In this study, a novel ratiometric fluorescent nanoprobe for pH monitoring has been developed by synthesizing red fluorescent Ag₂S quantum dots (Ag₂S QDs) and green fluorescent carbon dots (CDs) nanohybrids (Ag₂S CDs) in one pot using CDs as templates. The nanoprobe exhibits dual-emission peaks at 500 and 670 nm under a single-excitation wavelength of 450 nm. The red fluorescence can be selectively quenched by increasing pH, while the green fluorescence is an internal reference. Therefore, the change of the relative fluorescence intensity (I₅₀₀/I₆₇₀) in the ratiometric Ag₂S CDs probes can be used for pH sensing. The results revealed that I₅₀₀/I₆₇₀ of Ag₂S CDs probes was linearly related to pH variation between pH 5.4 and 6.8. Meanwhile, the Ag₂S CDs probes possessed a good reversibility along with pH changing between 5.0 and 7.0 without any interruption from common metal ions, proteins and other interferences.

在这项研究中，通过使用CD在一个锅中合成红色荧光Ag ₂ S量子点（Ag ₂ S QDs）和绿色荧光碳点（CDs）纳米杂化物（Ag ₂ S CD），从而开发了一种用于pH监测的新型比例荧光纳米探针。作为模板。纳米探针在450 nm的单激发波长下在500和670 nm处显示双发射峰。可以通过增加pH值来选择性地淬灭红色荧光，而绿色荧光是内部参考。因此，比率式Ag ₂ S CDs探针中的相对荧光强度（I ₅₀₀ / I ₆₇₀）的变化可用于pH传感。结果显示我₅₀₀ / I₆₇₀个Ag ₂ S CDs探针与pH值5.4和6.8之间的线性相关。同时，Ag ₂ S CDs探针具有良好的可逆性，并且pH值在5.0至7.0之间变化，而不会受到常见金属离子，蛋白质和其他干扰物的干扰。