Sandwich-structured nanoparticles-grafted functionalized graphene based 3D nanocomposites for high-performance biosensors to detect ascorbic acid biomolecule

Razieh Salahandish,Keivan Majidzadeh-A,Asghar Niyazi,Mohsen Janmaleki,Seyed Morteza Naghib,Amir Sanati-Nezhad,Ali Ghaffarinejad

doi:10.1038/s41598-018-37573-9

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.

Highlights

Ascorbic acid (AA) is an effective antioxidant and reducing agent, playing roles in precluding radical-induced disorders like neurodegenerative diseases and cancer[1]
The surface polymerization accumulated clusters of the PANI on the graphene surface and gradually formed the thin PANI film covering the entire surface of the graphene
The results show three different slopes for each of four nitrogen-doped functionalized graphene (NFG), PANI, NFG/PANI, and NFG/Ag/PANI electrodes which demonstrates the sensitivity of the sensor to both concentration and volume of ascorbic acid (AA) samples

Summary

Introduction

Ascorbic acid (AA) is an effective antioxidant and reducing agent, playing roles in precluding radical-induced disorders like neurodegenerative diseases and cancer[1]. A new electrochemical sensor is developed for very low cost, highly sensitive and selective detection of AA in a wide detection range by an optimized sandwich arrangement of grafted silver nanoparticles (AgNPs) and nanostructured polyaniline (PANI) nanocomposite on nitrogen-doped functionalized graphene (NFG) electrode (Fig. 1).

Results

Conclusion