scholarly journals Integrált optikai szenzor biológiai minták gyors analíziséhez

2015 ◽  
Vol 156 (52) ◽  
pp. 2116-2119
Author(s):  
Anna Mathesz ◽  
Sándor Valkai ◽  
Orsolya Sipos ◽  
Balázs Stercz ◽  
Béla Kocsis ◽  
...  
Keyword(s):  
Medical Diagnostics ◽  
Microfluidic System ◽  
Enzyme Linked Immunosorbent Assay ◽  
Label Free ◽  
Microbial Forensics ◽  
Wide Range ◽  
Label Free Detection ◽  
Integrated Optical ◽  
Measuring Techniques ◽  
Escherichia Coli Bacteria

Introduction: In the medical diagnostics of bacteria, the rapid detection of pathogenic microorganisms from body fluids is one of the most important tasks. The majority of the modern measuring techniques are based on specific labels bound to the bacteria. However, this strategy usually assumes a rather time-consuming procedure involving several steps (e.g., the widely used enzyme-linked immunosorbent assay normally consists of 5 consecutive steps). Hence, there is an urgent need for the elaboration of rapid, “label-free” techniques, that are often based on Lab-on-a-chip devices. Aim: In this paper, the authors report on the development of a biosensor based on a miniature, integrated optical Mach–Zehnder interferometer. Method: Functionalization of the measuring arm of the sensor by antibodies, made the rapid and specific label-free detection of pathogens feasible. Results: Using the combination of the interferometer with a microfluidic system, the device was able to detect Escherichia coli bacteria at concentrations as low as 106 colony forming unit/ml within minutes. Conclusions: This makes the newly developed biosensor a promising device for a wide range of applications, not only in medical microbiology, but microbial forensics, criminal investigations, bio-terrorism threats and in environmental studies as well. Orv. Hetil., 2015, 156(52), 2116–2119.

scholarly journals Integrated optical biosensor for rapid detection of bacteria

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Anna Mathesz ◽  
Sándor Valkai ◽  
Attila Újvárosy ◽  
Badri Aekbote ◽  
Orsolya Sipos ◽  
...  
Keyword(s):  
Rapid Detection ◽  
Pathogenic Bacteria ◽  
Optical Biosensor ◽  
Medical Diagnostics ◽  
Microfluidic System ◽  
Body Fluids ◽  
Label Free ◽  
Label Free Detection ◽  
Integrated Optical ◽  
Escherichia Coli Bacteria

AbstractIn medical diagnostics, rapid detection of pathogenic bacteria from body fluids is one of the basic issues. Most state-of-the-art methods require optical labeling, increasing the complexity, duration and cost of the analysis. Therefore, there is a strong need for developing selective sensory devices based on label-free techniques, in order to increase the speed, and reduce the cost of detection. In a recent paper, we have shown that an integrated optical Mach-Zehnder interferometer, a highly sensitive all-optical device made of a cheap photopolymer, can be used as a powerful lab-on-a-chip tool for specific, labelfree detection of proteins. By proper modifications of this technique, our interferometric biosensor was combined with a microfluidic system allowing the rapid and specific detection of bacteria from solutions, having the surface of the sensor functionalized by bacterium-specific antibodies. The experiments proved that the biosensor was able to detect Escherichia coli bacteria at concentrations of 106 cfu/ml within a few minutes, that makes our device an appropriate tool for fast, label-free detection of bacteria from body fluids such as urine or sputum. On the other hand, possible applications of the device may not be restricted to medical microbiology, since bacterial identification is an important task in microbial forensics, criminal investigations, bio-terrorism threats and in environmental studies, as well.

Fabrication of Precise Asymmetric Nanoshells Array with Nanogaps for a Label-Free Immunoassay Based on NIR-Light Responsive LSPR

2012 ◽  
Vol 523-524 ◽  
pp. 680-685
Author(s):  
Shuhei Uchida ◽  
Kazuya Yamamura ◽  
Nobuyuki Zettsu
Keyword(s):  
Near Infrared ◽  
Atmospheric Pressure Plasma ◽  
High Sensitivity ◽  
Medical Diagnostics ◽  
Localized Surface Plasmon ◽  
Label Free ◽  
Fabrication Technique ◽  
Alternative Structures ◽  
Wide Range ◽  
Surrounding Refractive Index

Localized surface plasmon resonance (LSPR) based sensors are a well established technology utilized for label-free biochemical sensing in immunoassay, medical diagnostics and environmental monitoring. The understanding of asymmetric metal nanoparticles, new object for complex, coupled plasmon systems providing localized significantly enhanced E-field, is central to a wide range of novel applications and processes in science of higher sensitive sensing systems. However, few methods are available for actual characterization of such nanostructures at the single particle level. Here we propose a precise and large sized scale fabrication technique for asymmetric nanoshells array with nanogaps of several tens of nanometers for LSPR sensor through atmospheric pressure plasma etching processes. A nanoshell was simply constructed by laminating thin Au films on periodic isolated polymer nanoparticles template. This nanoshells array was expected to exhibit specific near-infrared plasmonic properties. When measuring the sensitivity, nanoshells array exhibited a high sensitivity to changes of surrounding refractive index and showed a higher sensor figure of merit than the alternative structures. This indicated that the enhanced plasmon E-field in the asymmetric nanostructures improved sensor performance. Our fabrication technique and the optical properties of the arrays will provide useful information for developing new plasmonic applications.

scholarly journals An Overview of High Frequency Acoustic Sensors—QCMs, SAWs and FBARs—Chemical and Biochemical Applications

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4395 ◽  
Author(s):  
Adnan Mujahid ◽  
Adeel Afzal ◽  
Franz L. Dickert
Keyword(s):  
High Frequency ◽  
Piezoelectric Materials ◽  
Fundamental Property ◽  
High Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Label Free ◽  
Detection Mechanism ◽  
Acoustic Transducers ◽  
Resonance Frequencies ◽  
Label Free Detection

Acoustic devices have found wide applications in chemical and biosensing fields owing to their high sensitivity, ruggedness, miniaturized design and integration ability with on-field electronic systems. One of the potential advantages of using these devices are their label-free detection mechanism since mass is the fundamental property of any target analyte which is monitored by these devices. Herein, we provide a concise overview of high frequency acoustic transducers such as quartz crystal microbalance (QCM), surface acoustic wave (SAW) and film bulk acoustic resonators (FBARs) to compare their working principles, resonance frequencies, selection of piezoelectric materials for their fabrication, temperature-frequency dependency and operation in the liquid phase. The selected sensor applications of these high frequency acoustic transducers are discussed primarily focusing on the two main sensing domains, i.e., biosensing for working in liquids and gas/vapor phase sensing. Furthermore, the sensor performance of high frequency acoustic transducers in selected cases is compared with well-established analytical tools such as liquid chromatography mass spectrometry (LC-MS), gas chromatographic (GC) analysis and enzyme-linked immunosorbent assay (ELISA) methods. Finally, a general comparison of these acoustic devices is conducted to discuss their strengths, limitations, and commercial adaptability thus, to select the most suitable transducer for a particular chemical/biochemical sensing domain.

scholarly journals Label-Free Detection of Chondroitin Sulphate Proteoglycan 4 by a Polyaniline/Graphene Nanocomposite Functionalized Impedimetric Immunosensor

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
JingJing Fu ◽  
ZhuanZhuan Shi ◽  
Man Li ◽  
Yangyang Wang ◽  
Ling Yu
Keyword(s):  
Cell Lines ◽  
Chondroitin Sulphate ◽  
Low Cost ◽  
Enzyme Linked Immunosorbent Assay ◽  
Label Free ◽  
Sulphate Proteoglycan ◽  
Chondroitin Sulphate Proteoglycan ◽  
Label Free Detection ◽  
Proteoglycan 4 ◽  
Impedimetric Immunosensor

The chondroitin sulphate proteoglycan 4 (CSPG4), also known as high molecular weight-melanoma associated antigen (HMW-MAA), is a tumor-associated antigen that is expressed in more than 85% of surgically removed melanoma lesions but has restricted distribution in normal tissues. The diagnostic and therapeutic value of CSPG4 drives a need for sensitive and low-cost detection approaches. To this end, we developed a polyaniline/graphene oxide nanocomposite (PANI@GO) that was electrochemically codeposited on indium tin oxide (ITO) electrode. Glutaraldehyde mediated the covalent immobilization of CSPG4 specific antibody mAbD2.8.5 to construct a CSPG4 immunosensor using cell culture media and cell lysate as samples. The fully assembled impedimetric immunosensor was used to detect CSPG4 in CSPG4-positive cell lines M14/CSPG4 and MV3. No impedance signal changes could be observed from CSPG4-negative cell lines M14 and mAbMk2-23 showing the specificity of the CSPG4-impedimetric immunosensor. This low-cost, simple, and label-free analytical method is an alternative to enzyme-linked immunosorbent assay and flow cytometry in screening of CSPG4 in complex biological samples.

scholarly journals Topological insulator overlayer to enhance the sensitivity and detection limit of surface plasmon resonance sensor

Nanophotonics ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1941-1951
Author(s):  
Jiaqi Zhu ◽  
Yuxuan Ke ◽  
Jianfeng Dai ◽  
Qi You ◽  
Leiming Wu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Label Free ◽  
Spr Sensor ◽  
Wide Range ◽  
Resonance Sensor ◽  
Label Free Detection ◽  
Potential Applications

AbstractSurface plasmon resonance (SPR) sensors have been applied in a wide range of applications for real-time and label-free detection. In this article, by covering the topological insulators nanosheets on the surface of the noble metal (Au), the sensitivity of the SPR sensor is greatly enhanced because of the strong interaction of light with Au–bismuth selenide (Bi2Se3) heterostructure. It is shown that the sensitivity of proposed SPR sensors depends on the concentration of Bi2Se3 solution or the thickness of the coated Bi2Se3 film. The optimised sensitivity (2929.1 nm/RIU) and figure of merit (33.45 RIU−1) have been obtained after three times drop-casting, and the enhancement sensitivity of proposed sensors is up to 51.97% compared to the traditional Au–SPR sensors. Meanwhile, the reflection spectrum is simulated by using the method of effective refractive index, and the reason for the increase of sensitivity is analysed theoretically. For researching the application of modified SPR sensor, heavy metal detection is employed to detect in the last part. Our proposed SPR sensors have potential applications in heavy metal detections and biosensing.

scholarly journals Label-Free Optical Resonator-Based Biosensors

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5901
Author(s):  
Donggee Rho ◽  
Caitlyn Breaux ◽  
Seunghyun Kim
Keyword(s):  
Point Of Care ◽  
Health And Safety ◽  
Disease Diagnosis ◽  
Medical Diagnostics ◽  
Sample Volume ◽  
Small Sample ◽  
Optical Resonator ◽  
Future Research ◽  
Label Free ◽  
Label Free Detection

The demand for biosensor technology has grown drastically over the last few decades, mainly in disease diagnosis, drug development, and environmental health and safety. Optical resonator-based biosensors have been widely exploited to achieve highly sensitive, rapid, and label-free detection of biological analytes. The advancements in microfluidic and micro/nanofabrication technologies allow them to be miniaturized and simultaneously detect various analytes in a small sample volume. By virtue of these advantages and advancements, the optical resonator-based biosensor is considered a promising platform not only for general medical diagnostics but also for point-of-care applications. This review aims to provide an overview of recent progresses in label-free optical resonator-based biosensors published mostly over the last 5 years. We categorized them into Fabry-Perot interferometer-based and whispering gallery mode-based biosensors. The principles behind each biosensor are concisely introduced, and recent progresses in configurations, materials, test setup, and light confinement methods are described. Finally, the current challenges and future research topics of the optical resonator-based biosensor are discussed.

scholarly journals Study of the Fabrication Technology of Hybrid Microfluidic Biochips for Label-Free Detection of Proteins

Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 20
Author(s):  
Nikita Sitkov ◽  
Tatiana Zimina ◽  
Alexey Kolobov ◽  
Evgeny Sevostyanov ◽  
Valentina Trushlyakova ◽  
...  
Keyword(s):  
Technological Process ◽  
Biological Fluid ◽  
Protein Structures ◽  
Microfluidic System ◽  
Diagnostic Tools ◽  
Fluorometric Detection ◽  
Label Free ◽  
Protein Markers ◽  
Label Free Detection ◽  
Microfluidic Biochips

A study of the peculiarities and a comparative analysis of the technologies used for the fabrication of elements of novel hybrid microfluidic biochips for express biomedical analysis have been carried out. The biochips were designed with an incorporated microfluidic system, which enabled an accumulation of the target compounds in a biological fluid to be achieved, thus increasing the biochip system’s sensitivity and even implementing a label-free design of the detection unit. The multilevel process of manufacturing a microfluidic system of a given topology for label-free fluorometric detection of protein structures is presented. The technological process included the chemical modification of the working surface of glass substrates by silanization using (3-aminopropyl) trimethoxysilane (APTMS), formation of the microchannels, for which SU-8 technologies and a last generation dry film photoresist were studied and compared. The solid-state phosphor layers were deposited using three methods: drop application; airbrushing; and mechanical spraying onto the adhesive surface. The processes of sealing the system, installing input ports, and packaging using micro-assembly technologies are described. The technological process has been optimized and the biochip was implemented and tested. The presented system can be used to design novel high-performance diagnostic tools that implement the function of express detection of protein markers of diseases and create low-power multimodal, highly intelligent portable analytical decision-making systems in medicine.

scholarly journals Detection of Escherichia coli bacteria by impact electrochemistry

The Analyst ◽  
2018 ◽  
Vol 143 (20) ◽  
pp. 4840-4843 ◽  
Author(s):  
Rosa A. S. Couto ◽  
Lifu Chen ◽  
Sabine Kuss ◽  
Richard G. Compton
Keyword(s):  
Escherichia Coli ◽  
Label Free ◽  
Redox Species ◽  
E Coli ◽  
Label Free Detection ◽  
Escherichia Coli Bacteria ◽  
First Time ◽  
Phenylene Diamine

Employing the redox species N,N,N′,N′-tetramethyl-para-phenylene-diamine (TMPD), the label-free detection of E. coli, based on an electrochemical “on”-signal during impact electrochemistry, is reported for the first time.

scholarly journals Predicting Future Prospects of Aptamers in Field-Effect Transistor Biosensors

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 680 ◽  
Author(s):  
Cao-An Vu ◽  
Wen-Yih Chen
Keyword(s):  
Small Molecules ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Field Effect Transistors ◽  
High Specificity ◽  
Label Free ◽  
Sensing Technology ◽  
Wide Range ◽  
Label Free Detection ◽  
Effect Transistor

Aptamers, in sensing technology, are famous for their role as receptors in versatile applications due to their high specificity and selectivity to a wide range of targets including proteins, small molecules, oligonucleotides, metal ions, viruses, and cells. The outburst of field-effect transistors provides a label-free detection and ultra-sensitive technique with significantly improved results in terms of detection of substances. However, their combination in this field is challenged by several factors. Recent advances in the discovery of aptamers and studies of Field-Effect Transistor (FET) aptasensors overcome these limitations and potentially expand the dominance of aptamers in the biosensor market.

scholarly journals Detection of Myoglobin with an Open-Cavity-Based Label-Free Photonic Crystal Biosensor

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Bailin Zhang ◽  
Juan Manuel Tamez-Vela ◽  
Steven Solis ◽  
Gilbert Bustamante ◽  
Ralph Peterson ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Point Of Care ◽  
Microfluidic System ◽  
Cardiac Biomarkers ◽  
Detection Sensitivity ◽  
Label Free ◽  
Binding Assays ◽  
Biochemical Modification ◽  
Label Free Detection ◽  
Biomolecular Assays

The label-free detection of one of the cardiac biomarkers, myoglobin, using a photonic-crystal-based biosensor in a total-internal-reflection configuration (PC-TIR) is presented in this paper. The PC-TIR sensor possesses a unique open optical microcavity that allows for several key advantages in biomolecular assays. In contrast to a conventional closed microcavity, the open configuration allows easy functionalization of the sensing surface for rapid biomolecular binding assays. Moreover, the properties of PC structures make it easy to be designed and engineered for operating at any optical wavelength. Through fine design of the photonic crystal structure, biochemical modification of the sensor surface, and integration with a microfluidic system, we have demonstrated that the detection sensitivity of the sensor for myoglobin has reached the clinically significant concentration range, enabling potential usage of this biosensor for diagnosis of acute myocardial infarction. The real-time response of the sensor to the myoglobin binding may potentially provide point-of-care monitoring of patients and treatment effects.

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