Aqueous synthesis of PbS quantum dots for noninvasive near-infrared fluorescence imaging in a mouse model

摘要

In this paper, we present a new facile and environmental friendly method to prepare water-soluble near-infrared (NIR)-emitting PbS quantum dots (QDs) at room temperature under ambient conditions, using dihydrolipoic acid (DHLA) as a stabilizer. The photoluminescence (PL) emissions of the prepared DHLA-capped PbS QDs are tunable between 870 and 1010 ran. A PL quantum yield (QY) of -10% can be achieved under optimized conditions without any post-preparative treatment. Here, we further use the produced DHLA-capped PbS QDs for NIR fluorescence imaging in a mouse model. The obtained experimental results showed that the NIR fluorescence of the PbS QDs in living tissues generated from the excitation with semiconductor laser (λ_(max)=765.9 nm) could penetrate living tissues and be detected easily by the noninvasive in vivo NIR fluorescence imaging system. In addition, the preliminary studies on the cytotoxicity and in vivo toxicity of the QDs also indicates fully that these water-soluble DHLA-capped PbS QDs are very lowly toxic, and as such they should have greater potential in biological and medical applications especially in noninvasive in vivo fluorescence imaging of mice, compared to other existing highly toxic aqueous NIR-emitting quantum dots (CdTe, HgTe, etc).