Editorial

3 pages, 168 KiB

Open AccessEditorial

A Label-Free and Affordable Solution to Point-of-Care Testing Devices

by Mon-Juan Lee

Biosensors 2022, 12(4), 192; https://0-doi-org.brum.beds.ac.uk/10.3390/bios12040192 - 24 Mar 2022

Viewed by 1416

Clinical diagnosis and disease monitoring often require the detection of small-molecule analytes and disease-related proteins in body fluids [...] Full article

(This article belongs to the Special Issue Electrical and Electro-Optical Biosensors)

Research

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12 pages, 1660 KiB

Open AccessArticle

Dielectrophoretic and Electrical Impedance Differentiation of Cancerous Cells Based on Biophysical Phenotype

by Ina Turcan, Iuliana Caras, Thomas Gabriel Schreiner, Catalin Tucureanu, Aurora Salageanu, Valentin Vasile, Marioara Avram, Bianca Tincu and Marius Andrei Olariu

Biosensors 2021, 11(10), 401; https://0-doi-org.brum.beds.ac.uk/10.3390/bios11100401 - 17 Oct 2021

Cited by 12 | Viewed by 2427

Abstract

Here, we reported a study on the detection and electrical characterization of both cancer cell line and primary tumor cells. Dielectrophoresis (DEP) and electrical impedance spectroscopy (EIS) were jointly employed to enable the rapid and label-free differentiation of various cancer cells from normal [...] Read more.

Here, we reported a study on the detection and electrical characterization of both cancer cell line and primary tumor cells. Dielectrophoresis (DEP) and electrical impedance spectroscopy (EIS) were jointly employed to enable the rapid and label-free differentiation of various cancer cells from normal ones. The primary tumor cells that were collected from two colorectal cancer patients, cancer cell lines (SW-403, Jurkat, and THP-1), and healthy peripheral blood mononuclear cells (PBMCs) were trapped first at the level of interdigitated microelectrodes with the help of dielectrophoresis. Correlation of the cells dielectric characteristics that was obtained via electrical impedance spectroscopy (EIS) allowed evident differentiation of the various types of cell. The differentiations were assigned to a “dielectric phenotype” based on their crossover frequencies. Finally, Randles equivalent circuit model was employed for highlighting the differences with regard to a series group of charge transport resistance and constant phase element for cancerous and normal cells. Full article

(This article belongs to the Special Issue Electrical and Electro-Optical Biosensors)

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13 pages, 2448 KiB

Open AccessArticle

Design and Analysis of a Single System of Impedimetric Biosensors for the Detection of Mosquito-Borne Viruses

by Fahmida Nasrin, Kenta Tsuruga, Doddy Irawan Setyo Utomo, Ankan Dutta Chowdhury and Enoch Y. Park

Biosensors 2021, 11(10), 376; https://0-doi-org.brum.beds.ac.uk/10.3390/bios11100376 - 07 Oct 2021

Cited by 8 | Viewed by 2396

Abstract

The treatment for mosquito-borne viral diseases such as dengue virus (DENV), zika virus (ZIKV), and chikungunya virus (CHIKV) has become difficult due to delayed diagnosis processes. In addition, sharing the same transmission media and similar symptoms at the early stage of infection of [...] Read more.

The treatment for mosquito-borne viral diseases such as dengue virus (DENV), zika virus (ZIKV), and chikungunya virus (CHIKV) has become difficult due to delayed diagnosis processes. In addition, sharing the same transmission media and similar symptoms at the early stage of infection of these diseases has become more critical for early diagnosis. To overcome this, a common platform that can identify the virus with high sensitivity and selectivity, even for the different serotypes, is in high demand. In this study, we have attempted an electrochemical impedimetric method to detect the ZIKV, DENV, and CHIKV using their corresponding antibody-conjugated sensor electrodes. The significance of this method is emphasized on the fabrication of a common matrix of gold–polyaniline and sulfur, nitrogen-doped graphene quantum dot nanocomposites (Au-PAni-N,S-GQDs), which have a strong impedimetric response based only on the conjugated antibody, resulting in minimum cross-reactivity for the detection of various mosquito-borne viruses, separately. As a result, four serotypes of DENV and ZIKV, and CHIKV have been detected successfully with an LOD of femtogram mL⁻¹. Full article

(This article belongs to the Special Issue Electrical and Electro-Optical Biosensors)

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14 pages, 3441 KiB

Open AccessArticle

A Single-Substrate Biosensor with Spin-Coated Liquid Crystal Film for Simple, Sensitive and Label-Free Protein Detection

by Po-Chang Wu, Chao-Ping Pai, Mon-Juan Lee and Wei Lee

Biosensors 2021, 11(10), 374; https://0-doi-org.brum.beds.ac.uk/10.3390/bios11100374 - 06 Oct 2021

Cited by 4 | Viewed by 2075

Abstract

A liquid crystal (LC)-based single-substrate biosensor was developed by spin-coating an LC thin film on a dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP)-decorated glass slide. Compared with the conventional sandwiched cell configuration, the simplified procedure for the preparation of an LC film allows the film thickness to [...] Read more.

A liquid crystal (LC)-based single-substrate biosensor was developed by spin-coating an LC thin film on a dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP)-decorated glass slide. Compared with the conventional sandwiched cell configuration, the simplified procedure for the preparation of an LC film allows the film thickness to be precisely controlled by adjusting the spin rate, thus eliminating personal errors involved in LC cell assembly. The limit of detection (LOD) for bovine serum albumin (BSA) was lowered from 10⁻⁵ g/mL with a 4.2-μm-thick sandwiched cell of the commercial LC E7 to 10⁻⁷ g/mL with a 4.2-μm-thick spin-coated E7 film and further to 10⁻⁸ g/mL by reducing the E7 film thickness to 3.4 μm. Moreover, by exploiting the LC film of the highly birefringent nematic LC HDN in the immunodetection of the cancer biomarker CA125, an LOD comparable to that determined with a sandwiched HDN cell was achieved at 10⁻⁸ g/mL CA125 using a capture antibody concentration an order of magnitude lower than that in the LC cell. Our results suggest that employing spin-coated LC film instead of conventional sandwiched LC cell provides a more reliable, reproducible, and cost-effective single-substrate platform, allowing simple fabrication of an LC-based biosensor for sensitive and label-free protein detection and immunoassay. Full article

(This article belongs to the Special Issue Electrical and Electro-Optical Biosensors)

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14 pages, 4558 KiB

Open AccessArticle

Millimeter-Wave-Based Spoof Localized Surface Plasmonic Resonator for Sensing Glucose Concentration

by Yelim Kim, Ahmed Salim and Sungjoon Lim

Biosensors 2021, 11(10), 358; https://0-doi-org.brum.beds.ac.uk/10.3390/bios11100358 - 28 Sep 2021

Cited by 11 | Viewed by 2413

Abstract

Glucose-monitoring sensors are necessary and have been extensively studied to prevent and control health problems caused by diabetes. Spoof localized surface plasmon (LSP) resonance sensors have been investigated for chemical sensing and biosensing. A spoof LSP has similar characteristics to an LSP in [...] Read more.

Glucose-monitoring sensors are necessary and have been extensively studied to prevent and control health problems caused by diabetes. Spoof localized surface plasmon (LSP) resonance sensors have been investigated for chemical sensing and biosensing. A spoof LSP has similar characteristics to an LSP in the microwave or terahertz frequency range but with certain advantages, such as a high-quality factor and improved sensitivity. In general, microwave spoof LSP resonator-based glucose sensors have been studied. In this study, a millimeter-wave-based spoof surface plasmonic resonator sensor is designed to measure glucose concentrations. The millimeter-wave-based sensor has a smaller chip size and higher sensitivity than microwave-frequency sensors. Therefore, the microfluidic channel was designed to be reusable and able to operate with a small sample volume. For alignment, a polydimethylsiloxane channel was simultaneously fabricated using a multilayer bonding film to attach the upper side of the pattern, which is concentrated in the electromagnetic field. This real-time sensor detects the glucose concentration via changes in the S11 parameter and operates at 28 GHz with an average sensitivity of 0.015669 dB/(mg/dL) within the 0–300 mg/dL range. The minimum detectable concentration and the distinguishable signal are 1 mg/dL and 0.015669 dB, respectively, from a 3.4 μL sample. The reusability and reproducibility were assessed through replicates. Full article

(This article belongs to the Special Issue Electrical and Electro-Optical Biosensors)

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15 pages, 40335 KiB

Open AccessArticle

Label-Free Detection and Spectrometrically Quantitative Analysis of the Cancer Biomarker CA125 Based on Lyotropic Chromonic Liquid Crystal

by Hassanein Shaban, Mon-Juan Lee and Wei Lee

Biosensors 2021, 11(8), 271; https://0-doi-org.brum.beds.ac.uk/10.3390/bios11080271 - 11 Aug 2021

Cited by 7 | Viewed by 2678

Abstract

Compared with thermotropic liquid crystals (LCs), the biosensing potential of lyotropic chromonic liquid crystals (LCLCs), which are more biocompatible because of their hydrophilic nature, has scarcely been investigated. In this study, the nematic phase, a mesophase shared by both thermotropic LCs and LCLCs, [...] Read more.

Compared with thermotropic liquid crystals (LCs), the biosensing potential of lyotropic chromonic liquid crystals (LCLCs), which are more biocompatible because of their hydrophilic nature, has scarcely been investigated. In this study, the nematic phase, a mesophase shared by both thermotropic LCs and LCLCs, of disodium cromoglycate (DSCG) was employed as the sensing mesogen in the LCLC-based biosensor. The biosensing platform was constructed so that the LCLC was homogeneously aligned by the planar anchoring strength of polyimide, but was disrupted in the presence of proteins such as bovine serum albumin (BSA) or the cancer biomarker CA125 captured by the anti-CA125 antibody, with the level of disturbance (and the optical signal thus produced) predominated by the amount of the analyte. The concentration- and wavelength-dependent optical response was analyzed by transmission spectrometry in the visible light spectrum with parallel or crossed polarizers. The concentration of CA125 can be quantified with spectrometrically derived parameters in a linear calibration curve. The limit of detection for both BSA and CA125 of the LCLC-based biosensor was superior or comparable to that of thermotropic LC-based biosensing techniques. Our results provide, to the best of our knowledge, the first evidence that LCLCs can be applied in spectrometrically quantitative biosensing. Full article

(This article belongs to the Special Issue Electrical and Electro-Optical Biosensors)

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15 pages, 3809 KiB

Open AccessArticle

Signal Amplification in an Optical and Dielectric Biosensor Employing Liquid Crystal-Photopolymer Composite as the Sensing Medium

by Hassanein Shaban, Shih-Chun Yen, Mon-Juan Lee and Wei Lee

Biosensors 2021, 11(3), 81; https://0-doi-org.brum.beds.ac.uk/10.3390/bios11030081 - 13 Mar 2021

Cited by 10 | Viewed by 2371

Abstract

An optical and dielectric biosensor based on a liquid crystal (LC)–photopolymer composite was established in this study for the detection and quantitation of bovine serum albumin (BSA). When the nematic LC E7 was doped with 4-wt.% NOA65, a photo-curable prepolymer, and photopolymerized by [...] Read more.

An optical and dielectric biosensor based on a liquid crystal (LC)–photopolymer composite was established in this study for the detection and quantitation of bovine serum albumin (BSA). When the nematic LC E7 was doped with 4-wt.% NOA65, a photo-curable prepolymer, and photopolymerized by UV irradiation at 20 mW/cm² for 300 s, the limit of detection determined by image analysis of the LC optical texture and dielectric spectroscopic measurements was 3400 and 88 pg/mL for BSA, respectively, which were lower than those detected with E7 alone (10 μg/mL BSA). The photopolymerized NOA65, but not the prepolymer prior to UV exposure, contributed to the enhanced optical signal, and UV irradiation of pristine E7 in the absence of NOA65 had no effect on the optical texture. The effective tilt angle θ, calculated from the real-part dielectric constant ε’, decreased with increasing BSA concentration, providing strong evidence for the correlation of photopolymerized NOA65 to the intensified disruption in the vertically oriented LC molecules to enhance the optical and dielectric signals of BSA. The optical and dielectric anisotropy of LCs and the photo-curable dopant facilitate novel quantitative and signal amplification approaches to potential development of LC-based biosensors. Full article

(This article belongs to the Special Issue Electrical and Electro-Optical Biosensors)

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8 pages, 1129 KiB

Open AccessCommunication

Highly Sensitive Detection of CA 125 Protein with the Use of an n-Type Nanowire Biosensor

by Kristina A. Malsagova, Tatyana O. Pleshakova, Rafael A. Galiullin, Andrey F. Kozlov, Ivan D. Shumov, Vladimir P. Popov, Fedor V. Tikhonenko, Alexander V. Glukhov, Vadim S. Ziborov, Oleg F. Petrov, Vladimir E. Fortov, Alexander I. Archakov and Yuri D. Ivanov

Biosensors 2020, 10(12), 210; https://0-doi-org.brum.beds.ac.uk/10.3390/bios10120210 - 18 Dec 2020

Cited by 12 | Viewed by 2740

Abstract

The detection of CA 125 protein in a solution using a silicon-on-insulator (SOI)-nanowire biosensor with n-type chip has been experimentally demonstrated. The surface of nanowires was modified by covalent immobilization of antibodies against CA 125 in order to provide the biospecificity of the [...] Read more.

The detection of CA 125 protein in a solution using a silicon-on-insulator (SOI)-nanowire biosensor with n-type chip has been experimentally demonstrated. The surface of nanowires was modified by covalent immobilization of antibodies against CA 125 in order to provide the biospecificity of the target protein detection. We have demonstrated that the biosensor signal, which results from the biospecific interaction between CA 125 and the covalently immobilized antibodies, increases with the increase in the protein concentration. At that, the minimum concentration, at which the target protein was detectable with the SOI-nanowire biosensor, amounted to 1.5 × 10⁻¹⁶ M. Full article

(This article belongs to the Special Issue Electrical and Electro-Optical Biosensors)

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Review

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29 pages, 2609 KiB

Open AccessReview

Printed Electrochemical Biosensors: Opportunities and Metrological Challenges

by Emilio Sardini, Mauro Serpelloni and Sarah Tonello

Biosensors 2020, 10(11), 166; https://0-doi-org.brum.beds.ac.uk/10.3390/bios10110166 - 04 Nov 2020

Cited by 33 | Viewed by 4765

Abstract

Printed electrochemical biosensors have recently gained increasing relevance in fields ranging from basic research to home-based point-of-care. Thus, they represent a unique opportunity to enable low-cost, fast, non-invasive and/or continuous monitoring of cells and biomolecules, exploiting their electrical properties. Printing technologies represent powerful [...] Read more.

Printed electrochemical biosensors have recently gained increasing relevance in fields ranging from basic research to home-based point-of-care. Thus, they represent a unique opportunity to enable low-cost, fast, non-invasive and/or continuous monitoring of cells and biomolecules, exploiting their electrical properties. Printing technologies represent powerful tools to combine simpler and more customizable fabrication of biosensors with high resolution, miniaturization and integration with more complex microfluidic and electronics systems. The metrological aspects of those biosensors, such as sensitivity, repeatability and stability, represent very challenging aspects that are required for the assessment of the sensor itself. This review provides an overview of the opportunities of printed electrochemical biosensors in terms of transducing principles, metrological characteristics and the enlargement of the application field. A critical discussion on metrological challenges is then provided, deepening our understanding of the most promising trends in order to overcome them: printed nanostructures to improve the limit of detection, sensitivity and repeatability; printing strategies to improve organic biosensor integration in biological environments; emerging printing methods for non-conventional substrates; microfluidic dispensing to improve repeatability. Finally, an up-to-date analysis of the most recent examples of printed electrochemical biosensors for the main classes of target analytes (live cells, nucleic acids, proteins, metabolites and electrolytes) is reported. Full article

(This article belongs to the Special Issue Electrical and Electro-Optical Biosensors)

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16 pages, 2433 KiB

Open AccessReview

Printed Circuit Board (PCB) Technology for Electrochemical Sensors and Sensing Platforms

by Hamed Shamkhalichenar, Collin J. Bueche and Jin-Woo Choi

Biosensors 2020, 10(11), 159; https://0-doi-org.brum.beds.ac.uk/10.3390/bios10110159 - 30 Oct 2020

Cited by 57 | Viewed by 11882

Abstract

The development of various biosensors has revolutionized the healthcare industry by providing rapid and reliable detection capability. Printed circuit board (PCB) technology has a well-established industry widely available around the world. In addition to electronics, this technology has been utilized to fabricate electrical [...] Read more.

The development of various biosensors has revolutionized the healthcare industry by providing rapid and reliable detection capability. Printed circuit board (PCB) technology has a well-established industry widely available around the world. In addition to electronics, this technology has been utilized to fabricate electrical parts, including electrodes for different biological and chemical sensors. High reproducibility achieved through long-lasting standard processes and low-cost resulting from an abundance of competitive manufacturing services makes this fabrication method a prime candidate for patterning electrodes and electrical parts of biosensors. The adoption of this approach in the fabrication of sensing platforms facilitates the integration of electronics and microfluidics with biosensors. In this review paper, the underlying principles and advances of printed board circuit technology are discussed. In addition, an overview of recent advancements in the development of PCB-based biosensors is provided. Finally, the challenges and outlook of PCB-based sensors are elaborated. Full article

(This article belongs to the Special Issue Electrical and Electro-Optical Biosensors)

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