A general strategy to target cells by nanoparticles for drug delivery, imaging, or diagnostics involves immunospecific binding between the probes and target molecules on the particles and on the cell surface, respectively, Usually, the macromolecular nature of the molecules requires a specific conformation to achieve the desired immunospecificity, and the extent of deposition of particles is limited by the number of receptor molecules present on the Cell. In this report, we successfully obtain targeted binding by decorating the nanoparticle with simple ions, such as Ca2+, without affecting the cell's vitality. The yeast cells for study, Saccharomyces cerevisiae, have no specific electrostatic affinity toward positive charge as confirmed by lysine-coated Au nanoparticles. The specificity of nanoparticle binding is found to be directly related to the metabolic vitality of the yeast cell (i.e., a significantly larger deposition occurs oil a younger generation with higher metabolism than oil older cells). The ion-mediated targeted deposition seems to be a general phenomenon for biologically important ions. as demonstrated by the contrast between Mg2+ and (toxic) Cd2+. The high density of (percolating) nanoparticle deposition as a monolayer oil the cells, as a result of the large number of ion receptors on the cell surface, is shown to be it potential method for building bioelectronic devices. The use of ions as all interface to target cells can have possible applications in diagnosing diseases and making biosensors using live cells.