Development of near-infrared region luminescent N-acetyl-L-cysteine-coated Ag

N-acetyl-L-cysteine (NAC) is a free radical scavenger. We developed NAC-coated Ag S (NAC-Ag S) quantum dot (QD) as an optical imaging and therapeutic agent. QDs were synthesized in water. Their optical imaging potential and toxicity were studied . NAC-Ag S QDs have strong emission, that is tunable between 748 and 840 nm, and are stable in biologically relevant media. QDs showed significant differences both in cell internalization and toxicity . QDs were quite toxic to breast and cervical cancer cells but not to lung derived cells despite the higher uptake. NAC-Ag S reduces reactive oxygen species (ROS) but causes cell death via DNA damage and apoptosis. NAC-Ag S QDs are stable and strong signal-generating theranostic agents offering selective therapeutic effects.