The dynamic process of nanoparticle aggregation, especially the salt-induced aggregation that has a high aggregation rate in 300 seconds, is an obstacle to accurate signal capture in a predetermined time and well-repeatable result acquisition for biosensing purposes. In this study, chromatography paper was used to inhibit the aggregating process of gold nanoparticles (AuNPs) in a label-free ssDNA and unmodified AuNP system. To verify the inhibition ability of the chromatography paper towards AuNP aggregation, the aggregation behavior of AuNPs in solution state and on the chromatography paper was studied through monitoring the surface plasmon resonance (SPR) absorbance of 13 nm AuNPs at 520 and 650 nm (A₆₅₀/A₅₂₀). To avoid the effect of environmental light during data acquisition, a UV-vis diffuse reflectance spectrometer was employed for paper samples instead of a smartphone as a signal recorder. Then, the paper-based biosensor was applied to our pH alarm system and the biosensing of ochratoxin A, and the results showed that the paper-based assay provided accurate sensing results with stable signals as compared to the solution assay.

中文翻译：

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纸基读数可提高基于金纳米粒子聚集的比色生物传感器的测量精度

纳米粒子聚集的动态过程，尤其是在300秒内具有高聚集速率的盐诱导的聚集，是在预定时间内准确捕获信号以及为生物传感目的获得可重复的结果的障碍。在这项研究中，色谱纸被用来抑制无标记的ssDNA和未修饰的AuNP系统中金纳米颗粒（AuNPs）的聚集过程。为了验证色谱纸对AuNP聚集的抑制能力，通过监测520和650 nm（A ₆₅₀）处的13 nm AuNPs的表面等离振子共振（SPR）吸光度，研究了AuNPs在溶液状态下和在色谱纸上的聚集行为/阿₅₂₀）。为避免数据采集过程中环境光的影响，纸样品采用了紫外可见漫反射光谱仪，而不是使用智能手机作为信号记录仪。然后，将纸基生物传感器应用于我们的pH报警系统和曲霉毒素A的生物传感，结果表明，与溶液法相比，纸质化验提供了稳定信号的准确传感结果。