标题：Label-free Electrochemiluminescent Immunosensor for Detection of Prostate Specific Antigen based on Aminated Graphene Quantum Dots and Carboxyl Graphene Quantum Dots
作者：Wu, Dan; Liu, Yixin; Wang, Yaoguang; Hu, Lihua; Ma, Hongmin; Wang, Guoqin; Wei, Qin
作者机构：[Wu, Dan; Liu, Yixin; Wang, Yaoguang; Hu, Lihua; Ma, Hongmin; Wang, Guoqin; Wei, Qin] Univ Jinan, Key Lab Chem Sensing & Anal, Shandong Univ, Sch Chem 更多
通讯作者地址：[Wei, Q]Univ Jinan, Key Lab Chem Sensing & Anal, Shandong Univ, Sch Chem & Chem Engn, Jinan 250022, Peoples R China.
摘要：Prostate-specific antigen (PSA) was used as the model, an ultrasensitive label-free electrochemiluminescent immunosensor was developed based on graphene quantum dots. Au/Ag-rGO was sythsized and used as electrode material to load a great deal of graphene quantum dots due to the large surface area and excellent electron conductivity. After aminated graphene quantum dots and acarboxyl graphene quantum dots were modified onto the electrode, the ECL intensity was much high using K2S2O8 as coreactant. Then, antibody of PSA was immobilized on the surface of modified electrode surface through the adsorption of Au/Ag toward proteins, leading to the decrease of the ECL intensity. As proven by ECL spectra test and electrochemical impedance spectroscopy (EIS) analysis, the fabrication process of the immunosensor is successful. Under the optimal conditions, the ECL intensity decreased linearly with the logarithm of PSA concentration in the range of 1 pg/mL similar to 10 ng/mL. The detection limit achieved is 0.29 pg/mL. The immunosensor results were validated through the detection of PSA in serum samples with satisfactory results. Due to excellent stability, high sensitivity, acceptable repeatability and selectivity, the immunosensor has promising applications in disease and drug analysis.