Aix-Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France.
Analyst. 2017 Sep 8;142(18):3484-3491. doi: 10.1039/c7an01066d.
Conventional sandwich-type immunoassays are widely used for protein biomarker detection, yet their workflows are challenged by the need for multiple incubation steps separated by washing cycles. Conducting these immunoassays is thus rather time-consuming and labor-intensive. Moreover, the limited sensitivity around 0.1 ng mL is challenging the monitoring of cancer recurrence, for instance after radical prostatectomy in the case of prostate cancer. Here, we report a single-step homogeneous immunoassay using dual-color light scattering of metal nanoparticles. We detect human free prostate-specific antigen (f-PSA) in a buffered protein matrix solution with a single mixing and incubation step, no washing or purification cycle, and with a total experiment time of less than one hour. The limit of detection is 20 pg mL, which is 5× lower as compared to a conventional ELISA kit for f-PSA. The simpler, faster and more sensitive detection of cancer biomarkers opens promising opportunities to improve cancer diagnosis and health monitoring after cancer treatment.
传统的三明治型免疫分析被广泛用于蛋白质生物标志物的检测，但由于需要多次孵育步骤并通过洗涤循环分离，其工作流程受到挑战。因此，进行这些免疫分析既费时又费力。此外，约 0.1ng/mL 的有限灵敏度也给癌症复发的监测带来了挑战，例如在前列腺癌患者接受根治性前列腺切除术之后。在这里，我们报告了一种使用金属纳米粒子的双色光散射的单步均相免疫分析。我们在缓冲蛋白基质溶液中使用单步混合和孵育步骤检测人游离前列腺特异性抗原 (f-PSA)，无需洗涤或纯化循环，总实验时间不到一个小时。检测限为 20pg/mL，比用于 f-PSA 的传统 ELISA 试剂盒低 5 倍。癌症生物标志物的这种更简单、更快和更灵敏的检测为改善癌症诊断和癌症治疗后的健康监测提供了有前景的机会。
