Functionalized Nano Fiber Probe Mediated Portable Dual-Laser Induced Biosensor for Simultaneous Detection of Ochratoxin a and Aflatoxin B1

Abstract

A novel functionalized nano fiber probe mediated portable dual-laser induced biosensor (FNODB) was fabricated and employed for parallel detection of two targets in one sample. The OTA and AFB1 hapten-protein conjugates functionalized nano fiber probe embedded in optofluidic nano-chip was used for biorecognition, capturing, separation and signal transmitting while fluorescent dyes labelled antibodies was employed for signaling. The unique nanopore structure on the fiber probe was beneficial to increase immobilization number of biomolecules and enhance the interaction between evanescent wave field and fluorescent dyes, resulting in high detection sensitivity. Immunodynamic assay results demonstrated the bio-affinity reaction over functionalized nano fiber probe and corresponding antibodies belonged to first-degree kinetics and the cross-reactivity between the two groups of antigens/antibodies was negligible. Combining with evanescent wave dual-color fluorescence technology and immunoassay principle, the FNODB could realize simultaneous detection of OTA and AFB1 in one sample within 14 min based on time-resolved effect. LODs of 0.014 ng/mL for OTA and 0.12 ng/mL for AFB1 were obtained. The detection results for three real samples spiked with OTA and AFB1 by HPLC and FNODB demonstrated stronger line relationship, which proved the excellent accuracy and reliability of our fabricated method. With inherent advantages including miniaturization volume, field-deployment and reusable detection, the FNODB provided an economical, rapid and sensitive assay strategy for multi biotoxins parallel detection and could be easily extended in other pollutants simultaneous quantification.

Keywords: functionalized nano fiber probe, simultaneous detection, dual-laser, immunodynamic assay