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 a cid from deep trap photoluminescent states to "band edge"-type luminescence are probed. The presence of fivefold excess sulfide relative to cadmium co ncentration during cluster synthesis, followed by mild heating at 80 degree s C, results in the desired transformation of the Q-CdS emission spectrum. We also indirectly analyze the accompanying structural changes in the polym eric stabilizer, accomplished in this case by use of well-known spectrofluo rometric methods with the dyes ethidium bromide and trisphenanthroline ruth enium(II).