2-D energy-resolved imaging of gold nanoparticle distribution at concentrations relevant for in-vitro studies

The present contribution lies in the framework of a research effort aimed at identifying the most suitable imaging techniques able to map the distribution of functionalized nanoparticles acting as biological markers taken up by specific cellular receptors in healthy and pathological biological tissues and to give a map of cellular radio-sensitivity across the tumor volume, in order to guide radiation dose prescription in intensity modulated radiotherapy (IMRT). To this aim we conceived and developed a custom compact spectroscopic module which accommodates a 10 mm² Silicon Drift Detector as well as a thermoelectric Peltier cooler and the front-end electronics. A slightly focusing polycapillary optics coupled to the detector allows performing 2D mapping in step and scan mode. We present the results obtained during a beam time in DIAMOND synchrotron source at beamline B16. Different Perspex phantoms have been measured: both single holes and two-holes in a donut configuration filled with different concentrations of gold nanoparticles (starting from 8 mg/ml down to 0.005 mg/ml).