A label-free photonic crystal biosensor imaging method for detection of cancer cell cytotoxicity and proliferation

A label-free method for detecting the attachment of human cancer cells to a biosensor surface for rapid screening for biological activity is described, in which attachment of a cell results in highly localized increase of the resonant reflected wavelength of a photonic crystal narrowband reflectance filter incorporated into a standard 96-well microplate. An imaging detection instrument is used to determine the spatial distribution of attached cells by mapping the shift in reflected resonant wavelength as a function of position. The method enables monitoring of cancer cell attachment, cell proliferation, and cell detachment that is induced by exposure of the cells to drug compounds. We demonstrate the efficacy of this method as an early screening technique for the rapid quantification of the rate of cancer cell proliferation on the sensor surface, and subsequently as a means for quantifying cell detachment resulting from apoptosis that is induced by exposure of the cells to cytotoxic chemicals.