title: A novel amperometric biosensor for superoxide anion based on superoxide dismutase immobilized on gold nanoparticle-chitosan-ionic liquid biocomposite film.
abstract: A novel superoxide anion (O(2)(-)) biosensor is proposed based on the immobilization of copper-zinc superoxide dismutase (SOD) in a gold nanoparticle-chitosan-ionic liquid (GNPs-CS-IL) biocomposite film. The SOD-based biosensor was constructed by one-step ultrasonic electrodeposition of GNP-CS-IL composite onto glassy carbon electrode (GCE), followed by immobilization of SOD on the modified electrode. Surface morphologies of a set of representative films were characterized by scanning electron microscopy. The electrochemical performance of the biosensor was evaluated by cyclic voltammetry and chronoamperometry. A pair of quasi-reversible redox peaks of SOD with a formal potential of 0.257V was observed at SOD/GNPs-CS-IL/GCE in phosphate buffer solution (PBS, 0.1M, pH 7.0). The effects of varying test conditions on the electrochemical behavior of the biosensor were investigated. Furthermore, several electrochemical parameters were calculated in detail. Based on the biomolecule recognition of the specific reactivity of SOD toward O(2)(-), the developed biosensor exhibited a fast amperometric response (<5s), wide linear range (5.6-2.7×10(3)nM), low detection limit (1.7nM), and excellent selectivity for the real-time measurement of O(2)(-). The proposed method is promising for estimating quantitatively the dynamic changes of O(2)(-) in biological systems.
authors.affiliation: 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: Lu
authors.initials: L
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Wen
authors.forename: Huayu
authors.initials: H
authors.lastname: Xiong
authors.forename: Xiuhua
authors.initials: X
authors.lastname: Zhang
authors.forename: Haoshuang
authors.initials: H
authors.lastname: Gu
authors.forename: Shengfu
authors.initials: S
authors.lastname: Wang
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D002417:Cattle; D048271:Chitosan / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D006046:Gold / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013482:Superoxide Dismutase / Q000737:chemistry / Q000378:metabolism*; D013481:Superoxides / Q000032:analysis* / Q000378:metabolism
chemical_list: D004800:Enzymes, Immobilized; D052578:Ionic Liquids; D013481:Superoxides; D006046:Gold; D048271:Chitosan; D013482:Superoxide Dismutase