Abstract: An analytical method of and system for monitoring cell status whereby excitation energy is focused to an excitation cytometry volume in a cell sample to fluoresce first and second fluorophores of a cell. Fluorescence signals from the first and second fluorescing cell fluorophores are directed to a detection subsystem. A first peak in fluorescence intensity for the first fluorophore is detected as is a second peak in fluorescence intensity for the second fluorophore. The fluorescence signals are processed to identify when the first and second peaks occur substantially simultaneously indicating the presence of a cell at the excitation cytometry volume instead of background fluorescence and in response, the cellular status of the cell is measured using the intensity of the levels of the first and second peaks.

Abstract: Ultra near-field index modulated plasmonic nano-aperture label-free imaging methods and techniques are useful for imaging and detection of biological microparticles and nanoparticles such as circulating tumor exosomes (CTEs), bacteria and vimses. The methods and techniques utilize a high-density array of gold, silver, or gold/silver alloy nanodisks, in some cases on an undercut or invisible substrate. Given the relatively large nanodisk dimensions, the nanodisk array may feature a significantly blue-shifted LSPR extinction peak due to both far-field plasmonic coupling and substrate undercut. The ultra near-field imaging methods have the ability to image nanoparticles as small as 25 nm.