The aim of this project is to develop a new method to immobilize aptamers of stem cells onto silicon-on-sapphire (SOS) substrates, to capture cells by affinity interaction between aptamer and target cells, and investigate two-dimensional electrochemical images of parameters such as local cell impedance, membrane surface-potential, ion channel activity, and two-photon fluorescence images with subcellular resolution using the impedance imaging technique Scanning Photo-induced Impedance Microscopy (SPIM) and the electrical potential imaging technique Light-Addressable Potentiometric Sensors (LAPS). Aptamers are artificial functional oligonucleic acids which can bind their respective targets with high affinity and specificity ranging from small inorganic or organic molecules to whole cells. The non-covalent affinity interaction between aptamer and cells support physiological integrin modulated cell attachment processes. Aptamers with specificity to target integrin heterodimers will be developed and patterned on LAPS substrates and the mechanism of attachment regulated stem cell differentiation studied. The proposed technique has the advantage that functional electrochemical imaging of the cell-surface interface can be carried out, which is not accessible to other electrochemical techniques.