A localized surface plasmon resonance (LSPR) effect was used to distinguish cell concentration on ordered arrays of Au nanoparticles (NPs) on glass substrates. Human-derived retinal pigment epithelial RPE-1 cells with flatter bodies and higher confluency were compared with breast cancer MCF-7 cells. Nanosphere lithography was used to form Au NPs with average diameters of 500 and 60nm in order to compare cell detection range, resonance peak shift, and cell concentration sensitivity. A larger cell concentration range was detected on the larger 500nm Au NPs compared to 60nm Au NPs (8.56×103-1.09×106 vs. 3.43×104-2.73×105cells/ml). Resonance peak shift could distinguish RPE-1 from MCF-7 cells on both Au NPs. RPE-1 cells consistently displayed larger resonance peak shifts compared to MCF-7 cells until the detection became saturated at higher concentration. For both types of cells, higher concentration sensitivity in the range of ~104-106cells/ml was observed on 500nm compared to 60nm Au NPs. Our results show that cells on Au NPs can be detected in a large range and at low concentration. Optimal cell sensing can be achieved by altering the dimensions of Au NPs according to different cell characteristics and concentrations.
All Science Journal Classification (ASJC) codes
- Biomedical Engineering