Glutathione-Conjugated\nFluorometric Ratiometric NIR-Silicon\nNanoparticles and Its Applications for In Vitro and In Vivo Imaging

Glutathione (GSH), a tripeptide molecule, is the most\nabundant\nnonprotein biothiol in living cells, playing a crucial role in preventing\noxidative damage to cellular components and maintaining intracellular\nredox homeostasis. As a thiol molecule, GSH contains a sulfhydryl\n(–SH) group that is vital for the body’s response to\nreactive oxygen species (ROS). To confirm whether GSH can be used\nas a bioindicator or in the early diagnosis of cancers at the cellular\nlevel, it is essential to achieve highly selective detection and conjugation\nof GSH to silicon nanoparticles (SiNPs) under pathological conditions.\nWe are herein excited to report a type of fluorescent ratiometric\nnear-infrared silicon nanoparticle (NIR-SiNP) probe, that is, glutathione\npeptide conjugated (NIR-SiNPs-GSH), which simultaneously possess small\npore sizes at an average of 6.7 nm, an emission of 670 nm, a bioimaging\nfunctionality of living cancer cells and animals, and favorable biocompatibility.\nTaking advantage of these virtues, we further manifest that such resulting\nNIR-SiNPs, NIR-SiNPs-GSH bioprobes are marvelously worthy for immunofluorescence\nimaging of cancer cells and living mice. Furthermore, it was shown\nthat DAPI and probes could selectively stain malignant tumor cell\nnuclei, indicating the possibility for bioimaging and identification\nof cancer cells and animals. In summary, the suggested NIR-SiNPs-GSH\nprobe has the potential to be a very effective chemical tool for early\ntumor detection in the future.