Near−infrared (NIR) emitting Ag₂S quantum dots (QDs) are excellent fluorescent nanoprobes for bioassays with low toxicity. A novel fluorescent sensing platform which employing NIR fluorescent Ag₂S QDs and MnO₂ 2D nanosheets as NIR emitters and quenchers is designed for rapid and selective determination of glutathione (GSH). A facile and efficient approach was demonstrated for the synthesis of NIR fluorescent Ag₂S QDs with the emission of 845 nm. Then the NIR fluorescent nanoprobe of Ag₂S QDs−MnO₂ nanosheets is obtained by adsorbing Ag₂S QDs onto the surface of MnO₂ nanosheets which have atomically thick two−dimensional structure and high specific surface area. And the NIR fluorescence of Ag₂S QDs is quenched by the MnO₂ nanosheets. The presence of GSH could reduce MnO₂ to Mn²⁺ that results in the restoration of NIR fluorescence for Ag₂S QDs. The NIR fluorescent nanoprobe could be used for highly selective detection of GSH. Also a low detection limit of 60 μmol/L was obtained. Because NIR fluorescence of the Ag₂S QDs can efficiently reduce the interferences from background scattering and autofluorescence. The NIR fluorescent nanoprobe was directly applied to monitor the GSH level in human serum sample with high accuracy and precision.

发射Ag ₂ S量子点（QD）的近红外（NIR）是用于低毒性生物测定的出色荧光纳米探针。设计了一种新颖的荧光传感平台，该平台采用NIR荧光Ag ₂ S QD和MnO ₂ 2D纳米片作为NIR发射体和猝灭剂，用于快速，选择性地测定谷胱甘肽（GSH）。已证明了一种简便有效的方法可以合成发射845 nm的NIR荧光Ag ₂ S QD。然后Ag的NIR荧光纳米探针₂小号的QD-的MnO _2个纳米片是由吸附获得的Ag ₂小号的QD到的MnO的表面₂具有原子厚的二维结构和高比表面积的纳米片。Ag ₂ S QDs的NIR荧光被MnO ₂纳米片淬灭。谷胱甘肽的存在可以将MnO ₂还原为Mn ²⁺，从而恢复Ag ₂ S QD的NIR荧光。NIR荧光纳米探针可用于GSH的高选择性检测。还获得了60μmol/ L的低检测限。因为Ag ₂ S QD的NIR荧光可以有效地减少背景散射和自发荧光的干扰。NIR荧光纳米探针直接用于监测人类血清样品中GSH的含量，具有较高的准确性和准确性。