title: Sensitive giant magnetoresistive-based immunoassay for multiplex mycotoxin detection.
abstract: Rapid and multiplexed measurement is vital in the detection of food-borne pathogens. While highly specific and sensitive, traditional immunochemical assays such as enzyme-linked immunosorbent assays (ELISAs) often require expensive read-out equipment (e.g. fluorescent labels) and lack the capability of multiplex detection. By combining the superior specificity of immunoassays with the sensitivity and simplicity of magnetic detection, we have developed a novel multiplex magnetic nanotag-based detection platform for mycotoxins that functions on a sub-picomolar concentration level. Unlike fluorescent labels, magnetic nanotags (MNTs) can be detected with inexpensive giant magnetoresistive (GMR) sensors such as spin-valve sensors. In the system presented here, each spin-valve sensor has an active area of 90 microm x 90 microm, arranged in an 8 x 8 array. Sample is added to the antibody-immobilized sensor array prior to the addition of the biotinylated detection antibody. The sensor response is recorded in real time upon the addition of streptavidin-linked MNTs on the chip. Here we demonstrate the simultaneous detection of multiple mycotoxins (aflatoxins B(1), zearalenone and HT-2) and show that a detection limit of 50 pg/mL can be achieved.
authors.affiliation: Stanford Genome Technology Center, Stanford University, 855 California Ave, Palo Alto, CA 94304, USA.
authors.forename: Andy C
authors.initials: AC
authors.lastname: Mak
authors.forename: Sebastian J
authors.initials: SJ
authors.lastname: Osterfeld
authors.forename: Heng
authors.initials: H
authors.lastname: Yu
authors.forename: Shan X
authors.initials: SX
authors.lastname: Wang
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Davis
authors.forename: Olufisayo A
authors.initials: OA
authors.lastname: Jejelowo
authors.forename: Nader
authors.initials: N
authors.lastname: Pourmand
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D003217:Conductometry / Q000295:instrumentation* / Q000379:methods; D017097:Electric Impedance; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation*; D005506:Food Contamination / Q000032:analysis*; D007118:Immunoassay / Q000295:instrumentation*; D008280:Magnetics / Q000295:instrumentation*; D009183:Mycotoxins / Q000032:analysis*
chemical_list: D009183:Mycotoxins