A porous membrane-based microelectroanalytical technique for evaluating locally stimulated culture cells

We have investigated a technique for the local stimulation of cultured cells by considering the combination of electrochemical bioassay using scanning electrochemical microscopy (SECM). The device for the local stimulation was prepared by binding a permeable substrate made of a microporous alumina membrane (pore size 0.02 (mu)m, surface porosity 50%) and a micromask made of an elastomeric poly-(dimethylsiloxane) (PDMS) (40 (mu)m thickness having a 50 (mu)m diameter hole). HeLa cells were cultured on the membrane and a chemical (ethanol, in this study) was locally delivered from the opposite phase. The live–dead staining experiments showed that the ethanol stimulation was applied only to the cells in the area defined by the micromask. The electroactive species around the stimulated and non-stimulated cells were simultaneously measured by SECM using a 5.0 (mu)m-radius Pt microelectrode as a probe at -0.5 V versus Ag/AgCl and comparatively evaluated.