High-sensitivity quantification of Tilletia foetida teliospores in wheat via immunomagnetic enrichment and gold nanoparticle-labeled ICP-MS immunoassay

A novel method for detecting Tilletia foetida teliospores in wheat was developed by integrating inductively coupled plasma mass spectrometry (ICP-MS) with an elemental labeling strategy. On the basis of an immunological method, capture magnetic beads coupled with a polyclonal antibody probe (MBs-pAb) were constructed to specifically enrich and label T. foetida teliospores. A gold nanoparticle-labeled monoclonal antibody was then added to bind to MBs-pAb. After dissociation of the resulting complexes using citric acid, the 197 Au signal was detected by ICP-MS, allowing for the quantitative detection of T. foetida spores. Under optimal conditions, the method had a limit of detection of 50 teliospores/mL and a linear range of 200–50,000 teliospores/mL. This new approach, which enables the rapid and highly sensitive detection of teliospores within 2.5 h, was successfully applied to wheat samples. The method shows significant potential for analyzing and monitoring common bunt of wheat, offering a robust tool for agricultural diagnostics and disease management.