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Impedimetric Aptamer-Based Biosensors: Principles and Techniques. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2020; 174:17-41. [PMID: 32328684 DOI: 10.1007/10_2019_113] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Aptamers are a specific class of ligands with high affinities comparable to antibodies, which are selected and synthesized in vitro. In combination with impedance spectroscopy as sensitive measurement method, we gain a class of biosensors with high potential for handheld devices and point-of-care tests. In this review, we report on recent advances in aptamer-based impedimetric biosensors. Besides giving a short summary of electrochemical measurement techniques, the most exciting innovative developments of detection strategies in the last decades are reviewed. Finally, important criteria for the comparison of aptamer-based biosensors are discussed.
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Du Y, Zhen SJ, Li B, Byrom M, Jiang YS, Ellington AD. Engineering Signaling Aptamers That Rely on Kinetic Rather Than Equilibrium Competition. Anal Chem 2016; 88:2250-7. [PMID: 26750592 DOI: 10.1021/acs.analchem.5b03930] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
During the past decade, aptasensors have largely been designed on the basis of the notion that ligand-modulated equilibration between aptamer conformations could be exploited for sensing. One implementation of this strategy has been to denature the aptamer with an antisense oligonucleotide, wait for dissociation of the antisense oligonucleotide, and stabilize the folded, signaling conformer with a ligand. However, there is a large kinetic barrier associated with releasing the oligonucleotide from the aptamer to again obtain an active, binding conformation. If the length of the antisense oligonucleotide is decreased to make dissociation from the aptamer more favorable, higher background signals are observed. To improve the general methodology for developing aptasensors, we have developed a novel and robust strategy for aptasensor design in which an oligonucleotide kinetically competes with the ligand for binding rather than having to be released from a stable duplex. While the oligonucleotide can induce conformational change, it initially chooses between the aptamer and a molecular beacon (MB), a process that does not require a lengthy pre-equilibration. Using an anti-ricin aptamer as a starting point, we developed a "competitive" aptasensor with a measured limit of detection (LOD) of 30 nM with an optical readout and as low as 3 nM for ricin toxin A-chain (RTA) detection on an electrochemical platform.
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Affiliation(s)
- Yan Du
- Institute for Cellular and Molecular Biology, Center for Systems and Synthetic Biology, and Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Shu Jun Zhen
- Institute for Cellular and Molecular Biology, Center for Systems and Synthetic Biology, and Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States.,Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , 400715, Chongqing, P.R. China
| | - Bingling Li
- Institute for Cellular and Molecular Biology, Center for Systems and Synthetic Biology, and Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Michelle Byrom
- Institute for Cellular and Molecular Biology, Center for Systems and Synthetic Biology, and Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Yu Sherry Jiang
- Institute for Cellular and Molecular Biology, Center for Systems and Synthetic Biology, and Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Andrew D Ellington
- Institute for Cellular and Molecular Biology, Center for Systems and Synthetic Biology, and Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States
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Stenken JA, Poschenrieder AJ. Bioanalytical chemistry of cytokines--a review. Anal Chim Acta 2015; 853:95-115. [PMID: 25467452 PMCID: PMC4717841 DOI: 10.1016/j.aca.2014.10.009] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/30/2014] [Accepted: 10/08/2014] [Indexed: 02/06/2023]
Abstract
Cytokines are bioactive proteins produced by many different cells of the immune system. Due to their role in different inflammatory disease states and maintaining homeostasis, there is enormous clinical interest in the quantitation of cytokines. The typical standard methods for quantitation of cytokines are immunoassay-based techniques including enzyme-linked immusorbent assays (ELISA) and bead-based immunoassays read by either standard or modified flow cytometers. A review of recent developments in analytical methods for measurements of cytokine proteins is provided. This review briefly covers cytokine biology and the analysis challenges associated with measurement of these biomarker proteins for understanding both health and disease. New techniques applied to immunoassay-based assays are presented along with the uses of aptamers, electrochemistry, mass spectrometry, optical resonator-based methods. Methods used for elucidating the release of cytokines from single cells as well as in vivo collection methods are described.
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Affiliation(s)
- Julie A Stenken
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Andreas J Poschenrieder
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA; Pharmaceutical Radiochemistry, Technische Universität München, Walther-Meißner-Street 3, D-85748 Garching, Germany
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