An integrated and sensitive detection platform for biosensing application based on Fe@Au magnetic nanoparticles as bead array carries

A sensitive and selective biosensor platform suited for SNP type using Fe@Au magnetic nanoparticles (GMNPs) to fabricate bead array is described. This new platform integrates the rapid binding kinetics of magnetic nanoparticles carriers, the multiplexing and encoding capabilities of chips, and tagged array. As a DNA sensor, the biotinylated single-stranded DNA was obtained by asymmetry PCR amplification, and then captured by GMNPs modified with streptavidin to form GMNP–ssDNA complexes without further purification. The complexes were immobilized on the slide to fabricate bead array through magnetic field. The bead array was hybridized with the corresponding allele-specific tag probes for each locus, and a pair of given universal detectors were applied to these markers analysis. Using bead array, all samples can be analyzed in one hybridization chamber which lowers the cost of the assay. Using universal tags, only a pair of universal dual-color probes labeled fluorophores was used for multiplex genotyping. Without the need of laborious and time-consuming elution, the experiment process was simple, reproducible and easy to handle. Two SNPs loci from 12 individual samples were discriminated using this platform and the results demonstrated that the expected scores and good discrimination were obtained between the two alleles from the two SNP loci. In summary, the integrated sensitive platform is adaptable and versatile, while offering a high-throughput capability needed for genome research and clinical applications.