Aqueous synthesis of bright near-infrared-emitting Zn-Cu-In-Se quantum dots for multiplexed detection of tumor markers

Aqueous synthesis is a green but challenging pathway to produce cadmium-free,bright,and near-infrared(NIR)emitting quantum dots(QDs).Herein,we develop a straightforward aqueous phase approach to prepare Zn-Cu-In-Se QDs with tunable emission from 630 to 800 nm through varying the molar ratio of Zn and Cu.The ultrasmall nanoparticle size remains nearly fixed(~2.6 nm)when the QD composition is varied,allowing for the effects of composition on the optical properties of QDs to be decoupled from the impact of particle size.By leveraging the off-stoichiometric effect on photoluminescence(PL),Zn-Cu-In-Se QDs with a Zn:Cu molar ratio of 1.0 show a long PL decay lifetime of 211 ns and an absolute photoluminescence quantum yield(PLQY)of 14.2%.The PLQY is further enhanced by overcoating a ZnS shell,reaching up to 25.8%.Based on the bright,biocompatible,and emission-tunable QDs,nanoprobes with targeting capability for multiple tumor markers are further constructed and employed to simultaneously ascertain targets in the cytoplasm and cell membrane.This study provides a green and effective strategy for achieving bright and biocompatible NIR quantum dots for multiplexed biodetection applications.

Generation and Developmental Characteristics of Porcine Tetraploid Embryos and Tetraploid/diploid Chimeric Embryos

The aim of this study was to optimize electrofusion conditions for generating porcine tet- raploid （4n） embryos and produce tetraploid/diploid （4n/2n） chimeric embryos. Different electric field intensities were tested and 2 direct current （DC） pulses of 0.9 kV/em for 30 p.s was selected as the optimum condition for electrofusion of 2-cell embryos to produce 4n embryos. The fusion rate of 2-cell embryos and the development rate to blastocyst of presumably 4n embryos, reached 85.4% and 28.5%, respectively. 68.18% of the fused embryos were found to be 4n as demonstrated by fluorescent in situ hybridization （FISH）. Although the number of blastomeres in 4n blastocysts was significantly lower than in 2n blastocysts （P 〈 0.05）, there was no significant difference in developmental rates of blastocysts between 2n and 4n embryos （P 〉 0.05）, suggesting that the blas- tocyst forming capacity in 4n embryos is similar to those in 2n embryos. Moreover, 4n/2n chimeric embryos were obtained by aggregation of 4n and 2n embryos. We found that the developmental rate and cell number of blastocysts of 4-cell （4n）/4-cell （2n） chimeric embryos were significantly higher than those of 2-cell （4n）/4-cell （2n）, 4-cell （4n）/8-cell （2n）, 4-cell （4n）/2-cell （2n） chimeric embryos （P 〈 0.05）. Consistent with mouse chimeras, the majority of 4n cells contribute to the trophectoderm （TE）, while the 2n cells are mainly present in the inner cell mass （ICM） of porcine 4n/2n chimeric embryos. Our study established a feasible and efficient approach to produce porcine 4n embryos and 4n/2n chimeric embryos.