Development of a QCM immunosensor with functionalized gold nanoparticles for the detection of Salmonella typhimurium

[Display omitted] •Surface modification of QCM is useful for Salmonella Typhimurium detection.•QCM-based immunosensor was developed for the detection of Salmonella typhimurium.•Immunosensor was carried out by functionalizing of QCM with immobilized AuNP.•Different sizes of AuNP influence the detection of Salmonella typhimurium.•High sensitivity and specificity were obtained in S.typhimurium detection. This study developed an immunosensor using the quartz crystal microbalance (QCM) to detect Salmonella typhimurium (S.typhimurium), using gold nanoparticles (AuNPs) as signal enhancers. The gold nanoparticles (AuNP) were functionalized with cysteinate and immobilized with a specific antibody to S.typhimurium (AbST). The previously treated gold nanoparticles were attached to the surface of the QCM for the detection of S.typhimurium. The effect of the gold nanoparticles size was explored to elucidate the optimal size as a signal enhancer.