Rapid and highly sensitive detection of Enterovirus 71 by using nanogold-enhanced electrochemical impedance spectroscopy

Abstract

Enterovirus 71 (EV71) infection is an emerging infectious disease causing neurological complications and/or death within two to three days after the development of fever and rash. A low viral titre in clinical specimens makes the detection of EV71 difficult. Conventional approaches for detecting EV71 are time consuming, poorly sensitive, or complicated, and cannot be used effectively for clinical diagnosis. Furthermore, EV71 and Coxsackie virus A16 (CA16) may cross react in conventional assays. Therefore, a rapid, highly sensitive, specific, and user-friendly test is needed. We developed an EV71-specific nanogold-modified working electrode for electrochemical impedance spectroscopy in the detection of EV71. Our results show that EV71 can be distinguished from CA16, Herpes simplex virus, and lysozyme, with the modified nanogold electrode being able to detect EV71 in concentrations as low as 1 copy number/50 μl reaction volume, and the duration between sample preparation and detection being 11 min. This detection platform may have the potential for use in point-of-care diagnostics.

Gold Nanostructured Surface for Electrochemical Sensing and Biosensing: Does Shape Matter?

“…where Q0 is the capacitance, j is the imaginary unit,  is the angular frequency, and n is a number between 0 and 1 (Li et al 2013). When n = 1; Q is an ideal capacitor; when n = 0; Q is a pure resistor.…”

“…Among the metals, gold attracts special attention for sensing due to its excellent optical and electrical properties and affinity to bind with biomolecules (Li et al 2013;Ravalli et al 2013;Lv et al 2014). In the formation of nanostructure arrays, gold is used to modify the electrodes of electrochemical biosensors which enhances the active surface area and thus the sensitivity.…”

A regenerating ultrasensitive electrochemical impedance immunosensor for the detection of adenovirus

“…In order to address some of these issues, we recently utilized an electrochemical reductive desorption technique to repeatedly desorb and reconstruct a gold nanoparticle-loaded self-assembled monolayer (SAM) sensor surface for electrochemical impedance spectroscopy (EIS) detection of oligonucleotides (Mahmoud et al, 2014). EIS biosensors are typically constructed using either SAMs or electrodeposited conducting polymer base-layers to immobilize the bioactive material (antibody, antigen, DNA) on the surface of the electrode (Amano and Cheng, 2005;Caygill et al, 2012;Fang et al, 2010;Hejazi et al, 2010;Jarocka et al, 2014;Jiang and Spencer, 2010;Li et al, 2013;Park et al, 2010;Tang et al, 2004;Cui and Martin, 2003). The long term stability of both approaches has been problematic (Cui and Martin, 2003;Cometto et al, 2012;Cooper and Legget, 1998;Lee et al, 2004;Nishida et al, 1996;Schoenfisch and Pemberton, 1998;Shadnam and Amirfazli, 2005;Yan et al, 2006), as is regeneration of the antibody.…”

“…The impedimetric sensor presented here is based on anti-Ad5 covalently bound to gold nanoparticles (Au NPs), self-assembled on a Au electrode loaded with 1,6-hexanedithiol. Recently, construction of EIS biosensors using Au NPs to improve performance has received significant attention (Li et al, 2013;Liu et al, 2011;Bradbury et al, 2008;Zhao et al, 2008;Zhang et al, 2007;Gooding et al, 2014), exploring amplification methods, immunoassays and mechanism. However, reports of EIS using Au NPs for viral particles immunosensing are scarce (Li et al, 2013).…”

“…Recently, construction of EIS biosensors using Au NPs to improve performance has received significant attention (Li et al, 2013;Liu et al, 2011;Bradbury et al, 2008;Zhao et al, 2008;Zhang et al, 2007;Gooding et al, 2014), exploring amplification methods, immunoassays and mechanism. However, reports of EIS using Au NPs for viral particles immunosensing are scarce (Li et al, 2013). The developed sensor is highly sensitive, allowing for the detection of 30 Ad5 particles/ml, and it can be repeatedly regenerated in situ by electrochemical reductive desorption, and thiol self-assembly techniques.…”