Portal de Periódicos da CAPES

Sensitive giant magnetoresistive-based immunoassay for multiplex mycotoxin detection

2009; Elsevier BV; Volume: 25; Issue: 7 Linguagem: Inglês

10.1016/j.bios.2009.11.028

1873-4235

Andy Mak, Sebastian J. Osterfeld, Heng Yu, Shan X. Wang, Ronald W. Davis, Olufisayo Jejelowo, Nader Pourmand,

Advanced biosensing and bioanalysis techniques

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.