No abstract

Despite significant advances in medicine, global health is threatened by emerging infectious diseases caused by a number of viruses. Dengue virus (DENV) is a mosquito-borne virus, which can be transmitted to humans via mosquito vectors. Previously, the Ministry of Health, Labour and Welfare in Japan reported the country's first domestically acquired case of dengue fever for almost 70 years. To address this issue, it is important to develop novel technologies for the sensitive detection of DENV. The present study reported on the development of plasma-functionalized, graphite-encapsulated magnetic nanoparticles (GrMNPs) conjugated with anti-DENV antibody for DENV capture. Radiofrequency wave-excited inductively-coupled Ar and ammonia gas plasmas were used to introduce amino groups onto the surface of the GrMNPs. The GrMNPs were then conjugated with an antibody against DENV, and the antibody-integrated magnetic beads were assessed for their ability to capture DENV. Beads incubated in a cell culture medium of DENV-infected mosquito cells were separated from the supernatant by applying a magnetic field and were then washed. The adsorption of DENV serotypes 1–4 onto the beads was confirmed using reverse transcription-polymerase chain reaction, which detected the presence of DENV genomic RNA on the GrMNPs. The methodology described in the present study, which employed the plasma-functionalization of GrMNPs to enable antibody-integration, represents a significant improvement in the detection of DENV.

No abstract

The bioconjugation efficiency of carbon-encapsulated iron nanoparticles (Fe@C NPs) with a typical diameter of 20-40 nm functionalized by plasma was studied, aiming at their applications to highlysensitive virus detection system. The Fe@C NPs were functionalized with amino group, and the population of amino groups on the nanoparticles was varied by changing the plasma operating conditions. Radio frequency wave-excited inductively-coupled Ar and ammonia gas plasmas were used to introduce amino groups onto the surface of Fe@C NPs. The efficiency in bioconjugation was examined with biotin-avidin system. Initially the amino modified Fe@C NPs were immobilized with biotins, and then the interaction of it with the avidin molecules was analyzed using absorption and fluorescence spectroscopy techniques. From the results of these studies, it was found that the plasma functionalized Fe@C NP indicated a highly-efficient bioconjugation property using biotin-avidin system. Furthermore, the present results suggest a feasibility of highly-sensitive virus capturing system using the plasma-functionalized Fe@C NPs.

The authors regret that the printed version of the above article contained a number of errors in calculating the numbers of amino groups per nanoparticle. The corrected versions of figures 3(a), 5, 6 and 9 are given, along with corrections of some incorrect values and sentences. This error affects only the detailed number of amino groups per nanoparticle, not the discussion or interpretation of the results.