Constructing a novel composite of molecularly imprinted polymer-coated AuNPs electrochemical sensor for the determination of 3-nitrotyrosine

A sensitive and highly selective imprinted sensor for detecting an oxidative stress biomarker 3-nitrotyrosine (3-NT) detection was developed based on electropolymerized pyrrole molecularly imprinted polymer (MIP) doped with gold nanoparticles (AuNPs) on a glassy carbon electrode (GCE) modified with activated multiwall carbon nanotube @ graphene oxide nanoribbons (AMWCNT@GONRs). Adding AuNPs into the polymer composite effectively generated electrical response by facilitating the charge transfer process. As the specific recognition sites, the fabricating imprinted polymer-AMWCNT@GONRs composite exhibited excellent sensitivity, stability and specific selectivity behavior towards 3-NT. The surfaces morphology of the MIP modified electrode was characterized by scanning electron microscopy (SEM) showing that AMWCNT@GONRs were well dispersed under the imprinted polymer owning to highly porous surface structure. Under optimal conditions, the determination range of imprinted sensor for 3-NT was linearly response from 0.2 to 50.0 μM with a detection limit (S/N = 3) of 50.0 nM. Furthermore, this modified MIP sensor was successfully used for detection of 3-NT in human serum and urine samples.