目的:采用表面等离子共振(surface plasmon resonance,SPR)生物传感器测定β-淀粉样多肽(Ap)人源性单链抗体E3 scfv的亲和力。方法:将Aβ_(1-40)固定于传感芯片表面,以E3 scfv等抗体为流动相,实时监测抗原抗体的结合和解离过程,并对其相互作用模式和动力学常数进行分析。结果:E3 scfv、阳性对照抗体DE284均能与Aβ_(1-40)发生特异性免疫结合反应,阴性对照抗体9E10则不能结合Aβ_(1-40);Aβ_(1-40)与E3 scfv及DF284的结合呈现快结合慢解离的动力学过程,其中DE284与Aβ_(1-40)的亲和力为6.77×10~(-7)mol/L,E3 scfv的亲和力为5.38×10~(-6)mol/L。结论:SPR适宜用作测定E3 scfv与Aβ_(1-40)的亲和力。 OBJECTIVE: To determine the affinity of β-amyloid polypeptide (Ap) humanized single chain antibody E3 scfv by surface plasmon resonance (SPR) biosensor. Methods: Aβ_ (1-40) was immobilized on the surface of the sensor chip. E3 scfv and other antibodies were used as the mobile phase to monitor the binding and dissociation of antigen and antibody in real time. The interaction modes and kinetic constants were also analyzed. Results: E3 scfv and DE284 could both specifically bind to Aβ 1-40, while negative control antibody 9E10 could not bind to Aβ 1-40; Aβ 1-40 and E3 scfv and DF284 The binding affinity of DE284 to Aβ 1-40 was 6.77 × 10 -7 mol / L, and the affinity of E3 scfv was 5.38 × 10 -6. mol / L. Conclusion: SPR is suitable for determining the affinity of E3 scfv to Aβ 1-40.