Electrochemical Immunoassay for Cytomegalovirus Antigen Detection with Multiple Signal Amplification Using HRP and Pt‐Pd Nanoparticles Functionalized Single‐walled Carbon Nanohorns

Abstract

Cytomegalovirus is typically associated with immunocompromised hosts, pregnant women and transplant patients, who require a timely diagnosis. In this work, a sensitive and highly specific electrochemical amplification immunosensor was established for detecting Cytomegalovirus pp65 antigen based on Pt‐PdNPs@SWCNHs with horseradish peroxidase (HRP) as a signal enhancer and thionine as a signal probe. First, Pt nanoparticle (PtNP) and Pd nanoparticle (PdNP) functionalized single‐walled carbon nanohorn (SWCNH) nanocomposites, i.e. Pt‐PdNPs@SWCNHs, was used as a carrier for immobilization of antibody through the Pt‐N bond and the Pd‐N bond. Next, HRP was used to block the rest of the binding‐sites. Signal amplification was obtained by the cooperative catalytic activities of Pt‐PdNPs and HRP to H2O2. SWCNHs loaded with a large amount of Pt‐PdNPs further amplified the signal due to the excellent surface area. The fabricated immunosensor was used to detect different concentrations of Cytomegalovirus pp65 antigen under optimized conditions. The tests showed a linear range from 0.1 to 80 ng mL−1 with a low detection limit of 30 pg mL−1, and exhibited excellent selectivity, stability and reproducibility. Therefore, this project presented a potential approach for the early diagnosis of Cytomegalovirus infection in clinical trials.

Nanomaterials for virus sensing and tracking

“…Owing to the unique structure of the electronic bands of graphene, it shows extraordinary thermal, electrical, and mechanical properties. [114][115][116][117] In recent years, other carbon allotropes such as nanohorns, 118 nanodiamonds, 119,120 and nanoparticles 121,122 have also been introduced into sensing and imaging technologies due to their superior fluorescence, impedance, and energy transfer capabilities. These qualities make carbon allotrope-based nanomaterials ideal for incorporation into biosensing and bioimaging platforms.…”

“…Such nanocomposites show promising durability with only 5.8% signal loss in 15 days for horseradish peroxidase-based immunosensing of cytomegalovirus which is often responsible for diseases such as pneumonia and mononucleosis. 118 Crystal defects such as vacancies as well as doping give rise to unique properties at the nanoscale. 177 Fig.…”

“…Such nanocomposites show promising durability with only 5.8% signal loss in 15 days for horseradish peroxidase-based immunosensing of cytomegalovirus which is often responsible for diseases such as pneumonia and mononucleosis. 118 Crystal defects such as vacancies as well as doping give rise to unique properties at the nanoscale. 177 Therefore, doping nanodiamonds with boron results in semiconducting behavior and electrodes developed from such materials can be conjugated with polyclonal antibodies to allow the rapid detection of influenza viral proteins 178 as well as whole virions.…”

Nanostructure-Based Electrochemical Immunosensors as Diagnostic Tools

“…Until 2010, not many electrochemical immunosensors based on CNHs were reported. During the last ten years, they have been employed both as electrode materials [76][77][78][79] and as electrocatalytic tracers/nanocarriers [40,80,81].…”

Microelectromechanical system‐based biosensor for label‐free detection of human cytomegalovirus

“…Pires et al [20] proposed a method to detect glycoprotein B of HCMV (gB-HCMV) in urine samples using magnetic particle-based enzyme immunoassay (mpEIA), with a detection limit of 30 pg/ml. Huang et al [21] reported an electrochemical amplification immunosensor for detecting the UL83antigen of cytomegalovirus using horseradish peroxidase attached to single-walled carbon nanohorns decorated by Pt and Pd nanoparticles with a detection limit of 30 pg/ml.…”