Anti-PLA2R antibody is only expressed in podocytes from patients with idiopathic membranous nephropathy (IMN). The detection of anti-PLA2R antibody in serum is therefore able to obtain essential information for rapid diagnosis and evaluation of the disease activity of IMN. In the present study, a polydopamine nanosphere-based fluorescent sensor was constructed for direct detection of anti-PLA2R antibodies in human serum. In this sensing system, the double-stranded DNA was phosphorylated under the action of anti-PLA2R antibody and the single-stranded DNA was cut by exonuclease. The single-stranded DNA was then adsorbed on polydopamine microspheres. The fluorescent groups labeled on the DNA were quenched, and the concentration of anti-PLA2R antibody was detected quantitatively by measuring the fluorescence signal changes before and after the reaction. The experimental results show that the method has a good linear detection range between 0.05 and 10 μg/mL for anti-PLA2R antibody and the detection limit is 0.02 μg/mL.

Graphical abstract

抗PLA2R抗体仅在特发性膜性肾病（IMN）患者的足细胞中表达。因此，血清中抗PLA2R抗体的检测能够获得必要的信息，以快速诊断和评估IMN的疾病活性。在本研究中，构建了一种基于聚多巴胺纳米球的荧光传感器，用于直接检测人血清中的抗PLA2R抗体。在该传感系统中，双链DNA在抗PLA2R抗体的作用下被磷酸化，单链DNA被核酸外切酶切割。然后将单链DNA吸附在聚多巴胺微球上。DNA上标记的荧光基团被淬灭，通过测量反应前后的荧光信号变化来定量检测抗PLA2R抗体的浓度。实验结果表明，该方法对抗PLA2R抗体具有良好的线性检测范围，介于0.05和10μg/ mL之间，检出限为0.02μg/ mL。

图形概要