LAUSR

Thrombin is a marker of blood-related diseases and its detection is of great significance in the fields of medical and biological research. Herein, a novel chemiluminescence (CL) sensor for thrombin detection was prepared based on dual-aptamer biorecognition and mesoporous silica encapsulated with iron porphyrin. Mesoporous silica encapsulated with hematin by aptamer1 (Apt1/hematin/M-SiO2), and magnetic microspheres modified by aptamer2 (Apt2/NH2-MS) were successfully prepared, and the two materials were used to construct CL sensor to detect thrombin. Primarily, Apt2/NH2-MS is used for pretreatment separation of thrombin samples by the biorecognition effect between aptamer (Apt2) and target (thrombin). Then, thrombin/Apt2/NH2-MS is again recognized with Apt1 on the surface of Apt1/hematin/M-SiO2, and Apt1/thrombin/Apt2/NH2-MS is formed, so dual-aptamer biorecognition is realized. Meanwhile, generated Apt1/thrombin/Apt2/NH2-MS makes Apt1 shed off the surface of M-SiO2 and release hematin. Released hematin can catalyze luminol-H2O2 CL reaction. Therefore, the sandwich type of CL sensor was constructed based on dual-aptamer biorecognition and hematin catalysis for detection of thrombin. The sensor have a linear range of 7.5 × 10-15 to 2.5 × 10-10 mol.L-1 and a detection limit of 2.2 × 10-15 mol.L-1, and also exhibits excellent selectivity, reproducibility and stability. The sensor was successfully used for the detection of thrombin in serum samples, which makes it possible to apply the sensor to the detection of thrombin in actual samples.