Label-free cell-based assay using localized surface plasmon resonance biosensor

For an understanding of the life activities, the analysis of cells, which are the smallest units of life form, has a significant impact on biology and biotechnology. In this study, we propose a novel label-free cell-based assay that is based on localized surface plasmon resonance (LSPR) biosensor, which is excited using core–shell structured nanoparticle layer substrate. To demonstrate the promising properties of our LSPR-based label-free cell-based assay, we performed the detection of the cell metabolites using the isolated cells from mouse thymus. For detection of the cellular metabolites, the refractive index change by the specific interaction between the antigen and antibody was detected on the antibody immobilized LSPR-based biosensor. Using our LSPR-based biosensor, the optical characteristics were monitored for the detection of specific reactions between antibody and cell metabolites. As a result, the detection limit of this antibody immobilized LSPR-based biosensor was 10 pg mL−1. Furthermore, the time-course analysis of cell metabolisms using the isolated cells from mouse thymus was also achieved. From these results, the LSPR-based biosensor provides a promising platform with attractive advantages for the detection of biomolecular interactions at low-cost in a simplified experimental set-up with a low sample volume.