Icap q spectrometer

Characterization of the different synthesized photosensitizers was achieved by ¹H NMR spectroscopy recorded on a 600 MHz Bruker AVANCE NEO spectrometer and HR-MS (ESI positive, direct injection) recorded with a Bruker Impact II spectrometer. All UV-Vis spectra were recorded using a UV-1600PC spectrometer from VWR with a resolution of 1 nm. Surface analysis of the npAu supports and the final hybrid materials was performed on a scanning electron microscope (SEM, Supra 40, Zeiss) operated at 15.0 kV acceleration voltage, 300 pA probe current and 10 mm working distance and equipped with a Bruker XFalsh 6/30 EDX detector. For the quantification of immobilized photosensitizer, the hybrid material (10 mg) was dissolved in ultrapure aqua regia (2 mL) prior to determination by ICP-MS using an iCAP-Q spectrometer form Thermo Fisher Scientific.

Release of copper ions from the scaffolds soaked in simulated body fluid (SBF) was assessed by means of inductively-coupled plasma-mass spectrometer (ICP-MS; iCAP™ Q spectrometer, ThermoFisher Scientific, Waltham, MA, USA). SBF was prepared according to the protocol recommended by Kokubo and Takadama [23 (link)]. The scaffolds (triplicate samples) were maintained in polyethylene bottles filled with SBF at 37 °C in an incubator under static conditions; the copper release was monitored up to 30 days. A mass-to-volume ratio of 1.5 mg/mL was used, as recommended in previous studies [24 (link)]. At each time point, 1 mL aliquot of solution was collected and replaced with fresh SBF, as suggested in [24 (link)]. At the end of the experiment, the samples were extracted, rinsed with ultra-pure water, left to dry overnight at room temperatures and analyzed by SEM-EDS. The solution aliquots collected at each time point were analyzed by ICP-MS to determine copper elemental concentration.