title: An amperometric biosensor based on laccase immobilized onto MnO2NPs/cMWCNT/PANI modified Au electrode.
abstract: A method is described for construction of an amperometric biosensor for detection of phenolic compounds based on covalent immobilization of laccase (Lac) onto manganese dioxide nanoparticles (MnO(2)NPs) decorated carboxylated multiwalled carbon nanotubes (cMWCNTs)/PANI composite electrodeposited onto a gold (Au) electrode through N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS) chemistry. The modified electrode was characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The biosensor showed optimum response at pH 5.5 (0.1M sodium acetate buffer) and 35°C, when operated at 0.3 V vs. Ag/AgCl. Linear range, response time, detection limit were 0.1-10 μM (lower concentration range) and 10-500 μM (higher concentration range), 4s and 0.04 μM, respectively. Biosensor measured total phenolic content in tea leaves extract. The enzyme electrode was used 150 times over a period of 5 months.
authors.affiliation: Department of Biochemistry, MD University, Rohtak 124 001, Haryana, India.
authors.forename: Rachna
authors.initials: R
authors.lastname: Rawal
authors.forename: Sheetal
authors.initials: S
authors.lastname: Chawla
authors.forename: Poonam
authors.initials: P
authors.lastname: Malik
authors.forename: C S
authors.initials: CS
authors.lastname: Pundir
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006139:Guaiacol / Q000737:chemistry; D042845:Laccase / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D006139:Guaiacol; D042845:Laccase