Clean photoinduced generation of free reactive oxygen species by silica films embedded with CdTe-MTA quantum dots

摘要

CdTe quantum dots capped with mercaptopropionic acid, 3.5 nm in size, were entrapped in sol-gel films prepared with tetramethyl orthosilicate under mineral acidic catalysis in the presence of Triton X-100 as a non-ionic surfactant. The follow-up of the sol-gel process was performed in real-time both with fluorescent crystal violet as a molecular rotor and with quantum dots. Clusters of nanoparticles 500 nm in size become homogeneously distributed in the films, but preserving initial photoluminescence quantum yields (21%), and the emission spectrum had increased excited state lifetimes (65 +/- 4 ns) and photostability. Films photoactivation inside a multi-pumping flow system enabled reproducible generation of reactive oxygen species as determined by chemiluminescence using the alkaline luminol reagent, thus opening future developments for clean and environmentally friendly analytical applications.