Sandwich-Structured Nanoparticles-Grafted Functionalized Graphene Based 3D Nanocomposites for High-Performance Biosensors to Detect Ascorbic Acid Biomolecule Publisher Pubmed



Salahandish R^{1, 2, 3, 4} ; Ghaffarinejad A^{1, 2} ; Naghib SM⁵ ; Niyazi A⁵ ; Majidzadeha K⁶ ; Janmaleki M^{3, 4} ; Sanatinezhad A^{3, 4}
Source: Scientific Reports Published:2019

Abstract

We present a highly sensitive and selective nano-biosensor for rapid, stable and highly reproducible detection of ascorbic acid (AA) in the presence of dopamine, uric acid and other interferences by a three-layer sandwich arrangement of nitrogen-doped functionalized graphene (NFG), silver nanoparticles (AgNPs) and nanostructured polyaniline (PANI) nanocomposite. The enhanced AA electrochemical properties of the NFG/AgNPs/PANI electrode is attributed to the superior conductivity of the NFG-PANI and the excellent catalytic activity of AgNPs. The critical modification of the AgNPs-grafted NFG-PANI coated on very low-cost fluorine doped tin oxide electrode (FTOE) increased the charge transfer conductivity of the electrode (the resistance drops down from 11,000 Ω to 6 Ω). The nano-biosensor was used to accurately detect AA in vitamin C tablets with the recovery of 98%. The sensor demonstrated a low detection limit of 8 µM (S/N = 3) with a very wide linear detection range of 10–11,460 µM, good reproducibility and excellent selectivity performance for AA detection. The results demonstrate that this nanocomposite is a promising candidate for rapid and selective detection of AA in practical clinical samples. © 2019, The Author(s).