Polyvinyl-pyrrolidone capped spherical cadmium sulphide quantum dots (CdS-PVP QDs), 2–6 nm in size, were developed as a selective turn-on fluorescence nanosensor for monohydrogen phosphate ion (HPO₄²⁻) in aqueous medium. Fluorescence intensity of CdS-PVP QDs significantly increased with addition of HPO₄²⁻ ions, whereas the other common inorganic ions had very little effect on the fluorescence intensity. The proposed sensor may be efficiently used for the detection of HPO₄²⁻ ions at a low level of concentration up to 213 nM in real urine sample. Cell imaging study indicates that the CdS-PVP QDs are cell permeable and can detect the intracellular distribution of HPO₄²⁻ ions under fluorescence microscope. The CdS-PVP QDs showed considerable activity against Staphylococcus aureus also.

聚乙烯吡咯烷酮封端的球形硫化镉量子点（CdS-PVP QDs），尺寸为2-6 nm，是一种选择性开启荧光纳米传感器，用于水性介质中的磷酸一氢离子（HPO ₄ ^2-）。添加HPO ₄ ^2-离子后，CdS-PVP QD的荧光强度显着增加，而其他常见的无机离子对荧光强度的影响很小。所提出的传感器可以有效地用于检测尿液中浓度高达213 nM的低浓度HPO ₄ ^2-离子。细胞成像研究表明CdS-PVP QD具有细胞渗透性，可以检测HPO ₄ ^2-的细胞内分布离子在荧光显微镜下。CdS-PVP QDs也显示出抗金黄色葡萄球菌的活性。