Abstract As a convenience and robust point−of−care diagnostics technique for biomarkers, surface−enhanced Raman scattering (SERS)−based lateral flow immunoassay (LFIA) has attracted attentive attentions. In traditional paper−based LFIA, its hydrophilic surface with the so−called coffee−ring effect will inhibit the sensitivity and quantitative ability, which made the results less satisfying. Here, an attractive hydrophilic−hydrophobic polymer strip with Raman internal standard (IS) was developed by magnetron sputtering hydrophilic Ag nanoparticles (NPs) onto the specific area of the hydrophobic polydimethylsiloxane (PDMS). The target analytes can be enriched on the test and control lines formed by the hydrophilic Ag regions, which significantly improved the adaptability of SERS−based LFIA strip in the ultra−sensitive and quantitative monitoring of trace Ferritin (FER). Typically, assisted by raspberry−like Au NPs as immunoprobes, such hydrophilic−hydrophobic LFIA strip could achieve a limit of detection for FER as low as 0.41 pg/mL. Moreover, calibrated linear relationship with R2 values of 0.992 in the analysis was successfully demonstrated by rationally using the Raman signals of PDMS as a reference. Such an improved LFIA platform may give another promising technique for the trustworthy monitoring and treatment of cancer.

中文翻译：

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基于亲水-疏水 SERS 底物的改进侧流条用于超灵敏和定量免疫测定

摘要 作为一种方便且强大的生物标志物即时诊断技术，基于表面增强拉曼散射 (SERS) 的横向流动免疫分析 (LFIA) 已引起广泛关注。在传统的纸基LFIA中，其亲水表面具有所谓的咖啡环效应，会抑制灵敏度和定量能力，使结果不太令人满意。在这里，通过磁控管将亲水性银纳米粒子 (NPs) 溅射到疏水性聚二甲基硅氧烷 (PDMS) 的特定区域，开发了一种具有拉曼内标 (IS) 的有吸引力的亲水-疏水性聚合物条。目标分析物可以富集在由亲水性 Ag 区域形成的测试和控制线上，这显着提高了基于 SERS 的 LFIA 条在痕量铁蛋白 (FER) 的超灵敏和定量监测中的适应性。通常，在类似覆盆子的 Au NP 作为免疫探针的辅助下，这种亲水-疏水的 LFIA 条可以实现低至 0.41 pg/mL 的 FER 检测限。此外，通过合理使用PDMS的拉曼信号作为参考，成功证明了与分析中R2值为0.992的校准线性关系。这种改进的 LFIA 平台可能为可靠的癌症监测和治疗提供另一种有前途的技术。合理利用PDMS的拉曼信号作为参考，成功证明了分析中的992。这种改进的 LFIA 平台可能为可靠的癌症监测和治疗提供另一种有前途的技术。合理利用PDMS的拉曼信号作为参考，成功证明了分析中的992。这种改进的 LFIA 平台可能为可靠的癌症监测和治疗提供另一种有前途的技术。