Bioconjugation efficiency of plasma-functionalized carbon-encapsulated iron nanoparticles with biotin–avidin system

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 highly-sensitive 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.