Construction of Nucleic Acid Aptamer Sensor and Detection of Histamine in Food
Objective:To construct a nucleic acid aptamer sensor for detection rapid of histamine in food.Methods:DNA-gold nanoparticles(AuNPs)nanocomposites were prepared by covalent binding of thiol groups and gold nanoparticles modified at the 5'end of G-quadruplex and adapter.Electrostatically adsorb histamine onto the surface of the electrode,incubate the nanocomposite,and the adapter in the composite binds specifically to histamine.The G-quadruplex sequence on nanocomposites combined with hemin in the substrate to form a G-quadruplex structure,which could catalyze the conversion of hydroquinone in the substrate to benzoquinone,under a certain voltage,benzoquinone was then reduced to produce detectable electrochemical signals,achieving quantitative detection of histamine.Results:Research on the performance of the newly constructed histamine sensor has found that at a histamine concentration of 1×10-6-1×10-4 μg/mL,the linear correlation coefficient of 0.9922 and the detection limit of 0.5 µg/mL.Specific analysis of the sensor revealed that the response signals of interferents(such as tyramine,L-cysteine,and histidine)were much lower than those of histamine;Stability analysis showed that after 30 days of storage,the sensor still maintained a response signal of no less than 95.1％of the initial response signal.In actual sample detection,the sample recovery rate ranged from 91.26％to 107.60％,and compared with high performance liquid chromatography detection,showing no difference in the results.Conclusion:The newly constructed nucleic acid aptamer sensor is an enzyme electrochemical sensor that can selectively capture and recognize histamine,has good specificity and stability,and can effectively reduce experimental costs and operational difficulties.
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