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Kadan-Jamal K, Jog A, Sophocleous M, Dotan T, Frumin P, Kuperberg Goshen T, Schuster S, Avni A, Shacham-Diamand Y. Sensing of gene expression in live cells using electrical impedance spectroscopy and DNA-functionalized gold nanoparticles. Biosens Bioelectron 2024; 252:116041. [PMID: 38401280 DOI: 10.1016/j.bios.2024.116041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/21/2023] [Accepted: 01/12/2024] [Indexed: 02/26/2024]
Abstract
A novel electrical impedance spectroscopy-based method for non-destructive sensing of gene expression in living cells is presented. The approach used takes advantage of the robustness and responsiveness of electrical impedance spectroscopy and the highly specific and selective nature of DNA hybridization. The technique uses electrical impedance spectroscopy and gold nanoparticles functionalized with single-stranded DNA complementary to an mRNA of interest to provide reliable, real-time, and quantifiable data on gene expression in live cells. The system was validated by demonstrating specific detection of the uidA mRNA, which codes for the β-glucuronidase (GUS) enzyme, in Solanum lycopersicum MsK8 cells. Gold nanoparticles were functionalized with single-stranded DNA oligonucleotides consisting of either a sequence complementary to uidA mRNA or an arbitrary sequence. The DNA-functionalized gold nanoparticles were mixed with cell suspensions, allowing the gold nanoparticles to penetrate into the cells. The impedance spectra of suspensions of cells with gold nanoparticles inserted within them were then studied. In suspensions of uidA-expressing cells and gold nanoparticles functionalized with the complementary single-stranded DNA oligonucleotide, the impedance magnitude in the frequency range of interest was significantly higher (146 %) in comparison to all other controls. Due to its highly selective nature, the methodology has the potential to be used as a precision agricultural sensing system for accurate and real-time detection of markers of stress, viral infection, disease, and normal physiological activities.
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Affiliation(s)
- Kian Kadan-Jamal
- Department of Materials Science and Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel; Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Aakash Jog
- Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.
| | - Marios Sophocleous
- Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel; Research & Development Department, eBOS Technologies Ltd., Nicosia, Cyprus
| | - Tali Dotan
- Department of Materials Science and Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel; Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Polina Frumin
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | | | - Silvia Schuster
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Adi Avni
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Yosi Shacham-Diamand
- Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel; Scojen Institute of Synthetic Biology, Reichmann University, Herzliya, Israel
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Nguyen TNP, Nguyen SH, Tran MT. Disposable impedance sensors based on novel hybrid MoS2 nanosheets and microparticles to detect Escherichia Coli DNA. PLoS One 2024; 19:e0299272. [PMID: 38422053 PMCID: PMC10903914 DOI: 10.1371/journal.pone.0299272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
The rapid and accurate detection of pathogenic bacteria is essential for food safety and public health. Conventional detection techniques, such as nucleic acid sequence-based amplification and polymerase chain reaction, are time-consuming and require specialized equipment and trained personnel. Here, we present quick, disposable impedance sensors based on the novel hybrid MoS2 nanomaterial for detecting Escherichia coli DNA. Our results indicate that the proposed sensors operate linearly between 10- 20 and 10-15 M concentrations, achieving an impressive detection limit of 10-20 M with the highest sensitivity observed at a 0.325 nM probe concentration sensor. Furthermore, the electrochemical impedance spectroscopy biosensors exhibited potential selectivity for Escherichia coli DNA over Bacillus subtilis and Vibrio proteolyticus DNA sequences. The findings offer a promising avenue for efficient and precise DNA detection, with potential implications for broader biotechnology and medical diagnostics applications.
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Affiliation(s)
- Tien Ngoc Phuc Nguyen
- College of Engineering and Computer Science, VinUniversity, Hanoi, Vietnam
- VinUni-Illinois Smart Health Center, VinUniversity, Hanoi, Vietnam
| | - Son Hai Nguyen
- School of Mechanical Engineering, Hanoi University of Science and Technology, Hanoi, Vietnam
| | - Mai Thi Tran
- College of Engineering and Computer Science, VinUniversity, Hanoi, Vietnam
- VinUni-Illinois Smart Health Center, VinUniversity, Hanoi, Vietnam
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Yang B, Gordiyenko K, Schäfer A, Dadfar SMM, Yang W, Riehemann K, Kumar R, Niemeyer CM, Hirtz M. Fluorescence Imaging Study of Film Coating Structure and Composition Effects on DNA Hybridization. ADVANCED NANOBIOMED RESEARCH 2023. [DOI: 10.1002/anbr.202200133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- Bingquan Yang
- Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMFi) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Klavdiya Gordiyenko
- Institute of Biological Interfaces (IBG-1) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Andreas Schäfer
- nanoAnalytics GmbH Heisenbergstraße 11 48149 Münster Germany
| | - Seyed Mohammad Mahdi Dadfar
- Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMFi) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Wenwu Yang
- Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMFi) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Kristina Riehemann
- Physical Institute and Center for Nanotechnology (CeNTech) University of Münster Wilhelm-Klemm-Straße 10 48149 Münster Germany
| | - Ravi Kumar
- Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMFi) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Christof M. Niemeyer
- Institute of Biological Interfaces (IBG-1) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Michael Hirtz
- Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMFi) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
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Liang Y, Zhang C. A novel PCR-free and label-free cloth-based DNA sensor for sensitive and rapid detection of Escherichia coli. Anal Chim Acta 2023; 1239:340630. [PMID: 36628741 DOI: 10.1016/j.aca.2022.340630] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 11/14/2022] [Indexed: 11/17/2022]
Abstract
BACKGROUND As is known to all, pathogenic bacteria have a serious impact on human health. The development of sensitive, simple, rapid and low-cost bacterial detection method is necessary. Nowadays, some conventional methods (such as plate count, polymerase chain reaction (PCR) and immunological techniques) can not meet the above needs. This work was aimed at providing a new method for addressing these unmet needs. RESULT This study proposed a novel PCR-free and label-free DNA sensor based on multiple linear hybridization chain reaction (ML-HCR) and cloth-based closed bipolar electrochemiluminescence for sensitive and rapid detection of Escherichia coli (E. coli). The target DNA can be obtained from the E. coli genomic DNA by using the restriction enzyme instead of PCR. The auxiliary probe-triggered ML-HCR is carried out with continuous hybridization of two hairpin DNA, and as a result the double stranded DNA is formed to provide a large number of binding sites for Ru(bpy)32+. The whole detection is PCR-free and label-free, and thus the detection procedure is easier and faster. Under optimized conditions, the linear detection range was from 102 to 107 CFU/mL, and the detection limit was low to 38 CFU/mL. In addition, the proposed DNA sensor has an acceptable selectivity, stability and reproducibility, and is successfully applied to detect E. coli in milk samples with the recoveries from 96.24% to 105.98%. SIGNIFICANCE The proposed DNA sensor has broad application prospects in the fields of bacterial detection and gene diagnose. Further, this method has potential to be extended for establishing miniaturized, integrated, and automated detection system.
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Affiliation(s)
- Yi Liang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, China
| | - Chunsun Zhang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, China.
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Chomean S, Nakkam N, Tassaneeyakul W, Attapong J, Kaset C. Development of label-free electrochemical impedance spectroscopy for the detection of HLA-B*15:02 and HLA-B*15:21 for the prevention of carbamazepine-induced Stevens-Johnson syndrome. Anal Biochem 2022; 658:114931. [PMID: 36191668 DOI: 10.1016/j.ab.2022.114931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/20/2022] [Accepted: 09/23/2022] [Indexed: 11/01/2022]
Abstract
BACKGROUND Carbamazepine (CBZ) is an FDA-approved anticonvulsant that is widely used to treat epilepsy, bipolar disorder, trigeminal neuralgia and chronic pain. Several studies have reported a strong association between HLA-B*15:02 and carbamazepine-induced Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). However, the HLA-B75 serotype (HLA-B*15:02, HLA-B*15:08, HLA-B*15:11 and HLA-B*15:21) has been found in patients with carbamazepine-induced SJS/TEN. METHODS This study aimed to develop label-free electrochemical impedance spectroscopy (EIS) for the detection of HLA-B*15:02 and HLA-B*15:21 after PCR-SSP amplification. A total of 208 DNA samples were tested. The impedance was measured and compared to standard gel electrophoresis. RESULTS The developed label-free EIS identified HLA-B*15:02 and HLA-B*15:21 alleles with 100% sensitivity (95% CI: 86.773%-100.000%) and 95.05% specificity (95% CI: 90.821%-97.714%), comparable to commercial DMSc 15:02 detection kits. CONCLUSIONS We successfully developed a novel PCR-SSP associated with signal impedance changes to detect the HLA-B*15:02 allele and HLA-B*15:21 without downstream amplicon size analysis that is suitable for screening individuals before indication of CBZ therapy.
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Affiliation(s)
- Sirinart Chomean
- Department of Medical Technology, Faculty of Allied Health Sciences, Thammasat University, Pathumthani, Thailand; Thammasat University Research Unit in Medical Technology and Precision Medicine Innovation, Thailand
| | - Nontaya Nakkam
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | | | - Jirapat Attapong
- Department of Medical Technology, Faculty of Allied Health Sciences, Thammasat University, Pathumthani, Thailand; Thammasat University Research Unit in Medical Technology and Precision Medicine Innovation, Thailand
| | - Chollanot Kaset
- Department of Medical Technology, Faculty of Allied Health Sciences, Thammasat University, Pathumthani, Thailand; Thammasat University Research Unit in Medical Technology and Precision Medicine Innovation, Thailand.
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Wasiewska LA, Diaz FG, Shao H, Burgess CM, Duffy G, O'Riordan A. Highly sensitive electrochemical sensor for the detection of Shiga toxin-producing E. coli (STEC) using interdigitated micro-electrodes selectively modified with a chitosan-gold nanocomposite. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.140748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Urso M, Tumino S, Bruno E, Bordonaro S, Marletta D, Loria GR, Avni A, Shacham-Diamand Y, Priolo F, Mirabella S. Ultrasensitive Electrochemical Impedance Detection of Mycoplasma agalactiae DNA by Low-Cost and Disposable Au-Decorated NiO Nanowall Electrodes. ACS APPLIED MATERIALS & INTERFACES 2020; 12:50143-50151. [PMID: 33078934 DOI: 10.1021/acsami.0c14679] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Nanostructured electrodes detecting bacteria or viruses through DNA hybridization represent a promising method, which may be useful in on-field applications where PCR-based methods are very expensive, time-consuming, and require trained personnel. Indeed, electrochemical sensors combine disposability, fast response, high sensitivity, and portability. Here, a low-cost and high-surface-area electrode, based on Au-decorated NiO nanowalls, demonstrates a highly sensitive PCR-free detection of a real sample of Mycoplasma agalactiae (Ma) DNA. NiO nanowalls, synthesized by aqueous methods, thermal annealing, and Au decoration, by electroless deposition, ensure a high-surface-area platform for successful immobilization of Ma thiolated probe DNA. The morphological, chemical, and electrochemical properties of the electrode were characterized, and a reproducible detection of synthetic Ma DNA was observed and investigated by impedance measurements. Electrochemical impedance spectroscopy (EIS) ascribed the origin of impedance signal to the Ma DNA hybridization with its probe immobilized onto the electrode. The electrode successfully discriminates between DNA extracted from healthy and infected sheep milk, showing the ability to detect Ma DNA in concentrations as low as 53 ± 2 copy number μL-1. The Au-decorated NiO nanowall electrode represents a promising route toward PCR-free, disposable, rapid, and molecular detection.
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Affiliation(s)
- Mario Urso
- Dipartimento di Fisica e Astronomia "Ettore Majorana", Università di Catania, and IMM-CNR, via S. Sofia 64, 95123 Catania, Italy
| | - Serena Tumino
- Dipartimento di Agricoltura, Alimentazione e Ambiente, Università di Catania, via Valdisavoia 5, 95123 Catania, Italy
- OIE Reference Laboratory for Contagious Agalactia-Istituto Zooprofilattico Sperimentale della Sicilia, via Gino Marinuzzi 3, 90129 Palermo, Italy
| | - Elena Bruno
- Dipartimento di Fisica e Astronomia "Ettore Majorana", Università di Catania, and IMM-CNR, via S. Sofia 64, 95123 Catania, Italy
| | - Salvo Bordonaro
- Dipartimento di Agricoltura, Alimentazione e Ambiente, Università di Catania, via Valdisavoia 5, 95123 Catania, Italy
| | - Donata Marletta
- Dipartimento di Agricoltura, Alimentazione e Ambiente, Università di Catania, via Valdisavoia 5, 95123 Catania, Italy
| | - Guido Ruggero Loria
- OIE Reference Laboratory for Contagious Agalactia-Istituto Zooprofilattico Sperimentale della Sicilia, via Gino Marinuzzi 3, 90129 Palermo, Italy
| | - Adi Avni
- School of Plant Sciences and Food Security, Tel Aviv University, Tel-Aviv 69978, Israel
| | - Yosi Shacham-Diamand
- Department of Physical Electronics, School of Electrical Engineering and Department of Materials Science and Engineering, Faculty of Engineering, Tel Aviv University, Tel-Aviv 69978, Israel
- TAU/TiET Food Security Centre of Excellence (T2FSCOE), Thapar Institute of Engineering and Technology, Patiala 147004, Punjab, India
| | - Francesco Priolo
- Dipartimento di Fisica e Astronomia "Ettore Majorana", Università di Catania, and IMM-CNR, via S. Sofia 64, 95123 Catania, Italy
| | - Salvo Mirabella
- Dipartimento di Fisica e Astronomia "Ettore Majorana", Università di Catania, and IMM-CNR, via S. Sofia 64, 95123 Catania, Italy
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Tian Y, Liang T, Zhu P, Chen Y, Chen W, Du L, Wu C, Wang P. Label-Free Detection of E. coli O157:H7 DNA Using Light-Addressable Potentiometric Sensors with Highly Oriented ZnO Nanorod Arrays. SENSORS (BASEL, SWITZERLAND) 2019; 19:E5473. [PMID: 31842267 PMCID: PMC6960909 DOI: 10.3390/s19245473] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/07/2019] [Accepted: 12/09/2019] [Indexed: 12/26/2022]
Abstract
The detection of bacterial deoxyribonucleic acid (DNA) is of great significance in the quality control of food and water. In this study, a light-addressable potentiometric sensor (LAPS) deposited with highly oriented ZnO nanorod arrays (NRAs) was used for the label-free detection of single-stranded bacterial DNA (ssDNA). A functional, sensitive surface for the detection of Escherichia coli (E. coli) O157:H7 DNA was prepared by the covalent immobilization of the specific probe single-stranded DNA (ssDNA) on the LAPS surface. The functional surface was exposed to solutions containing the target E. coli ssDNA molecules, which allowed for the hybridization of the target ssDNA with the probe ssDNA. The surface charge changes induced by the hybridization of the probe ssDNA with the target E. coli ssDNA were monitored using LAPS measurements in a label-free manner. The results indicate that distinct signal changes can be registered and recorded to detect the target E. coli ssDNA. The lower detection limit of the target ssDNA corresponded to 1.0 × 102 colony forming units (CFUs)/mL of E. coli O157:H7 cells. All the results demonstrate that this DNA biosensor, based on the electrostatic detection of ssDNA, provides a novel approach for the sensitive and effective detection of bacterial DNA, which has promising prospects and potential applications in the quality control of food and water.
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Affiliation(s)
- Yulan Tian
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an 710061, China; (Y.T.); (P.Z.); (Y.C.); (W.C.); (L.D.)
| | - Tao Liang
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China;
| | - Ping Zhu
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an 710061, China; (Y.T.); (P.Z.); (Y.C.); (W.C.); (L.D.)
| | - Yating Chen
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an 710061, China; (Y.T.); (P.Z.); (Y.C.); (W.C.); (L.D.)
| | - Wei Chen
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an 710061, China; (Y.T.); (P.Z.); (Y.C.); (W.C.); (L.D.)
| | - Liping Du
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an 710061, China; (Y.T.); (P.Z.); (Y.C.); (W.C.); (L.D.)
| | - Chunsheng Wu
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an 710061, China; (Y.T.); (P.Z.); (Y.C.); (W.C.); (L.D.)
| | - Ping Wang
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China;
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Application of Aptamer-Based Biosensor for Rapid Detection of Pathogenic Escherichia coli. SENSORS 2018; 18:s18082518. [PMID: 30071682 PMCID: PMC6111995 DOI: 10.3390/s18082518] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/24/2018] [Accepted: 07/26/2018] [Indexed: 12/17/2022]
Abstract
Pathogenic Escherichia coli (E. coli) widely exist in Nature and have always been a serious threat to the human health. Conventional colony forming units counting-based methods are quite time consuming and not fit for rapid detection for E. coli. Therefore, novel strategies for improving detection efficiency and sensitivity are in great demand. Aptamers have been widely used in various sensors due to their extremely high affinity and specificity. Successful applications of aptamers have been found in the rapid detection of pathogenic E. coli. Herein, we present the latest advances in screening of aptamers for E. coli, and review the preparation and application of aptamer-based biosensors in rapid detection of E. coli. Furthermore, the problems and new trends in these aptamer-based biosensors for rapid detection of pathogenic microorganism are also discussed.
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A universal and label-free impedimetric biosensing platform for discrimination of single nucleotide substitutions in long nucleic acid strands. Biosens Bioelectron 2018. [PMID: 29524915 DOI: 10.1016/j.bios.2018.02.059] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We report a label-free universal biosensing platform for highly selective detection of long nucleic acid strands. The sensor consists of an electrode-immobilized universal stem-loop (USL) probe and two adaptor strands that form a 4J structure in the presence of a specific DNA/RNA analyte. The sensor was characterized by electrochemical impedance spectroscopy (EIS) using K3[Fe(CN)6]/K4[Fe(CN)6] redox couple in solution. An increase in charge transfer resistance (RCT) was observed upon 4J structure formation, the value of which depends on the analyte length. Cyclic voltammetry (CV) was used to further characterize the sensor and monitor the electrochemical reaction in conjunction with thickness measurements of the mixed DNA monolayer obtained using spectroscopic ellipsometry. In addition, the electron transfer was calculated at the electrode/electrolyte interface using a rotating disk electrode. Limits of detection in the femtomolar range were achieved for nucleic acid targets of different lengths (22 nt, 60 nt, 200 nt). The sensor produced only a background signal in the presence of single base mismatched analytes, even in hundred times excess in concentration. This label-free and highly selective biosensing platform is versatile and can be used for universal detection of nucleic acids of varied lengths which could revolutionize point of care diagnostics for applications such as bacterial or cancer screening.
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