Development of electrochemical immunosensors towards point of care diagnostics

Wan, Ying; Su, Yan; Zhu, Xiangwei; Liu, Gang; Fan, Chunhai

doi:10.1016/j.bios.2013.02.045

Cited by 216 publications

(119 citation statements)

References 130 publications

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“…Such approaches bypass the need for qualified operators [11]. Furthermore, electrochemical devices are easily coupled with separation systems to make determinations in complex samples [12].…”

Section: Introductionmentioning

confidence: 99%

An integrated platform for gas-diffusion separation and electrochemical determination of ethanol on fermentation broths

Giordano

Vieira

Gobbi

et al. 2015

Analytica Chimica Acta

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Section: Introductionmentioning

confidence: 99%

An integrated platform for gas-diffusion separation and electrochemical determination of ethanol on fermentation broths

Giordano

Vieira

Gobbi

et al. 2015

Analytica Chimica Acta

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“…Screen-printed electrodes have been shown to be ideal for developing point-of-care assays due to their low cost, disposability and design exibility as compared to traditional electrode materials. [20][21][22] While various assays have been shown to integrate SPE-Au into electrochemical biosensors, 23 its application in DNA methylation detection has yet to be demonstrated.…”

Section: Introductionmentioning

confidence: 99%

eMethylsorb: rapid quantification of DNA methylation in cancer cells on screen-printed gold electrodes

Koo

Sina

Carrascosa

et al. 2014

Analyst

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Simple, sensitive and inexpensive regional DNA methylation detection methodologies are imperative for routine patient diagnostics. Herein, we describe eMethylsorb, an electrochemical assay for quantitative detection of regional DNA methylation on a single-use and cost-effective screen-printed gold electrode (SPE-Au) platform. The eMethylsorb approach is based on the inherent differential adsorption affinity of DNA bases to gold (i.e. adenine > cytosine $ guanine > thymine). Through bisulfite modification and asymmetric PCR of DNA, methylated and unmethylated DNA in the sample becomes guanine-enriched and adenine-enriched respectively. Under optimized conditions, adenine-enriched unmethylated DNA (higher affinity to gold) adsorbs more onto the SPE-Au surface than methylated DNA. Higher DNA adsorption causes stronger coulombic repulsion and hinders reduction of ferricyanide [Fe(CN) 6 ] 3À ions on the SPE-Au surface to give a lower electrochemical response. Hence, the response level is directly proportional to the methylation level in the sample. The applicability of this methodology was tested by detecting the regional methylation status in a cluster of eight CpG sites within the engrailed (EN1) gene promoter of the MCF7 breast cancer cell line. A 10% methylation level sensitivity with good reproducibility (RSD ¼ 5.8%, n ¼ 3) was achieved rapidly in 10 min. Furthermore, eMethylsorb also has advantages over current methylation assays such as being inexpensive, rapid and does not require any electrode surface modification. We thus believe that the eMethylsorb assay could potentially be a rapid and accurate diagnostic assay for point-of-care DNA methylation analysis.

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“…Next, monoclonal anti-H7 HA antibody (Ab 1 ) (8 μL, 30 μg·mL −1 ) was incubated for 12 h at 4°C and immobilized through Protein A' s affinity towards the F c region of antibodies. Because protein A specifically binds the F c region and the F ab region (antigenbinding) is orientated away from the electrode surface, resulting in efficient antigen-antibody binding [32]. To block the remaining empty sites, 8 μL of 0.25 % BSA solution was placed onto the electrode over 30 min at RT, and thoroughly cleaned with phosphate buffer (pH 7.0, 0.01 M).…”

Section: Fabrication Of the Electrochemical Immunosensormentioning

confidence: 99%

Quadruple signal amplification strategy based on hybridization chain reaction and an immunoelectrode modified with graphene sheets, a hemin/G-quadruplex DNAzyme concatamer, and alcohol dehydrogenase: ultrasensitive determination of influenza virus subtype H7N9

et al. 2015

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We report on a new amplification strategy for use in an immunoassay for influenza virus subtype H7N9. Graphene sheets were first placed on a glassy carbon electrode (GCE), and gold nanoparticles were then electrodeposited as a support for a layer of alcohol dehydrogenase (ADH) in a sol-gel containing thiol groups. Protein A was used to properly orientate immobilized antibody against H7N9 on the sol-gel, and this is shown to result in strongly improved specificity of the antigen-antibody binding. Thus, a sensitive and specific immunosensor was obtained in which a quadruple signal amplification strategy is employed, viz. (a) via the use of graphene sheets, (b) via a hybridization chain reaction, (c) the use of hemin/G-quadruplex DNAzyme concatamers, and (d) the use of ADH. The hemin/G-quadruplex is a typical DNAzyme, which simultaneously acts as NADH oxidase and HRP-mimicking DNAzyme. The hybridization chain reaction-based DNAzyme concatamers assembled on multiwalled carbon nanotubes (MWCNTs) and the ADH represent a triple electrocatalytic enzyme cascade system. Sandwich immunoreactions occurred between the capture antibody on the electrode and the secondary antibody labeled with MWCNTs. Positively charged Methylene Blue (MB) was then used as an intercalator to detect the DNAzyme concatamer formed. The differential pulse voltammetric signals for MB are related to the concentration of H7N9 in the range from 8 to 60 pg·mL −1 , and the detection limit is 0.81 pg·mL −1 (at an S/N ratio of 3). This immunoassay is very sensitive, specific and robust.

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Development of electrochemical immunosensors towards point of care diagnostics

Cited by 216 publications

References 130 publications

An integrated platform for gas-diffusion separation and electrochemical determination of ethanol on fermentation broths

An integrated platform for gas-diffusion separation and electrochemical determination of ethanol on fermentation broths

eMethylsorb: rapid quantification of DNA methylation in cancer cells on screen-printed gold electrodes

Quadruple signal amplification strategy based on hybridization chain reaction and an immunoelectrode modified with graphene sheets, a hemin/G-quadruplex DNAzyme concatamer, and alcohol dehydrogenase: ultrasensitive determination of influenza virus subtype H7N9

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