ICCD camera technology with constant illumination source and possibilities for application in multiwavelength analytical ultracentrifugation

A new concept for multiwavelength detection in analytical ultracentrifugation is demonstrated, based on the technology of an Andor iStar intensified CCD camera and constant illumination source. The camera is coupled to an Andor Shamrock spectrograph providing a spectrometer system capable of UV/vis acquisitions with wavelengths from 190 to 790 nm. The details of the camera functions are described, and the essential operational modes demonstrated with proof of principle measurements. The Andor spectrometer system is proven to be much more sensitive than previous AUC detectors. In fact, it is so sensitive in high gain modes that signal quality is limited by photon shot-noise. Acquisition strategies are presented for detection systems working with low-light illumination sources, and the necessity of overcoming shot-noise limited signal quality is revealed. Several illumination optical concepts are tested and it is shown that when sufficient illumination is applied the detection system is capable of outperforming commercial and academic detectors previously reported in terms of signal-to-noise. A path forward for overcoming the remaining challenges is provided. The findings in this manuscript will be applicable to any type of high sensitivity detector design.