽  
Alexander Stanitzki ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Signal To Noise Ratio ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Micro Electro Mechanical System ◽  
Low Noise ◽  
Capacitive Pressure Sensor ◽  
Sensor Applications ◽  
Wide Range ◽  
Ultra Low Noise

Abstract. In this paper we present a readout circuit for capacitive micro-electro-mechanical system (MEMS) sensors such as accelerometers, gyroscopes or pressure sensors. A flexible interface allows connection of a wide range of types of sensing elements. The ASIC (application-specific integrated circuit) was designed with a focus on ultra-low noise operation and high analog measurement performance. Theoretical considerations on system noise are presented which lead to design requirements affecting the reachable overall measurement performance. Special emphasis is put on the design of the fully differential operational amplifiers, as these have the dominant influence on the achievable overall performance. The measured input referred noise is below 50 zF/Hz within a bandwidth of 10 Hz to 10 kHz. Four adjustable gain settings allow the adaption to measurement ranges from ±750 fF to ±3 pF. This ensures compatibility with a wide range of sensor applications. The full input signal bandwidth ranges from 0 Hz to more than 50 kHz. A high-precision accelerometer system was built from the described ASIC and a high-sensitivity, low-noise sensor MEMS. The design of the MEMS is outlined and the overall system performance, which yields a combined noise floor of 200 ng/Hz, is demonstrated. Finally, we show an application using the ASIC together with a CMOS integrated capacitive pressure sensor, which yields a measurement signal-to-noise ratio (SNR) of more than 100 dB.

Methods for enhancement of high-sensitivity detection for a surface wave EMAT

2021 ◽  
pp. 1-23
Author(s):  
Jin Zhang ◽  
Xin Wang ◽  
Xuebing Wang ◽  
LingLing Zheng ◽  
Ruipeng Li ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Pulse Compression ◽  
Signal To Noise Ratio ◽  
Single Layer ◽  
High Sensitivity ◽  
Element Model ◽  
Industrial Applications ◽  
Detection Sensitivity ◽  
Electromagnetic Acoustic Transducer ◽  
Compression Technique

Due to the poor conversion efficiency and signal-to-noise ratio (SNR) of Electromagnetic Acoustic Transducer (EMAT) testing, the defect detection sensitivity is limited, which restricts the extensive industrial applications. A finite element model for the testing process of a meander-coil EMAT was established that considers the simplified excitation and detection circuits for the EMAT. Based on this model, the effect of the connection methods (parallel or series) of the coils in the generating and receiving EMATs on their generating and receiving efficiency was investigated, and the simulation results were validated experimentally. Subsequently, the pulse compression technique with a 13-bit Barker code was used for the EMAT detection, and improvements of the SNR and range resolution were established through numerical simulation and experimental measurement. The results show that compared with the traditional EMAT design, which comprises single-layer transmitting and receiving coils, the conversion efficiency of the optimized EMAT with two excitation and receiving coils in the parallel connection can be improved by 52.8%. With the application of the Barker-coded pulse compression to detect the ultrasonic A-scan signal with no synchronous average, the SNR of the defect echo can be improved by 9.5 dB compared with the A-scan signal with 128 synchronous averages.

A Design of Multi-Band UHF Sensor for Partial Discharge Detection

2013 ◽  
Vol 394 ◽  
pp. 435-440 ◽  
Author(s):  
Bin Liu ◽  
Jing De An ◽  
Wei Dong Zhang ◽  
You Lin Xu
Keyword(s):  
Signal To Noise Ratio ◽  
Partial Discharge ◽  
High Sensitivity ◽  
Ultra Wideband ◽  
Detection Sensitivity ◽  
Surface Discharge ◽  
Communication Signals ◽  
Metallic Particles ◽  
Selection Of ◽  
Multi Band

The selection and design of the sensor is one of the key technologies for UHF PD detection. The UHF sensors popular used in PD detection and location in substation are partial discharge UHF sensor are usually ultra wideband antenna in the frequency range of 200 MHz to 1.5 GHz, which contains interference from communication signals. Accordingly, in order to improve the detection sensitivity and the signal-to-noise ratio, a kind of multi-band UHF narrowband sensor is proposed and designed in accordance with the principles of the loop antenna for PD detection. The proposed frequency resonant bands are set in the ranges of 480MHz-520MHz, 800MHz-850MHz and 1.1GHz-1.2GHz. The design based on simulation is finished and the performances of the prototype sensor are researched by parametric test and PD detection of three typical discharges: corona discharge, surface discharge and metallic particles discharge generated by PD mode. Results show that the selection of band for the UHF sensor is reasonable, and the sensor is with high sensitivity.

scholarly journals Sensing Techniques for Organochlorides through Intermolecular Interaction with Bicyclic Amidines

Biosensors ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 413
Author(s):  
Jong-Won Park ◽  
Lee-Woon Jang ◽  
Erik C. Jensen ◽  
Amanda Stockton ◽  
Jungkyu Kim
Keyword(s):  
Environmental Protection Agency ◽  
Limit Of Detection ◽  
Direct Detection ◽  
Colorimetric Assay ◽  
High Sensitivity ◽  
The United States ◽  
Detection Sensitivity ◽  
Detection Mechanism ◽  
Sensing Platform ◽  
High Volatility

Toxic organochloride molecules are widely used in industry for various purposes. With their high volatility, the direct detection of organochlorides in environmental samples is challenging. Here, a new organochloride detection mechanism using 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) is introduced to simplify a sensing method with higher detection sensitivity. Three types of organochloride compounds-trichloroethylene (TCE), dichloromethane (DCM), and dichlorodiphenyltrichloroethane (DDT)—were targeted to understand DCM conjugation chemistry by using nuclear magnetic resonance (NMR) and liquid chromatography with a mass spectrometer (LC-MS). 13C-NMR spectra and LC-MS data indicated that DBN can be labeled on these organochloride compounds by chlorine–nitrogen interaction. Furthermore, to demonstrate the organochloride sensing capability, the labeling yield and limit of detection were determined by a colorimetric assay as well as micellar electrokinetic chromatography (MEKC). The interaction with DBN was most appreciable for TCE, among other organochlorides. TCE was detected at picomolar levels, which is two orders of magnitude lower than the maximum contaminant level set by the United States Environmental Protection Agency. MEKC, in conjunction with this DBN-labeling method, enables us to develop a field-deployable sensing platform for detecting toxic organochlorides with high sensitivity.

scholarly journals Hydrogel-Based Sensors for Ethanol Detection in Alcoholic Beverages

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1199 ◽  
Author(s):  
Jan Erfkamp ◽  
Margarita Guenther ◽  
Gerald Gerlach
Keyword(s):  
Ph Value ◽  
Limit Of Detection ◽  
Swelling Pressure ◽  
High Sensitivity ◽  
Detection Sensitivity ◽  
Alcoholic Beverages ◽  
Reliable Determination ◽  
Piezoresistive Pressure Sensor ◽  
Alcohol Sensor

A fast and reliable determination of the ethanol concentration is essential in the analysis of alcoholic beverages. However, different factors like pH value or salt concentration can influence the ethanol measurement. Furthermore, analytical figures of merit for the alcohol sensor, such as limit of detection, sensitivity and measurement uncertainty, are necessary for the application. In this paper, a detailed sensor characterization of a novel sensor based on ethanol-sensitive poly acrylamide hydrogels will be presented. The resulting swelling pressure of the hydrogel was transformed via a piezoresistive pressure sensor into a measurable output voltage. These kinds of sensors can be used over a large measuring range, up to 50 vol% ethanol and more, with a high sensitivity. In the range from pH 7.4 to 4, the pH value had no influence on the sensor signal. Higher salt concentrations can slightly influence the measurement. The detection limit amounts to 0.06–0.65 vol% ethanol. The concentration of a vodka sample was determined with a sufficient measuring uncertainty.

scholarly journals Novel Time-Resolved Fluorescence Immunochromatography Paper-Based Sensor with Signal Amplification Strategy for Detection of Deoxynivalenol

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6577
Author(s):  
Haowei Dong ◽  
Xingshuang An ◽  
Yaodong Xiang ◽  
Fukai Guan ◽  
Qi Zhang ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
High Sensitivity ◽  
Detection Sensitivity ◽  
Intensity Change ◽  
Fluorescence Signal ◽  
Time Resolved Fluorescence ◽  
Working Standard ◽  
Time Resolved ◽  
Field Detection ◽  
Antibody Labeling

Immunoassay has the advantages of high sensitivity, high specificity, and simple operation, and has been widely used in the detection of mycotoxins. For several years, time-resolved fluorescence immunochromatography (TRFIA) paper-based sensors have attracted much attention as a simple and low-cost field detection technology. However, a traditional TRFIA paper-based sensor is based on antibody labeling, which cannot easily meet the current detection requirements. A second antibody labeling method was used to amplify the fluorescence signal and improve the detection sensitivity. Polystyrene fluorescent microspheres were combined with sheep anti-mouse IgG to prepare fluorescent probes (Eu-IgGs). After the probe fully reacted with the antibody (Eu-IgGs-Abs) in the sample cell, it was deployed on the paper-based sensor using chromatography. Eu-IgGs-Abs that were not bound to the target were captured on the T-line, while those that were bound were captured on the C-line. The paper-based sensor reflected the corresponding fluorescence intensity change. Because a single molecule of the deoxynivalenol antibody could bind to multiple Eu-IgGs, this method could amplify the fluorescence signal intensity on the unit antibody and improve the detection sensitivity. The working standard curve of the sensor was established under the optimum working conditions. It showed the lower limit of detection and higher recovery rate when it was applied to actual samples and compared with other methods. This sensor has the advantages of high sensitivity, good accuracy, and good specificity, saving the amount of antibody consumed and being suitable for rapid field detection of deoxynivalenol.

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