Electrochemical fabrication of self assembled monolayer using ferrocene-functionalized gold nanoparticles on glassy carbon electrode

Electrochemical (EC) quantification of 11-Mercaptoundecylferrocene (thiolated-ferrocene substrate, Fc-SH) onto gold nanoparticles (AuNPs) was carried out through cyclic voltammetric (CV) investigations in different base electrolyte aqueous media on glassy carbon (GC) electrode. The electrochemical data including peak current, peak potential values revealed the Fc-SH–AuNPs redox system to be adsorption controlled in terms of self assembled monolayers (SAMs). The electrochemically generated SAMs were found quite stable as these maintained the redox activity upto 3 months after repeated CV scans at 298 K. The overall output of this research can be utilized in two ways: application of electroactivity and stability of these SAMs in detection of biologically important molecules and also towards the development of EC biosensors.

► The most important aspect of present study is that in all the base electrolytes, ferrocene moiety retained its redox activity (in its conjugated form onto AuNPs) which could be manipulated electrochemically.
► The gold nanoparticles were functionalized with electroactive ferrocene substrate with the help of thiolated PEG ligands.
► These anchored AuNPs were aqueous soluble and stable.
► The EC SAM formation by these Fc-SH–AuNPs redox systems could be characterized on GC electrode and resulting SAMs were responsive even after 3–4 months.
► The overall output of this research can be utilized in two ways: the application of electroactivity and stability of these SAMs in detection of biologically important molecules and possible candidateship towards the development of EC biosensors.