Label free redox capacitive biosensing

Fernandes, Flávio Cesar Bedatty; Góes, Márcio Sousa; Davis, Jason J.; Bueno, Paulo Roberto

doi:10.1016/j.bios.2013.06.043

Cited by 74 publications

(51 citation statements)

References 24 publications

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“…All measurements were performed at the E in potential (note that at E out the capacitance is unresponsive to target recognition). A decrease in redox capacitance signal (semicircle diameter) was observed, as expected (Fernandes et al, 2014(Fernandes et al, , 2013Santos et al, 2014). It is worth noting that the relative response RR as a function of target concentration (i.e.…”

Section: Ns1 Detection In Pbs and Diluted Serumsupporting

confidence: 76%

“…In the dominant faradaic approach, it is additionally necessary to pre-dope with an amplifying excess of redox probe (Lisdat and Schäfer, 2008) prior using the resolved charge transfer resistance (R ct ) as signal transduction. As an alternative, we have introduced the use of redox tagged receptor interfaces and redox capacitance (C r ) (from electrochemical impedance-derived capacitance spectroscopy) as underpinning a fully label free sensory approach (Fernandes et al, 2014(Fernandes et al, , 2013Santos and Bueno, 2016). Although this approach brings significant practical advantages, by default, it also requires a full spectrum analysis.…”

Section: Introductionmentioning

confidence: 99%

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A dual marker label free electrochemical assay for Flavivirus dengue diagnosis

Santos

Bueno

Davis

2018

Biosensors and Bioelectronics

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Dengue is a RNA viral illness of the genus Flavivirus which can cause, depending on the pervasiveness of the infection, hemorrhagic dengue fever or dengue shock syndrome. Herein we present an electrochemical label free approach enabling the rapid sensitive quantification of NS1 and IgG (supporting an ability to distinguish primary and secondary infections). Using a bifunctional SAM containing PEG moieties and a tethered redox thiol, both markers are detectable across clinically relevant levels by label free impedance derived redox capacitance. A subsequent frequency specific immittance function approach enables assaying (within seconds) with no impairment of analytical quality (linearity, sensitivity and variance).

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Section: Ns1 Detection In Pbs and Diluted Serumsupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

A dual marker label free electrochemical assay for Flavivirus dengue diagnosis

Santos

Bueno

Davis

2018

Biosensors and Bioelectronics

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“…When target binding events occur, there is a perturbation on the electrochemical activity associated with the C r signal, as illustrated in Fig. 1f, thus enabling sensitive analytical curves to be constructed using C r as an effective transduction signal (Fernandes et al, 2015(Fernandes et al, , 2013Lehr et al, 2014;Marques et al, 2015;Santos and Bueno, 2016;Santos et al, 2014Santos et al, , 2015aSantos et al, , 2015b. In other words, capacitive approach has the advantage of not requiring the redox probe pre-doping of the biological samples, making it particularly appealing for point-of-care applications (Patil et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

“…In other words, capacitive approach has the advantage of not requiring the redox probe pre-doping of the biological samples, making it particularly appealing for point-of-care applications (Patil et al, 2014). Hence the use of ECS in diagnostic assays has been effectively demonstrated within label-free standards and being highly specific to target biomarkers, presenting good reproducibility and high sensitivity (at nano to picomolar ranges) (Fernandes et al, 2015(Fernandes et al, , 2013Lehr et al, 2014;Marques et al, 2015;Santos and Bueno, 2016;Santos et al, 2014Santos et al, , 2015aSantos et al, , 2015b.…”

Section: Introductionmentioning

confidence: 99%

The capacitive sensing of NS1 Flavivirus biomarker

Cecchetto

Fernandes

Lopes

et al. 2017

Biosensors and Bioelectronics

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NS1 is a biomarker for different Flavivirus diseases such as dengue (DENV), zika (ZIKV) and chikungunya (CHIKV) and was herein selectively quantified by electrochemical capacitive sensing (an impedance-derived capacitance methodology wherein the redox probe is contained in the receptive layer) mainly aiming dengue diagnosis in phosphate buffer saline and blood serum environments (up to the neat level). The capacitive sensing was compared to traditional concurrent impedimetric approach (in which the redox probe is added in the biological solution) and other transient methods stated in the literature regarding figures of merit such as limit of detection, linear range, relative standard deviation and affinity constant. Capacitive and impedimetric assays showed equivalent results for linear range, repeatability, sensitivity and constant of affinity. Nonetheless capacitive assays presented better reproducibility with a relative standard deviation (RSD) of 3±1 and 7±4 (all in percentage) in PBS and serum, respectively, meanwhile for impedimetric assays the RSD values were 9±5 in PBS and 12±6 in serum. Thus, by using capacitive assays, an improvement on the analytical performance was observed with the limit of detection about sixty-fold lower in neat serum (∼0.5ngmL for capacitive over ∼30ngmL for impedimetric assays) compared to traditional electrochemistry methods in general hence demonstrating the superior detection sensitivity for NS1 protein. Accordingly, redox tagged capacitive assays are suitable for the development of multiplex point-of-care neglected diseases sensing applications.

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“…Such Fc-terminated SAM modified electrodes show a one-electron redox reaction: Fc ⇌ Fc + + e − . So far, many reports have been published on electron-transfer kinetics [5][6][7][8], electric double-layer effects [9,10], application as an electron mediator [11] and also biosensing [12][13][14]. In these studies, however, Fc moieties were usually exposed on the surface of SAM.…”

Section: Introductionmentioning

confidence: 99%