Rapid and sensitive detection of foodborne pathogens via nanoparticle-assisted ICP-MS and electrochemical multimodal analysis.

Foodborne pathogens-induced diseases are a major global public health concern. We have developed a novel sandwich hybridization technique that integrates magnetic separation with noble metal nanoparticle labeling, enabling the rapid, highly specific, and sensitive detection of Salmonella typhimurium, Vibrio parahaemolyticus, and Shigella sonnei, simultaneously. This technique involves forming sandwich-structure complexes by hybridizing pathogen DNA with corresponding report probe-grafted noble metal nanoparticles and capture probe-grafted magnetic nanoparticles (MNPs). These complexes are magnetically separated and analyzed using inductively coupled plasma mass spectrometry (ICP-MS), where the noble metal content correlates with the pathogen DNA concentration. Furthermore, changes in conductivity are monitored through electrochemical differential pulse voltammetry, enhancing detection reliability. The dual-sensing approach allows precise quantification of multiple pathogens simultaneously, with a wide detection range of 101 to 1010 copies·mL-1 and a low detection limit of 1 copy·mL-1. Successful application in real samples underscores its potential for ensuring food safety.