One of the most prevalent causes of foodborne illnesses worldwide is staphylococcal food poisoning. This study aimed to provide a robust method to extract the bacteriaStaphylococcus aureusfrom food samples using glycan-coated magnetic nanoparticles (MNPs). Then, a cost-effective multi-probe genomic biosensor was designed to detect the nuc gene ofS. aureusrapidly in different food matrices. This biosensor utilized gold nanoparticles and two DNA oligonucleotide probes combined to produce a plasmonic/colorimetric response to inform users if the sample was positive forS. aureus. In addition, the specificity and sensitivity of the biosensor were determined. For the specificity trials, theS. aureusbiosensor was compared with the extracted DNA ofEscherichia coli,Salmonella entericaserovar Enteritidis (SE), andBacillus cereus.The sensitivity tests showed that the biosensor could detect as low as 2.5 ng/µL of the target DNA with a linear range of up to 20 ng/µL of DNA. With further research, this simple and cost-effective biosensor can rapidly identify foodborne pathogens from large-volume samples.