Remote switching of cellular activity and cell signaling using light in conjunction with quantum dots

Stimulating cells by using light is a non-invasive technique that provides flexibility in probing different locations while minimizing unintended effects on the system. We propose a new way to make cells photosensitive without using genetic or chemical manipulation, which alters natural cells, in conjunction with Quantum Dots (QDs). Remote switching of cellular activity by optical QD excitation is demonstrated by integrating QDs with cells: CdTe QD films with prostate cancer (LnCap) cells, and CdSe QD films and probes with cortical neurons. Changes in membrane potential and ionic currents are recorded by using the patch-clamp method. Upon excitation, the ion channels in the cell membrane were activated, resulting in hyperpolarization or depolarization of the cell.