Pre-concentration of microRNAs by LNA-modified magnetic beads for enhancement of electrochemical detection

AbstractMicroRNAs are extremely promising candidates for early cancer diagnosis and prognosis. The levels of circulating microRNAs provide valuable information about cancer disease at its early stages. However, the levels of microRNAs that need to be detected are extremely low and difficult to discriminate from a large pool of oligonucleotides. There is the need for accurate, rapid and sensitive detection methodologies for detection of microRNAs. We developed electrochemical impedance spectroscopy peptide nucleic acid (PNA)-based sensors that can detect miRNAs in diluted serum with a limit of detection of 0.38 fM. In order to further improve the accuracy and reliability of the sensors, we developed an assay using magnetic beads for simple and rapid fishing of target microRNAs from solution and its pre-concentration prior to electrochemical detection. Our methodology utilizes magnetic beads for the capture of the target microRNA from solution and brings the concentrated sample to the sensor surface. We modify the magnetic beads with locked nucleic acids (LNA), which have high affinity and specificity to their complementary microRNA sequence. The separated and concentrated microRNA is then detected using the PNA-based sensors. By exposing the sensing electrodes only to the captured microRNAs, interferences from other nucleotides or biomolecules from the sample are eliminated.

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Novel Competitive Voltammetric Aptasensor Based on Electrospun Carbon Nanofibers-Gold Nanoparticles Modified Graphite Electrode for Salmonella enterica serovar Detection

Biointerface Research in Applied Chemistry ◽

10.33263/briac112.87028715 ◽

2020 ◽

Vol 11 (2) ◽

pp. 8702-8715

Keyword(s):

Gold Nanoparticles ◽

Carbon Nanofibers ◽

Electrochemical Detection ◽

Salmonella Enterica ◽

Electrochemical Impedance ◽

Graphite Electrode ◽

Limit Of Detection ◽

Differential Pulse ◽

Pencil Graphite Electrode ◽

Experimental Conditions

Salmonella enterica is considered one of the most common bacterial agent causes of acute gastroenteritis and foodborne illness in humans worldwide. Antibiotic-resistant is considered as a major problem in Salmonella enterica Serovar. This study introduces a new simple and sensitive aptasensor based on chitosan (Chi)-electrospun carbon nanofibers (CNF) /gold nanoparticles (GNPs) decorated pencil graphite electrode (GE) as a novel platform for electrochemical detection of Salmonella enterica Serovar. A Salmonella-specific recognition aptamer ssDNA sequence was used in the development of this voltammetric biosensor. Electrochemical behaviors of electrodes; unmodified GE, CNF-Chi/GE, GNPs/CNF-Chi/GE, GNPs/CNF-Chi/GEs linked with the aptamer were studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). After the optimization of experimental conditions (e.g., CNF concentration, pH, and incubation time), electrochemical detection of Salmonella was performed via differential pulse voltammetry (DPV) in methylene blue solution. The designed aptasensor exhibited a linear range of 10 to 105 (CFU/mL) with the limit of detection (LOD) 1.223 (Cfu/mL) for Salmonella. This aptasensor displayed excellent selectivity and remarkable sensitivity in terms of the detection of Salmonella enterica even in the real samples as compared to the polymerase chain reaction (PCR) technique. The constructed aptasensor is a highly sensitive sensor for the detection of Salmonella enterica and also can be tailored for various other targets.

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Label-Free Electrochemical Detection of S. mutans Exploiting Commercially Fabricated Printed Circuit Board Sensing Electrodes

Micromachines ◽

10.3390/mi10090575 ◽

2019 ◽

Vol 10 (9) ◽

pp. 575 ◽

Cited By ~ 5

Author(s):

Gorachand Dutta ◽

Abdoulie A. Jallow ◽

Debjani Paul ◽

Despina Moschou

Keyword(s):

Electrochemical Detection ◽

Printed Circuit Board ◽

Electrochemical Impedance ◽

Limit Of Detection ◽

Charge Transfer Resistance ◽

Circuit Board ◽

Label Free ◽

Electrochemical Impedance Spectra ◽

Transfer Resistance ◽

Printed Circuit

This paper reports for the first time printed-circuit-board (PCB)-based label-free electrochemical detection of bacteria. The demonstrated immunosensor was implemented on a PCB sensing platform which was designed and fabricated in a standard PCB manufacturing facility. Bacteria were directly captured on the PCB sensing surface using a specific, pre-immobilized antibody. Electrochemical impedance spectra (EIS) were recorded and used to extract the charge transfer resistance (Rct) value for the different bacteria concentrations under investigation. As a proof-of-concept, Streptococcus mutans (S. mutans) bacteria were quantified in a phosphate buffered saline (PBS) buffer, achieving a limit of detection of 103 CFU/mL. Therefore, the proposed biosensor is an attractive candidate for the development of a simple and robust point-of-care diagnostic platform for bacteria identification, exhibiting good sensitivity, high selectivity, and excellent reproducibility.

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Peptide nucleic acid modified magnetic beads for intercalator based electrochemical detection of DNA hybridization

Science and Technology of Advanced Materials ◽

10.1016/j.stam.2004.01.009 ◽

2004 ◽

Vol 5 (3) ◽

pp. 351-357 ◽

Cited By ~ 36

Author(s):

Kagan Kerman ◽

Yasutaka Matsubara ◽

Yasutaka Morita ◽

Yuzuru Takamura ◽

Eiichi Tamiya

Keyword(s):

Nucleic Acid ◽

Electrochemical Detection ◽

Dna Hybridization ◽

Peptide Nucleic Acid ◽

Magnetic Beads

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A Reliable BioFET Immunosensor for Detection of p53 Tumour Suppressor in Physiological-Like Environment

Sensors ◽

10.3390/s20216364 ◽

2020 ◽

Vol 20 (21) ◽

pp. 6364

Author(s):

Chiara Baldacchini ◽

Antonino Francesco Montanarella ◽

Luca Francioso ◽

Maria Assunta Signore ◽

Salvatore Cannistraro ◽

...

Keyword(s):

Limit Of Detection ◽

Free Field ◽

Direct Interaction ◽

Tumour Suppressor ◽

Label Free ◽

Buffer Solution ◽

Voltage Versus ◽

Diagnosis And Prognosis ◽

Early Cancer Diagnosis ◽

Permeable Polymer

The concentration of wild-type tumour suppressor p53wt in cells and blood has a clinical significance for early diagnosis of some types of cancer. We developed a disposable, label-free, field-effect transistor-based immunosensor (BioFET), able to detect p53wt in physiological buffer solutions, over a wide concentration range. Microfabricated, high-purity gold electrodes were used as single-use extended gates (EG), which avoid direct interaction between the transistor gate and the biological solution. Debye screening, which normally hampers target charge effect on the FET gate potential and, consequently, on the registered FET drain-source current, at physiological ionic strength, was overcome by incorporating a biomolecule-permeable polymer layer on the EG electrode surface. Determination of an unknown p53wt concentration was obtained by calibrating the variation of the FET threshold voltage versus the target molecule concentration in buffer solution, with a sensitivity of 1.5 ± 0.2 mV/decade. The BioFET specificity was assessed by control experiments with proteins that may unspecifically bind at the EG surface, while 100pM p53wt concentration was established as limit of detection. This work paves the way for fast and highly sensitive tools for p53wt detection in physiological fluids, which deserve much interest in early cancer diagnosis and prognosis.

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A Graphene-PEDOT:PSS Modified Paper-Based Aptasensor for Electrochemical Impedance Spectroscopy Detection of Tumor Marker

Sensors ◽

10.3390/s20051372 ◽

2020 ◽

Vol 20 (5) ◽

pp. 1372 ◽

Cited By ~ 4

Author(s):

Yi-Kuang Yen ◽

Chen-Hsiang Chao ◽

Ya-Shin Yeh

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Limit Of Detection ◽

Point Of Care ◽

Low Cost ◽

Serum Samples ◽

Analytical Instruments ◽

Buffer Solutions ◽

Early Cancer Diagnosis

A graphene and poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) modified conductive paper-based electrochemical impedance spectroscopy (EIS) aptasensor has been successfully fabricated by a simple and continuous coating process. A graphene/PEDOT:PSS modified paper electrode forms the nanocomposite providing a conductive and sensitive substrate for further aptamer functionalization of the biosensor. This low-cost paper-based aptasensor exhibits its sensitivity to carcinoembryonic antigens (CEA) in standard buffer solutions and human serum samples in a linear range of 0.77–14 ng·mL−1. The limit of detection (LOD) is found to be 0.45 ng·mL−1 and 1.06 ng·mL−1 for CEA in both samples, separately. This aptamer-based sensing device was also evaluated and received a good correlation with the immunoassay detection method. The proposed paper-based aptasensor has demonstrated its potential as a rapid simple point-of-care analytical platform for early cancer diagnosis in less developed areas where manufacturing facilities, analytical instruments, and trained specialists are limited.

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Electrochemical Immunosensor for the Quantification of S100B at Clinically Relevant Levels Using a Cysteamine Modified Surface

Sensors ◽

10.3390/s21061929 ◽

2021 ◽

Vol 21 (6) ◽

pp. 1929

Author(s):

Alexander Rodríguez ◽

Francisco Burgos-Flórez ◽

José D. Posada ◽

Eliana Cervera ◽

Valtencir Zucolotto ◽

...

Keyword(s):

Frequency Analysis ◽

Surface Characterization ◽

Electrochemical Impedance ◽

Limit Of Detection ◽

Neuronal Damage ◽

Charge Transfer Resistance ◽

Single Frequency ◽

Response Analysis ◽

Transfer Resistance ◽

Therapeutic Decisions

Neuronal damage secondary to traumatic brain injury (TBI) is a rapidly evolving condition, which requires therapeutic decisions based on the timely identification of clinical deterioration. Changes in S100B biomarker levels are associated with TBI severity and patient outcome. The S100B quantification is often difficult since standard immunoassays are time-consuming, costly, and require extensive expertise. A zero-length cross-linking approach on a cysteamine self-assembled monolayer (SAM) was performed to immobilize anti-S100B monoclonal antibodies onto both planar (AuEs) and interdigitated (AuIDEs) gold electrodes via carbonyl-bond. Surface characterization was performed by atomic force microscopy (AFM) and specular-reflectance FTIR for each functionalization step. Biosensor response was studied using the change in charge-transfer resistance (Rct) from electrochemical impedance spectroscopy (EIS) in potassium ferrocyanide, with [S100B] ranging 10–1000 pg/mL. A single-frequency analysis for capacitances was also performed in AuIDEs. Full factorial designs were applied to assess biosensor sensitivity, specificity, and limit-of-detection (LOD). Higher Rct values were found with increased S100B concentration in both platforms. LODs were 18 pg/mL(AuES) and 6 pg/mL(AuIDEs). AuIDEs provide a simpler manufacturing protocol, with reduced fabrication time and possibly costs, simpler electrochemical response analysis, and could be used for single-frequency analysis for monitoring capacitance changes related to S100B levels.

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Circulating Tumor Cells from Enumeration to Analysis: Current Challenges and Future Opportunities

Cancers ◽

10.3390/cancers13112723 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2723

Author(s):

Yu-Ping Yang ◽

Teresa M. Giret ◽

Richard J. Cote

Keyword(s):

Tumor Cells ◽

Circulating Tumor Cells ◽

Ex Vivo ◽

Detection Sensitivity ◽

Clinical Utilization ◽

Diagnosis And Prognosis ◽

Early Cancer Diagnosis ◽

Potential Marker ◽

Potential Applications ◽

Downstream Analysis

Circulating tumor cells (CTCs) have been recognized as a major contributor to distant metastasis. Their unique role as metastatic seeds renders them a potential marker in the circulation for early cancer diagnosis and prognosis as well as monitoring of therapeutic response. In the past decade, researchers mainly focused on the development of isolation techniques for improving the recovery rate and purity of CTCs. These developed techniques have significantly increased the detection sensitivity and enumeration accuracy of CTCs. Currently, significant efforts have been made toward comprehensive molecular characterization, ex vivo expansion of CTCs, and understanding the interactions between CTCs and their associated cells (e.g., immune cells and stromal cells) in the circulation. In this review, we briefly summarize existing CTC isolation technologies and specifically focus on advances in downstream analysis of CTCs and their potential applications in precision medicine. We also discuss the current challenges and future opportunities in their clinical utilization.

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Supramolecular assemblies of carbon nanocoils and tetraphenylporphyrin derivatives for sensing of catechol and hydroquinone in aqueous solution

Scientific Reports ◽

10.1038/s41598-021-84294-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Syeda Aqsa Batool Bukhari ◽

Habib Nasir ◽

Lujun Pan ◽

Mehroz Tasawar ◽

Manzar Sohail ◽

...

Keyword(s):

Electrochemical Impedance ◽

Limit Of Detection ◽

Linear Trend ◽

Differential Pulse ◽

Peak Potential ◽

Limit Of Quantification ◽

Efficient Detection ◽

Good Repeatability ◽

Ft Ir ◽

Pulse Voltammetry

AbstractNon-enzymatic electrochemical detection of catechol (CC) and hydroquinone (HQ), the xenobiotic pollutants, was carried out at the surface of novel carbon nanocoils/zinc-tetraphenylporphyrin (CNCs/Zn-TPP) nanocomposite supported on glassy carbon electrode. The synergistic effect of chemoresponsive activity of Zn-TPP and a large surface area and electron transfer ability of CNCs lead to efficient detection of CC and HQ. The nanocomposite was characterized by using FT-IR, UV/vis. spectrophotometer, SEM and energy dispersive X-ray spectroscopy (EDS). Cyclic voltammetry, differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy were used for the electrochemical studies. CNCs/Zn-TPP/GCE nanosensor displayed a limit of detection (LOD), limit of quantification (LOQ) and sensitivity for catechol as 0.9 µM, 3.1 µM and 0.48 µA µM−1 cm−2, respectively in a concentration range of 25–1500 µM. Similarly, a linear trend in the concentration of hydroquinone detection was observed between 25 and 1500 µM with an LOD, LOQ and sensitivity of 1.5 µM, 5.1 µM and 0.35 µA µM−1 cm−2, respectively. DPV of binary mixture pictured well resolved peaks with anodic peak potential difference, ∆Epa(CC-HQ), of 110 mV showing efficient sensing of CC and HQ. The developed nanosensor exhibits stability for up to 30 days, better selectivity and good repeatability for eight measurements (4.5% for CC and 5.4% for HQ).

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A Novel Microfluidic Chip for Fast, Sensitive Quantification of Plasma Extracellular Vesicles as Biomarkers in Patients With Osteosarcoma

Frontiers in Oncology ◽

10.3389/fonc.2021.709255 ◽

2021 ◽

Vol 11 ◽

Author(s):

Yi-Qi Xu ◽

Qi-Yuan Bao ◽

Sai-Xi Yu ◽

Qi Liu ◽

Yan Xie ◽

...

Keyword(s):

Microfluidic Chip ◽

Limit Of Detection ◽

Zno Nanorods ◽

Extracellular Vesicle ◽

Fluorescent Labeling ◽

Total Plasma ◽

Sarcoma Cell ◽

Diagnosis And Prognosis ◽

Healthy Donors ◽

Capture Antibody

Plasma circulating extracellular vesicle (EV) has emerged as a promising biomarker for diagnosis and prognosis of various epithelial tumors. However, fast and efficient capture of EVs with microfluidic chip in sarcoma remains to be established. Herein, we reported a ZnO-nanorods integrated (ZNI) microfluidic chip, where EV capture antibody was uniformly grafted to the surface of the ZnO-nanorods of the chip to enhance the plasma turbulence formation and the capture efficiency at the micro-scale. Based on osteosarcoma (OS) cell line, we demonstrated that a combination of CD81 and CD63 antibody on ZNI chip yielded the greatest amount of total EVs, with an extra sensitive limit of detection (LOD) of ~104 particles mL-1. Furthermore, the addition of fluorescent labeling of Vimentin (VIM), a previously reported sarcoma cell surface biomarker, could enabled the dual visualization of total plasma EVs and VIM-positive EVs from OS patients’ plasma. Based on our ZNI chip, we found that the amount of plasma total EVs was significantly different between OS and healthy donors (1562 a.u. versus 639 a.u., p< 0.05), but not between metastatic and nonmetastatic OS (p> 0.05). Interestingly, patients with metastatic disease had a significantly greater amount of VIM-positive EVs (1411 a.u. versus 231 a.u.., p< 0.05) and increased VIM-positive/total EVs ratio (0.943 versus 0.211, p< 0.05) in comparison with the nonmetastatic counterpart. Therefore, our ZNI microfluidic chip has great potential for the fast quantification of plasma EVs, and the microfluidic-based quantification of total and VIM-positive EVs might serve as a promising biomarker for the diagnosis and surveillance in OS patients.

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An Electrochemical Sensor Based On Graphite Electrode Modified With Silica Containing 1-N-Propyl-3-Methylimidazolium Species For Determination Of Ascorbic Acid

METHODS AND OBJECTS OF CHEMICAL ANALYSIS ◽

10.17721/moca.2019.5-14 ◽

2019 ◽

Vol Vol. 14, No.1 ◽

pp. 5-14 ◽

Cited By ~ 1

Author(s):

Anastasiya Tkachenko ◽

Mykyta Onizhuk ◽

Oleg Tkachenko ◽

Leliz T. Arenas ◽

Edilson V. Benvenutt ◽

...

Keyword(s):

Ascorbic Acid ◽

Cyclic Voltammetry ◽

Electrochemical Sensor ◽

Electrochemical Impedance ◽

Limit Of Detection ◽

Pharmaceutical Formulations ◽

Differential Pulse ◽

Long Term Stability ◽

Diffusion Limited

In the present study, an electrochemical sensor based on the electrode (SiMImCl/C) consisting of graphite and silica, grafted with 1-n-propyl-3-methylimidazolium chloride was used for ascorbic acid (AA) quantification in pharmaceuticals and food formulations. Cyclic voltammetry and electrochemical impedance spectroscopy were applied for electrochemical characterization of the SiMImCl/C electrode. The cyclic voltammetry study revealed that the oxidation of AA on this electrode is an irreversible process, realized by adsorption and diffusion limited step. The differential pulse voltammetry was applied to develop a procedure for the AA determination. The linear range was found to be 0.3–170 μmol L-1 and the limit of detection – 0.1 μmol L-1. The proposed SiMImCl/C electrode has long term stability and does not show electrochemical activity towards the analytes, which commonly coexist with AA. The sensor was successfully used for quantification of AA in food and pharmaceutical formulations.

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