Flexibly regulated electrochemiluminescence of all-inorganic perovskite CsPbBr3 quantum dots through electron bridge to across interfaces between polar and non-polar solvents

All-inorganic perovskite quantum dots (QDs) have attracted great interests due to its outstanding properties. But their poor stability in polar solvents seriously hampered wide applications in analytical chemistry. In this work, strong, stable and flexibly regulated the electrochemiluminescence (ECL) emission form CsPbBr₃ QDs was successfully obtained and applied in the analysis of polar solvents through the unique structure of closed bipolar electrode (BPE). To demonstrate the feasibility, it was successfully used in the detection of tetracycline (Tc) aqueous solution. CsPbBr₃ QDs was immersed into organic solution in anode microcell of closed BPE while Tc aqueous solution was added into cathode microcell. The two microcells were physically separated and would not interfere with each other. But the bio-recognition event between aptamer and Tc in cathode microcell would induce the ECL signal change in anode microcell through the electrons conducted by BPE as the bridge. The ECL emission can be flexibly regulated by environmental factors of both polar and non-polar solvents and the interface status of the BPE. Compared with traditional methods to overcome the intrinsic instability in polar medium, the reported method does not need any further surface modifications, has no limitations on the targets and can provide wide development space for further deep research, which may open a new direction for the ECL sensing of CsPbBr₃ QDs.