Differentiation and determination of metal ions using fluorescent sensor array based on carbon nanodots

In chemical and biological sensing research, design and preparation of various sensors is a question of first importance. Generally, fabrication of specific sensors always requirs amounts of time-consuming and low-efficient synthetic tasks. Herein, a novel sensor array based on carbon nanodots (CDs) was constructed to differentiate and detect metal ions (including Ag+, Cd2+, Cr2+, Fe3+, Hg2+, and Pb2+), which utilized non-specific collective recognition reactions between CDs and various metal ions. The convenient synthetic methods and abundant carbon source greatly simplified the constructing process of the sensor array. Moreover, the hexa-sensor array can be simplified into binary-sensor array using principal component analysis (PCA) method. The binary-sensor array can be constructed in less than 10 min with competitive working performance as before. The binary-sensor array has its most comfort pH zone of around 5–10 and can perform well in the metal ion concentration of 50–1600 μM, suitable for the differentiation and determination of metal ions. The sensor array can also realize qualitative detection of unknown metal ions under the interference of a specific environment, including fetal calf serum and local running water.