A dual marker label free electrochemical assay for Flavivirus dengue diagnosis

Abstract

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).

Ultrasensitive detection of pathogenic viruses with electrochemical biosensor: State of the art

“…100 Hz optimized frequency was found, and the target-responsive data is shown in Fig. 2 E ( Santos et al, 2018 ). Nguyen et al used serotype 2 (Denv2) as an analyte in the EIS system and explored that resistance and capacitance are effective to detect Denv2.…”

“…2 (A–D) Schematic construction of the anti-NS1 and NS1 modified electrode surfaces, (E) Example of 1/C″ immittance function investigation for NS1 detection in PBS, the optimized frequency, 100 Hz, corresponds to the most sensitive response with R 2 > 0.96. Adapted from ( Santos et al, 2018 ). (F) Consecutive experimental steps using the same nano biosensor, investigated after 30 min incubations of CHIKV, WNV, and DENV-2 respectively.…”

Label-Free Electrochemical Biosensors for the Determination of Flaviviruses: Dengue, Zika, and Japanese Encephalitis

“…Typically, the obtained impedance spectra are fitted to an equivalent circuit using a Nyquist plot for illustration, and the change in charge transfer resistance is correlated to the target biological material concentration [62]. For the situation of an electrode in contact with an electrolyte, the so-called Randles circuit is used (Figure 1), comprising the double-layer capacitance C dl, the solution resistance R s , the charge transfer resistance R ct , and the Warburg impedance W. (measuring the conductivity or resistance) [44], amperometry/voltammetry (current measurement as a function of imposed potential) [28,[45][46][47], and EIS (measuring the impedance of a system) [48][49][50]. The majority of publications over the past decades focus on voltammetric and EIS techniques to obtain label-free biosensors with a high sensitivity and, therefore, low limit of detection (LOD), which are the main figures of merit of biosensors.…”

“…The majority of publications are devoted to registration of the resultant current of the redox probe corresponding to changing electrode potential. Ferri/ferrocyanide, ferrocene, ferrocenethanol systems, and ruthenium complexes are the most frequently used redox probes [50,69,70]. The electrochemical behavior of redox probes depends on the receptor layer and the biosensor operating principle.…”

Printed Electrodes in Microfluidic Arrays for Cancer Biomarker Protein Detection

“…Aptamers are oligonucleotide or protein recognition probes that are selected for binding a target molecule from a large random sequence pool. Davis’ group has done interesting work on EIS-based label-free immunoassays that have catalyzed progress in unlabeled immunoassays and can be adapted to printed electrodes [ 116 , 117 , 118 , 119 , 120 , 121 ].…”