title: Highly sensitive amperometric biosensor based on electrochemically-reduced graphene oxide-chitosan/hemoglobin nanocomposite for nitromethane determination.
abstract: Nitromethane (CH3NO2) is an important organic chemical raw material with a wide variety of applications as well as one of the most common pollutants. Therefore it is pretty important to establish a simple and sensitive detection method for CH3NO2. In our study, a novel amperometric biosensor for nitromethane (CH3NO2) based on immobilization of electrochemically-reduced graphene oxide (rGO), chitosan (CS) and hemoglobin (Hb) on a glassy carbon electrode (GCE) was constructed. Scanning electron microscopy, infrared spectroscopy and electrochemical methods were used to characterize the Hb-CS/rGO-CS composite film. The effects of scan rate and pH of phosphate buffer on the biosensor have been studied in detail and optimized. Due to the graphene and chitosan nanocomposite, the developed biosensor demonstrating direct electrochemistry with faster electron-transfer rate (6.48s(-1)) and excellent catalytic activity towards CH3NO2. Under optimal conditions, the proposed biosensor exhibited fast amperometric response (<5s) to CH3NO2 with a wide linear range of 5 μM~1.46 mM (R=0.999) and a low detection limit of 1.5 μM (S/N=3). In addition, the biosensor had high selectivity, reproducibility and stability, providing the possibility for monitoring CH3NO2 in complex real samples.
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China.
authors.forename: Yunping
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China. Electronic address: wenwei@hubu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Wen
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China.
authors.forename: Xiuhua
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China. Electronic address: wangsf@hubu.edu.cn.
authors.forename: Shengfu
authors.initials: S
authors.lastname: Wang
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D048271:Chitosan / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods; D006108:Graphite / Q000737:chemistry*; D006454:Hemoglobins / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000032:analysis; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D009595:Nitroparaffins / Q000032:analysis*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D006454:Hemoglobins; D009595:Nitroparaffins; D010087:Oxides; D006108:Graphite; D048271:Chitosan; D008697:Methane; C008640:nitromethane
keywords: Direct electrochemistry; Electrochemical biosensor; Electrochemically-reduced graphene oxide; Graphene-chitosan/hemoglobin nanocomposite; Nitromethane