title: Sensitive detection of Ochratoxin A in food and drinks using metal-enhanced fluorescence.
abstract: Easy, sensitive, rapid and low cost ochratoxin biosensors are strongly demanded in food analysis since Ochratoxin A (OTA) is a widely diffused food contaminant, highly detrimental for human health. In this work, a novel plasmonic based optical biosensor prototype for ochratoxin A is described. It exploits the metal-enhanced fluorescence phenomenon due to the silver film over nanosphere plasmonic substrate. Since ochratoxin A could be present in different food commodities, sensor performances have been tested on three different matrices (dried milk, juices, and wheat mix). Firstly, a common OTA extraction solvent and a labeling and detection protocol were defined for the analyzed matrices. Then, the efficiency of the Ag-FON surfaces in signal amplification for the detection of low ochratoxin A concentrations was defined. Using samples spiked with OTA-AF 647 or with unlabeled OTA we were able to detect the mycotoxin at concentrations lower than E.U. specifications of 0.5 μg/kg in wheat, milk and apple juice. The test performances are comparable to those of ELISA kits but the platform presented here, once optimized, present some perspective advantages, such as: low cost and time consuming, versatility of the protocol for the investigation of different matrices, employment also in non-qualified laboratories, small dimensions that allow its integration in a compact device for OTA on-site detection.
authors.affiliation: Department of Chemical Sciences and INSTM, University of Padova, Via Marzolo 1, I-35131 Padova, Italy. Electronic address: francesco.todescato@unipd.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Todescato
authors.affiliation: Nanofabrication Facility (NanoFab), Veneto Nanotech S.C.p.A., Via S. Crispino 106, I -35129 Padova, Italy.
authors.forename: Agnese
authors.initials: A
authors.lastname: Antognoli
authors.affiliation: Nanofabrication Facility (NanoFab), Veneto Nanotech S.C.p.A., Via S. Crispino 106, I -35129 Padova, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Meneghello
authors.affiliation: Nanofabrication Facility (NanoFab), Veneto Nanotech S.C.p.A., Via S. Crispino 106, I -35129 Padova, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Cretaio
authors.affiliation: Department of Chemical Sciences and INSTM, University of Padova, Via Marzolo 1, I-35131 Padova, Italy.
authors.forename: Raffaella
authors.initials: R
authors.lastname: Signorini
authors.affiliation: Department of Chemical Sciences and INSTM, University of Padova, Via Marzolo 1, I-35131 Padova, Italy.
authors.forename: Renato
authors.initials: R
authors.lastname: Bozio
mesh_terms: D000818:Animals; D001628:Beverages / Q000032:analysis* / Q000382:microbiology; D015374:Biosensing Techniques / Q000379:methods; D005453:Fluorescence; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry* / Q000382:microbiology; D009183:Mycotoxins / Q000032:analysis*; D009793:Ochratoxins / Q000032:analysis*; D012834:Silver / Q000737:chemistry; D014908:Triticum / Q000737:chemistry* / Q000382:microbiology
chemical_list: D009183:Mycotoxins; D009793:Ochratoxins; C025589:ochratoxin A; D012834:Silver
keywords: Ag-FON; Metal-enhanced Fluorescence; Ochratoxin A; Plasmonic biosensor