multi-emission fluorescent sensor array based on carbon dots for distinguish of seven metal ions

Abstract: the development of a convenient method for detection and identification of toxic metal ions is of great interest [1]. the use of carbon dots (cds), as a new class of photoluminescent nanomaterials is rapidly expanding. their many advantages, including water solubility, high stability, low toxicity, ease of functionalization, and cost-efficient and simple synthetic routes have introduced them as potential alternatives to conventional semiconductor-based quantum dots [2, 3]. up to now, various fluorescence sensor arrays have been fabricated based on fluorescent carbon dots [4-6]. in this work, we have developed a facile fluorescent sensor array based on luminescence carbon dots for detecting and differentiating a set of metal ions. herein, we have designed three hydrothermal methods to synthesis three cds with red, green, and blue emission for distinguishing seven metal ions (au3+, ag+, pb2+, cd2+, fe3+, cu2+, and hg2+), at ph 6. the cds displayed various fluorescence quenching behaviors to ions, due to the presence of different functional groups on their surface. seven metal ions were distinguished in the concentration range of 0.20 to 70 μm. in this method, we were able to design three cds with different fluorescence emissions, and quenching responses to metal ions. also, the pca proved that the seven metals ions with different concentration could be discriminated from each other. the outcomes indicated that the number of sensor elements can be easily increased by changing the synthetic conditions of cds. the use of rgb cds with tunable optical properties will broaden an innovative way of developing efficient sensor array systems.