Biosensors

Editorial

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Open AccessEditorial

Special Issue on Organic Electronic Bio-Devices

by Luisa Torsi

Biosensors 2013, 3(1), 116-119; https://doi.org/10.3390/bios3010116 - 28 Feb 2013

Cited by 4 | Viewed by 5964

Abstract

The aim of the present editorial is to briefly summarize the current scientific and technological accomplishments in the field of organic electronic biosensors as described in the articles published in this Special Issue. By definition, a biosensor is a robust analytical device that [...] Read more.

The aim of the present editorial is to briefly summarize the current scientific and technological accomplishments in the field of organic electronic biosensors as described in the articles published in this Special Issue. By definition, a biosensor is a robust analytical device that combines a biological recognition element (e.g., antibodies, enzymes, cells) with a transducer. Organic electronic bio-devices are considered as potentially reliable substitutes of conventional and rather expensive analytical techniques employed for several applications such as medical diagnosis, food safety and environment pollution monitoring. Some insights into the selection and immobilization of recognition elements, signal amplification, fabrication techniques and analytical performance of biosensing devices will be presented. Full article

(This article belongs to the Special Issue Organic Electronic Bio-Devices)

Research

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Open AccessArticle

Quinone-Based Polymers for Label-Free and Reagentless Electrochemical Immunosensors: Application to Proteins, Antibodies and Pesticides Detection

by Benoit Piro, Steeve Reisberg, Guillaume Anquetin, Huynh-Thien Duc and Minh-Chau Pham

Biosensors 2013, 3(1), 58-76; https://doi.org/10.3390/bios3010058 - 14 Jan 2013

Cited by 29 | Viewed by 11496

Abstract

Polyquinone derivatives are widely recognized in the literature for their remarkable properties, their biocompatibility, simple synthesis, and easy bio-functionalization. We have shown that polyquinones present very stable electroactivity in neutral aqueous medium within the cathodic potential domain avoiding side oxidation of interfering species. [...] Read more.

Polyquinone derivatives are widely recognized in the literature for their remarkable properties, their biocompatibility, simple synthesis, and easy bio-functionalization. We have shown that polyquinones present very stable electroactivity in neutral aqueous medium within the cathodic potential domain avoiding side oxidation of interfering species. Besides, they can act as immobilized redox transducers for probing biomolecular interactions in sensors. Our group has been working on devices based on such modified electrodes with a view to applications for proteins, antibodies and organic pollutants using a reagentless label-free electrochemical immunosensor format. Herein, these developments are briefly reviewed and put into perspective. Full article

(This article belongs to the Special Issue Organic Electronic Bio-Devices)

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575 KiB

Open AccessArticle

Sensing of EGTA Mediated Barrier Tissue Disruption with an Organic Transistor

by Scherrine Tria, Leslie H. Jimison, Adel Hama, Manuelle Bongo and Róisín M. Owens

Biosensors 2013, 3(1), 44-57; https://doi.org/10.3390/bios3010044 - 8 Jan 2013

Cited by 39 | Viewed by 10628

Abstract

Barrier tissue protects the body against external factors by restricting the passage of molecules. The gastrointestinal epithelium is an example of barrier tissue with the primary purpose of allowing the passage of ions and nutrients, while restricting the passage of pathogens and toxins. [...] Read more.

Barrier tissue protects the body against external factors by restricting the passage of molecules. The gastrointestinal epithelium is an example of barrier tissue with the primary purpose of allowing the passage of ions and nutrients, while restricting the passage of pathogens and toxins. It is well known that the loss of barrier function can be instigated by a decrease in extracellular calcium levels, leading to changes in protein conformation and an increase in paracellular transport. In this study, ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetra acetic acid (EGTA), a calcium chelator, was used to disrupt the gastrointestinal epithelial barrier. The effect of EGTA on barrier tissue was monitored by a novel label-free method based on an organic electrochemical transistor (OECT) integrated with living cells and validated against conventional methods for measuring barrier tissue integrity. We demonstrate that the OECT can detect breaches in barrier tissue upon exposure to EGTA with the same sensitivity as existing methods but with increased temporal resolution. Due to the potential of low cost processing techniques and the flexibility in design associated with organic electronics, the OECT has great potential for high-throughput, disposable sensing and diagnostics. Full article

(This article belongs to the Special Issue Organic Electronic Bio-Devices)

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Open AccessArticle

Application of Paper-Supported Printed Gold Electrodes for Impedimetric Immunosensor Development

by Petri Ihalainen, Himadri Majumdar, Tapani Viitala, Björn Törngren, Tuomas Närjeoja, Anni Määttänen, Jawad Sarfraz, Harri Härmä, Marjo Yliperttula, Ronald Österbacka and Jouko Peltonen

Biosensors 2013, 3(1), 1-17; https://doi.org/10.3390/bios3010001 - 27 Dec 2012

Cited by 29 | Viewed by 12300

Abstract

In this article, we report on the formation and mode-of-operation of an affinity biosensor, where alternate layers of biotin/streptavidin/biotinylated-CRP-antigen/anti-CRP antibody are grown on printed gold electrodes on disposable paper-substrates. We have successfully demonstrated and detected the formation of consecutive layers of supra-molecular protein [...] Read more.

In this article, we report on the formation and mode-of-operation of an affinity biosensor, where alternate layers of biotin/streptavidin/biotinylated-CRP-antigen/anti-CRP antibody are grown on printed gold electrodes on disposable paper-substrates. We have successfully demonstrated and detected the formation of consecutive layers of supra-molecular protein assembly using an electrical (impedimetric) technique. The formation process is also supplemented and verified using conventional surface plasmon resonance (SPR) measurements and surface sensitive characterization techniques, such as X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The article provides a possible biosensor development scheme, where—(1) fabrication of paper substrate (2) synthesis of gold nanoparticle inks (3) inkjet printing of gold electrodes on paper (4) formation of the biorecognition layers on the gold electrodes and (5) electrical (impedimetric) analysis of growth—all are coupled together to form a test-structure for a recyclable and inexpensive point-of-care diagnostic platform. Full article

(This article belongs to the Special Issue Organic Electronic Bio-Devices)

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855 KiB

Open AccessArticle

Synthesis of a Functionalized Polypyrrole Coated Electrotextile for Use in Biosensors

by Shannon K. McGraw, Evangelyn Alocilja, Andre Senecal and Kris Senecal

Biosensors 2012, 2(4), 465-478; https://doi.org/10.3390/bios2040465 - 29 Nov 2012

Cited by 10 | Viewed by 7652

Abstract

An electrotextile with a biosensing focus composed of conductive polymer coated microfibers that contain functional attachment sites for biorecognition elements was developed. Experiments were conducted to select a compound with a pendant functional group for inclusion in the polymer, a fiber platform, and [...] Read more.

An electrotextile with a biosensing focus composed of conductive polymer coated microfibers that contain functional attachment sites for biorecognition elements was developed. Experiments were conducted to select a compound with a pendant functional group for inclusion in the polymer, a fiber platform, and polymerization solvent. The effects of dopant inclusion and post-polymerization wash steps were also analyzed. Finally, the successful attachment of avidin, which was then used to capture biotin, to the electrotextile was achieved. The initial results show a nonwoven fiber matrix can be successfully coated in a conductive, functionalized polymer while still maintaining surface area and fiber durability. A polypropylene fiber platform with a conductive polypyrrole coating using iron (III) chloride as an oxidant, water as a solvent, and 5-sulfosalicylic acid as a dopant exhibited the best coating consistency, material durability, and lowest resistance. Biological attachment of avidin was achieved on the fibers through the inclusion of a carboxyl functional group via 3-thiopheneacetic acid in the monomer. The immobilized avidin was then successfully used to capture biotin. This was confirmed through the use of fluorescent quantum dots and confocal microscopy. A preliminary electrochemical experiment using avidin for biotin detection was conducted. This technology will be extremely useful in the formation of electrotextiles for use in biosensor systems. Full article

(This article belongs to the Special Issue Organic Electronic Bio-Devices)

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Open AccessArticle

Functional Conducting Polymers via Thiol-ene Chemistry

by Kathleen E. Feldman and David C. Martin

Biosensors 2012, 2(3), 305-317; https://doi.org/10.3390/bios2030305 - 31 Aug 2012

Cited by 16 | Viewed by 10018

Abstract

We demonstrate here that thiol-ene chemistry can be used to provide side-chain functionalized monomers based on 3,4-propylenedioxythiophene (ProDOT) containing ionic, neutral, hydrophobic, and hydrophilic side chains. All reactions gave high yields and purification could generally be accomplished through precipitation. These monomers were polymerized [...] Read more.

We demonstrate here that thiol-ene chemistry can be used to provide side-chain functionalized monomers based on 3,4-propylenedioxythiophene (ProDOT) containing ionic, neutral, hydrophobic, and hydrophilic side chains. All reactions gave high yields and purification could generally be accomplished through precipitation. These monomers were polymerized either chemically or electro-chemically to give soluble materials or conductive films, respectively. This strategy provides for facile tuning of the solubility, film surface chemistry, and film morphology of this class of conducting polymers. Full article

(This article belongs to the Special Issue Organic Electronic Bio-Devices)

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Review

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Open AccessReview

Biomimetic Strategies for Sensing Biological Species

by Munawar Hussain, Judith Wackerlig and Peter A. Lieberzeit

Biosensors 2013, 3(1), 89-107; https://doi.org/10.3390/bios3010089 - 6 Feb 2013

Cited by 74 | Viewed by 14627

Abstract

The starting point of modern biosensing was the application of actual biological species for recognition. Increasing understanding of the principles underlying such recognition (and biofunctionality in general), however, has triggered a dynamic field in chemistry and materials sciences that aims at joining the [...] Read more.

The starting point of modern biosensing was the application of actual biological species for recognition. Increasing understanding of the principles underlying such recognition (and biofunctionality in general), however, has triggered a dynamic field in chemistry and materials sciences that aims at joining the best of two worlds by combining concepts derived from nature with the processability of manmade materials, e.g., sensitivity and ruggedness. This review covers different biomimetic strategies leading to highly selective (bio)chemical sensors: the first section covers molecularly imprinted polymers (MIP) that attempt to generate a fully artificial, macromolecular mold of a species in order to detect it selectively. A different strategy comprises of devising polymer coatings to change the biocompatibility of surfaces that can also be used to immobilized natural receptors/ligands and thus stabilize them. Rationally speaking, this leads to self-assembled monolayers closely resembling cell membranes, sometimes also including bioreceptors. Finally, this review will highlight some approaches to generate artificial analogs of natural recognition materials and biomimetic approaches in nanotechnology. It mainly focuses on the literature published since 2005. Full article

(This article belongs to the Special Issue Organic Electronic Bio-Devices)

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1077 KiB

Open AccessReview

Isothermal Amplification Methods for the Detection of Nucleic Acids in Microfluidic Devices

by Laura Maria Zanoli and Giuseppe Spoto

Biosensors 2013, 3(1), 18-43; https://doi.org/10.3390/bios3010018 - 27 Dec 2012

Cited by 205 | Viewed by 20103

Abstract

Diagnostic tools for biomolecular detection need to fulfill specific requirements in terms of sensitivity, selectivity and high-throughput in order to widen their applicability and to minimize the cost of the assay. The nucleic acid amplification is a key step in DNA detection assays. [...] Read more.

Diagnostic tools for biomolecular detection need to fulfill specific requirements in terms of sensitivity, selectivity and high-throughput in order to widen their applicability and to minimize the cost of the assay. The nucleic acid amplification is a key step in DNA detection assays. It contributes to improving the assay sensitivity by enabling the detection of a limited number of target molecules. The use of microfluidic devices to miniaturize amplification protocols reduces the required sample volume and the analysis times and offers new possibilities for the process automation and integration in one single device. The vast majority of miniaturized systems for nucleic acid analysis exploit the polymerase chain reaction (PCR) amplification method, which requires repeated cycles of three or two temperature-dependent steps during the amplification of the nucleic acid target sequence. In contrast, low temperature isothermal amplification methods have no need for thermal cycling thus requiring simplified microfluidic device features. Here, the use of miniaturized analysis systems using isothermal amplification reactions for the nucleic acid amplification will be discussed. Full article

(This article belongs to the Special Issue Organic Electronic Bio-Devices)

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