Highly sensitive and selective fluorescence detection of thalidomide based on the endo-functionalized amide hybridtube

Thalidomide ( THD ) is a pharmacological agent characterized by notable immunomodulatory and anti-angiogenic activities. However, due to its severe teratogenicity and toxicity, regular monitoring of blood concentrations in patients is essential for preventing and controlling adverse reactions, as well as for tailoring individualized dosing regimens. Herein, by utilizing the indicator displacement assay (IDA) approach, a supramolecular sensor for highly sensitive and selective detection of THD was successfully developed based on an amide hybridtube ( HT ) and phenoxazine dyes. Attributed to the high affinity and selective binding of HT for THD in water (up to 2.49 × 10 6  M −1 ), the sensor exhibited excellent detection performance in both phosphate buffer and serum matrices, with linear ranges of 0.15–5.8 μM and detection limits of 0.017 μM and 0.059 μM, respectively. What's more, the method successfully achieved accurate detection of THD in pharmaceutical formulations and clinical serum samples, demonstrating its high sensitivity and remarkable anti-interference capability. To our knowledge, this is the first “turn-on” fluorescent probe capable of effectively quantifying THD in complex matrices. This breakthrough is poised to offer critical technical support for both research and clinical applications