Efficient Capture and T2 Magnetic Resonance Assay of Candida albicans with Inorganic Nanoparticles: Role of Nanoparticle Surface Charge and Fungal Cell Wall

The early detection of fungi through a facile and straightforward method is desirable. The isolation of fungi from a body fluid sample plays a major role in effective detection. In the past, concanavalinA (conA), one of the lectins, interacted with Candida albicans through the surface component of the yeast cell wall. The development of a facile method with a robust binding affinity and an efficient capture of the yeast in addition to conA could pose a potential for the sandwich-like assay of C. albicans. In this study, the feasibility of an electrostatic interaction-mediated yeast capture was investigated as compared to conA-mediated binding. Also, the optimal parameters for the efficient isolation of C. albicans by surface-charged nanoparticles were studied, and the mechanism of the binding site through the electrostatic interaction on the surface of the yeast cell wall was explored by a blocking experiment. Furthermore, the yeast strains were found to interact uniformly only via the positively charged nanoparticles, and the captured yeast could be analyzed by FITC-conA fluorescence staining and T2 magnetic resonance assay. Thus, this strategy established a rapid and highly efficient method for the isolation of fungi and analysis.