Facile approach to observe and quantify the α_iIbβ₃ Integrin on a Single-Cell

We report for the first time seeing and counting integrin α_IIbβ₃ on a single-cell level. The proposed method is based on the using of the Au cluster probe. With the fluorescent property of Au₂₄ cluster and the specific targeting ability of peptide, our probe can directly visualize integrin α_IIbβ₃ on the membrane of human erythroleukemia cells (HEL) via confocal microscopy. On the basis of the accurate formula of our probe (Au₂₄Peptide₈), the number of integrin α_IIbβ₃ can be precisely counted by quantifying the gold content on a single HEL cell via laser ablation inductively coupled plasma mass spectrometry. Our results reveal that the number of integrin α_IIbβ₃ on a single cell varies from 5.75 × 10^-17 to 9.11 × 10^-17 mol, because of the heteroexpression levels of α_IIbβ₃ on individual cells.