The influence of biomolecules on the luminescence of defects in CdSe/ZnS quantum dots

The influence of bio-conjugation on photoluminescence (PL) spectra of CdSe/ZnS quantum dots (QDs), including the luminescence related to defects in quantum dots or at their surface is investigated. It is found that the bioconjugation results not only in a high-energy shift of the luminescence band caused by the exciton recombination in quantum dots but also in an increase of the contribution of the defect emission to luminescence spectra. It is shown that the contribution of different defects increases in different ways. The changes in defect emission spectra are explained by an increase of the number of corresponding luminescence centers