Core-shell heterostructured multiwalled carbon nanotubes@reduced graphene oxide nanoribbons/chitosan, a robust nanobiocomposite for enzymatic biosensing of hydrogen peroxide and nitrite

Veerappan Mani,Mani Govindasamy,Shen-Ming Chen,Tse-Wei Chen,Annamalai Senthil Kumar,Sheng-Tung Huang

doi:10.1038/s41598-017-12050-x

Abstract

A robust nanobiocomposite based on core-shell heterostructured multiwalled carbon nanotubes@reduced graphene oxide nanoribbons (MWCNTs@rGONRs)/chitosan (CHIT) was described for the fabrication of sensitive, selective, reproducible and durable biosensor for hydrogen peroxide (H2O2) and nitrite (NO2−). The excellent physicochemical properties of MWCNTs@rGONRs such as, presence of abundant oxygen functionalities, higher area-normalized edge-plane structures and chemically active sites in combination with excellent biocompatibility of CHIT resulting in the versatile immobilization matrix for myoglobin (Mb). The most attractive property of MWCNTs@rGONRs which distinguishes it from other members of graphene family is its rich edge density and edge defects that are highly beneficial for constructing enzymatic biosensors. The direct electron transfer characteristics such as, redox properties, amount of immobilized active Mb, electron transfer efficiency and durability were studied. Being as good immobilization matrix, MWCNTs@rGONRs/CHIT is also an excellent signal amplifier which helped in achieving low detection limits to quantify H2O2 (1 nM) and NO2− (10 nM). The practical feasibility of the biosensor was successfully validated in contact lens cleaning solution and meat sample.

Highlights

Meeting the demand for cost-effective, robust and portable analytical devices, enzymatic biosensors have enormous potential as useful sensing tools in medicine, biofuel cells, food control, and in biomedical analysis[1,2]
We described a biocompatible nanobiocomposite based on chitosan (CHIT) encapsulated MWCNTs@rGONRs for the immobilization of myoglobin (Mb) and developed a sensitive biosensor for hydrogen peroxide (H2O2) and nitrite (NO2−)
Being as good immobilization matrix for Mb, our study revealed that MWCNTs@rGONRs/CHIT is an excellent signal amplifier for the detections of H2O2 and NO2−

Summary

Introduction

Meeting the demand for cost-effective, robust and portable analytical devices, enzymatic biosensors have enormous potential as useful sensing tools in medicine, biofuel cells, food control, and in biomedical analysis[1,2]. Nanocomposites composed of carbonaceous nanomaterials (multiwalled carbon nanotubes (MWCNTs), graphene oxide (GO), graphene etc.,) and biopolymers are good immobilization matrix and they can enhance the signal sensitivity as well attributed to their outstanding electronic properties[6,7]. The core-shell heterostructured multiwalled carbon nanotubes@reduced graphene oxide nanoribbons (MWCNTs@rGONRs), a narrow strips of GO nanosheets can be prepared through longitudinal unzipping of MWCNTs and possess good physicochemical properties which includes large surface area, high conductivity, presence of abundant oxygen functionalities, available sites for covalent and non-covalent (π stacking) interactions[10], good biocompatibility, chemical stability, and excellent mechanical, and thermal properties[11,12,13]. We described a biocompatible nanobiocomposite based on chitosan (CHIT) encapsulated MWCNTs@rGONRs for the immobilization of myoglobin (Mb) and developed a sensitive biosensor for hydrogen peroxide (H2O2) and nitrite (NO2−). The main objective of this work is to develop a nanobiocomposite for Mb immobilization and a sensitive, reproducible, selective, and durable biosensor for H2O2 and NO2−

Objectives

Results

Conclusion