Diagnosis of dengue infection using a modified gold electrode with hybrid organic–inorganic nanocomposite and Bauhinia monandra lectin

Abstract

A sensitive and selective biosensor for dengue serotyping was successfully developed. The biosensor uses a novel gold nanoparticles-polyaniline hybrid composite (AuNpPANI) for the immobilization of Bauhinia monandra lectin (BmoLL). The nanocomposite was applied to a bare gold electrode surface by chemical adsorption, and BmoLL was subsequently electrostatically adsorbed to the nanocomposite-modified surface. Atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance (EI) techniques were applied to evaluate the immobilization of BmoLL on AuNpPANI. The AFM images for AuNpPANI-BmoLL-DEN systems indicate a homogenous, compact and dense film of the conjugate. In the EI analyses, an obvious difference of the electron transfer resistance between the AuNpPANI-modified electrode and the bare gold electrode was observed. Among three dengue serotypes studied, dengue serotype 2 (DEN2) has higher values for R(CT), and lower values for both n and Q. These are indications of a larger blocking effect and smaller capacitive dispersion, resulting from the higher agglutination of glycoproteins from the DEN2 sera. The selective BmoLL recognition for various dengue serotypes may be attributed to different patterns of glycoproteins in the sera produced by the glycoprotein immunoresponse from patients infected by the dengue virus.

A Highly Sensitive Impedimetric DNA Biosensor Based on Hollow Silica Microspheres for Label-Free Determination of E. coli

“…The ionic concentration and strength in the buffer solution are crucial, and they impact the solution resistance [34]. Measurement of buffer solution resistance is not influenced by surface electrode modification [16,35]. Optimization of the measurement buffer solution is focused on several important parameters, such as the type and concentration of the buffer solution, and the effect of salt concentration on the measurement buffer solution.…”

“…Aminated hollow silica microspheres (HSM) are used as the matrix for immobilization of probe DNA. According to Andrade et al [35], the R CT value depends on the insulation properties of the electrode-electrolyte interface. The considerable change of the R CT value compared to other impedance components makes R CT value an appropriate signal to detect the provided biosystem interface properties.…”

Square-wave voltammetry assays for glycoproteins on nanoporous gold

“…The amount of nanoparticles attached to lectin was determined by dissolution followed by stripping analysis [44]. Gold nanoparticles modified with Con A and immobilized in polyvinyl butyral were found to exhibit a response, as determined by EIS, to the sera of patients infected with dengue fever or dengue hemorrhagic fever [45]. Serotypes of dengue fever were distinguished using this detection scheme with Cratylia morris (CramoLL) lectin immobilized on iron oxide nanoparticles within the polymer film on a gold electrode.…”

Recent Progress in Electrochemical Biosensors for Glycoproteins

“…The sensors show higher responses to dengue serotype 2 than to serotypes 1 and 3. Another group has also reported impedimetric sensors sensitive to dengue serotype 2 [91]. They used PANI/Au nanoparticle composites with electrostatically attached BmoLL lectin.…”