Thermochemical Passivation of DNA-Stabilized Q-Cadmium Sulfide Nanoparticles

In this work, the conditions required to transform quantum-confined cadmium sulfide (Q-CdS) nanoparticles stabilized by calf thymus deoxyribonucleic acid from deep trap photoluminescent states to “band edge”-type luminescence are probed. The presence of fivefold excess sulfide relative to cadmium concentration during cluster synthesis, followed by mild heating at 80°C, results in the desired transformation of the Q-CdS emission spectrum. We also indirectly analyze the accompanying structural changes in the polymeric stabilizer, accomplished in this case by use of well-known spectrofluorometric methods with the dyes ethidium bromide and trisphenanthroline ruthenium(II).