Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan.
Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, Taiwan.
Int J Nanomedicine. 2020 Mar 26;15:2085-2094. doi: 10.2147/IJN.S237938. eCollection 2020.
Pregnancy-associated plasma protein-A and -A2 (PAPP-A and -A2) are principally expressed in placental trophoblasts and play a critical role in the regulation of fetal and placental growth. PAPP-A2 shares 45% amino acid similarity with PAPP-A. This study aimed to investigate the efficacy of real-time detection of PAPP-A and PAPP-A2 using a novel surface plasmon resonance (SPR) biosensor based on graphene oxide (GO).
Traditional SPR and GO-based SPR chips were fabricated to measure PAPP-A and PAPP-A2 concentrations. We compared SPR response curves of PAPP-A and PAPP-A2 between traditional SPR and GO-SPR biosensors. We also performed interference tests and specificity analyses among PAPP-A, PAPP-A2, and mixed interference proteins.
The time to detect PAPP-A and PAPP-A2 was about 150 seconds with both traditional SPR and GO-SPR biosensors. Approximately double SPR angle shifts were noted with the GO-SPR biosensor compared to the traditional SPR biosensor at a PAPP-A and PAPP-A2 concentration of 5 μg/mL. The limit of detection of the GO-SPR biosensor was as low as 0.5 ng/mL for both PAPP-A and PAPP-A2. Interference testing revealed that almost all of the protein bonded on the GO-SPR biosensor with anti-PAPP-A from the mixture of proteins was PAPP-A, and that almost no other proteins were captured except for PAPP-A2. However, the SPR signal of PAPP-A2 (5.75 mdeg) was much smaller than that of PAPP-A (13.76 mdeg). Similar results were noted with anti-PAPP-A2, where almost all of the protein bonded on the GO-SPR biosensor was PAPP-A2. The SPR signal of PAPP-A (5.17 mdeg) was much smaller than that of PAPP-A2 (13.94 mdeg).
The GO-SPR biosensor could distinguish PAPP-A and PAPP-A2 from various mixed interference proteins with high sensitivity and specificity. It could potentially be used to measure PAPP-A and PAPP-A2 in clinical blood samples during pregnancy.
妊娠相关血浆蛋白 A 和 -A2（PAPP-A 和 -A2）主要在胎盘滋养细胞中表达，在调节胎儿和胎盘生长中发挥关键作用。PAPP-A2 与 PAPP-A 具有 45%的氨基酸相似性。本研究旨在探讨基于新型氧化石墨烯（GO）的表面等离子体共振（SPR）生物传感器实时检测 PAPP-A 和 PAPP-A2 的效果。
传统 SPR 和基于 GO 的 SPR 芯片用于测量 PAPP-A 和 PAPP-A2 的浓度。我们比较了传统 SPR 和 GO-SPR 生物传感器的 PAPP-A 和 PAPP-A2 的 SPR 响应曲线。我们还对 PAPP-A、PAPP-A2 和混合干扰蛋白之间的干扰试验和特异性分析进行了研究。
传统 SPR 和 GO-SPR 生物传感器检测 PAPP-A 和 PAPP-A2 的时间约为 150 秒。在 PAPP-A 和 PAPP-A2 浓度为 5μg/mL 时，GO-SPR 生物传感器的 SPR 角度变化约为传统 SPR 生物传感器的两倍。GO-SPR 生物传感器对 PAPP-A 和 PAPP-A2 的检测限低至 0.5ng/mL。干扰试验表明，与混合物中的其他蛋白相比，与抗 PAPP-A 结合的几乎所有蛋白都是 PAPP-A，除了 PAPP-A2 外，没有其他蛋白被捕获。然而，PAPP-A2 的 SPR 信号（5.75mdeg）明显小于 PAPP-A（13.76mdeg）。用抗 PAPP-A2 进行的类似实验中，与 GO-SPR 生物传感器结合的几乎所有蛋白都是 PAPP-A2。PAPP-A 的 SPR 信号（5.17mdeg）明显小于 PAPP-A2（13.94mdeg）。
GO-SPR 生物传感器可以高灵敏度和特异性地区分 PAPP-A 和 PAPP-A2 与各种混合干扰蛋白。它有望用于测量妊娠期间临床血样中的 PAPP-A 和 PAPP-A2。
