title: Detection of methyl salicylate using bi-enzyme electrochemical sensor consisting salicylate hydroxylase and tyrosinase.
abstract: Volatile organic compounds have been recognized as important marker chemicals to detect plant diseases caused by pathogens. Methyl salicylate has been identified as one of the most important volatile organic compounds released by plants during a biotic stress event such as fungal pathogen infection. Advanced detection of these marker chemicals could help in early identification of plant diseases and has huge significance for agricultural industry. This work describes the development of a novel bi-enzyme based electrochemical biosensor consisting of salicylate hydroxylase and tyrosinase enzymes immobilized on carbon nanotube modified electrodes. The amperometric detection using the bi-enzyme platform was realized through a series of cascade reactions that terminate in an electrochemical reduction reaction. Electrochemical measurements revealed that the sensitivity of the bi-enzyme sensor was 30.6±2.7µAcm(-2)µM(-1) and the limit of detection and limit of quantification were 13nM (1.80ppb) and 39nM (5.39ppb) respectively. Interference studies showed no significant interference from the other common plant volatile compounds. Synthetic analyte studies revealed that the bi-enzyme based biosensor can be used to reliably detect methyl salicylate released by unhealthy plants.
authors.affiliation: Nano Electrochemistry Laboratory, College of Engineering, University of Georgia, Athens, GA 30602, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Department of Microbiology, University of Georgia, Athens, GA 30602, United States.
authors.forename: Hannah
authors.initials: H
authors.lastname: Bullock
authors.affiliation: College of Engineering, University of Georgia, Athens, GA 30602, United States.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Lee
authors.affiliation: Nano Electrochemistry Laboratory, College of Engineering, University of Georgia, Athens, GA 30602, United States.
authors.forename: Narendran
authors.initials: N
authors.lastname: Sekar
authors.affiliation: College of Engineering, University of Georgia, Athens, GA 30602, United States.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Eiteman
authors.affiliation: Department of Microbiology, University of Georgia, Athens, GA 30602, United States.
authors.forename: William B
authors.initials: WB
authors.lastname: Whitman
authors.affiliation: Nano Electrochemistry Laboratory, College of Engineering, University of Georgia, Athens, GA 30602, United States. Electronic address: rama@uga.edu.
authors.forename: Ramaraja P
authors.initials: RP
authors.lastname: Ramasamy
mesh_terms: D000363:Agaricales / Q000737:chemistry / Q000201:enzymology*; D015374:Biosensing Techniques / Q000379:methods*; D003001:Cloning, Molecular; D055664:Electrochemical Techniques / Q000379:methods; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D057230:Limit of Detection; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D014442:Monophenol Monooxygenase / Q000737:chemistry / Q000378:metabolism*; D037742:Nanotubes, Carbon / Q000737:chemistry; D010944:Plants / Q000737:chemistry / Q000378:metabolism*; D016958:Pseudomonas putida / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012459:Salicylates / Q000032:analysis* / Q000378:metabolism; D014159:Transducers
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D011994:Recombinant Proteins; D012459:Salicylates; D006899:Mixed Function Oxygenases; C022619:salicylate 1-monooxygenase; D014442:Monophenol Monooxygenase; C033069:methyl salicylate
keywords: Biosensor; Methyl salicylate; Salicylate hydroxylase; Tyrosinase; Volatile organic compound