Construction Of Molecularly Imprinted Electrochemical Biosensor And Its Analytical Detection Studytowardtryptophan And Tyrosine

Abnormal of small biological molecules（amino acid）lead to many diseases in human body,hence,the detection of the amount of amino acid is important.Detecting the concentration of amino acid via biosensor has become research hotpot.However,the high requirements of the recognition element on the work conditions have restricted the application of these sensors（such as enzymatic biosensor,antibody-antigen biosensor）.Owing to the specific recognition ability and excellent adaptive capacity to test environment,molecularly imprinted polymer（MIP）was introduced to biosensor as a kind of artificial biomimetic materials.Based on this,two kinds of molecularly imprinted biosensor were constructed for measurement of tryptophan and tyrosine in biological samples（human serum and urine）in this work.The following results were obtained through experimental research:（1）Biomass derived carbon was obtained via calcination using leaves of Lactuca sativa L.var.ramosa Hort as carbon resource,then the CuCo₂O₄@BC was prepared by hydrothermal method.MIP was synthesized using pyrrole as the monomer,tryptophan as the template on the GCE modified with CuCo₂O₄@BC.The corresponding characterization results indicated that the MIP/CuCo₂O₄@BC/GCE was successfully prepared.Followed by,the MIP/CuCo₂O₄@BC/GCE was employed to detect tryptophan in human serum and urine samples.The linear range was 0.01μmol/L-1μmol/L and 1μmol/L-40μmol/L,the limit of detection was3×10^-9mol/L.The standard addition method was utilized to detect the concentration of tryptophan in human serum and urine samples.The recovery ranges of human serum and urine samples were 97.67%to102.17%and 98.56%to 101.00%,respectively.（2）One sort of electrochemical dual-signal strategy was established to detect tyrosine in human serum.The Au nanoparticles@zeolitic imidazolate framework-67（Au@ZIF-67）was synthesized by wet chemical reduction method,and the GCE was modified with Au@ZIF-67.Then,the polythionine（pTH）was prepared on the Au@ZIF-67 modified GCE via electro-polymerization.Finally,the MIP was electropolymerized on the pTH/Au@ZIF-67/GCE.A series of characterization results confirmed the successful preparation of dual-signal electrochemical biosensor.Under optimal condition,the linear range of MIP/pTH/Au@ZIF-67/GCE was 0.01μmol/L-4μmol/L,and the limit of detection was 7.9×10^-10mol/L.The concentration of tyrosine in human serum was detectedviathe standard addition method,and the recovery was 95.8%to 118.0%.