Synthesis of novel coordination polymer Cd-MOF and fluorescence recognition of tryptophan

The coordination polymer Cd-MOF with three-dimensional network structure was successfully synthe-sized by conventional solvothermal method, which possesses excellent chemical and structural stability. Among the 20 amino acids, only tryptophan (Trp) showed a significant fluorescence enhancement effect on Cd-MOF, which was attributed to the large overlap between the UV absorption peak of tryptophan and the fluorescence excitation spectrum of Cd-MOF, indicating that the UV absorption of them is com-petitive, which enhanced the UV absorption of Cd-MOF and thus enhanced the luminescence intensity simultaneously. The Cd-MOF was further found to have a low detection limit of 1.7 mu M, a relatively wide linear range (0-100 mu M) and a stable response time for the recognition of tryptophan, as well as a good re-sistance to the interference of other amino acids. The method has been successfully applied to the spiked recovery determination of tryptophan in milk with the recoveries of 99.6%-101% and RSD <= 1.50%. There-fore, this work demonstrated that Cd-MOF can be used as a fluorescent probe for the selective detection of tryptophan, and also may provide new opportunities for the rational design of future tryptophan fluo-rescent probes. (c) 2023 Elsevier B.V. All rights reserved.