Ermini Maria Laura, Chadtová Song Xue, Špringer Tomáš, Homola Jiří
Institute of Photonics and Electronics, Czech Academy of Sciences, Prague, Czechia.
Front Chem. 2019 Feb 4;7:40. doi: 10.3389/fchem.2019.00040. eCollection 2019.
Nanoparticles functionalized with specific biological recognition molecules play a major role for sensor response enhancement in surface plasmon resonance (SPR) based biosensors. The functionalization procedure of such nanoparticles is crucial, since it influences their interactions with the environment and determines their applicability to biomolecular detection in complex matrices. In this work we show how the ζ-potential (Zpot) of bio-functionalized gold spherical NPs (Bio-NPs) is related to the SPR sensor response enhancement of an immune-sandwich-assay for the detection of the carcinoembryonic antigen (CEA), a cancer marker for colorectal carcinomas. In particular, we prepare bio-functional nanoparticles by varying the amount of peptide (either streptavidin or antibody against CEA) bound on their surface. Specific and non-specific sensor responses, reproducibility, and colloidal stability of those bio-functional nanoparticles are measured via SPR and compared to ζ-potential values. Those parameters are first measured in buffer solution, then measured again when the surface of the biosensor is exposed to blood plasma, and finally when the nanoparticles are immersed in blood plasma and flowed overnight on the biosensor. We found that ζ-potential values can guide the design of bio-functional NPs with improved binding efficiency and reduced non-specific sensor response, suitable reproducibility and colloidal stability, even in complex matrixes like blood plasma.
用特定生物识别分子功能化的纳米颗粒在基于表面等离子体共振（SPR）的生物传感器的传感器响应增强中起着主要作用。此类纳米颗粒的功能化过程至关重要，因为它会影响它们与环境的相互作用，并决定它们在复杂基质中用于生物分子检测的适用性。在这项工作中，我们展示了生物功能化的金球形纳米颗粒（生物纳米颗粒）的ζ电位（Zpot）与用于检测癌胚抗原（CEA）（一种结直肠癌的癌症标志物）的免疫夹心测定的SPR传感器响应增强之间的关系。特别是，我们通过改变结合在其表面的肽（链霉亲和素或抗CEA抗体）的量来制备生物功能化纳米颗粒。通过SPR测量这些生物功能化纳米颗粒的特异性和非特异性传感器响应、重现性和胶体稳定性，并与ζ电位值进行比较。这些参数首先在缓冲溶液中测量，然后在生物传感器表面暴露于血浆时再次测量，最后在纳米颗粒浸入血浆并在生物传感器上流动过夜时测量。我们发现，ζ电位值可以指导生物功能化纳米颗粒的设计，使其具有更高的结合效率、更低的非特异性传感器响应、合适的重现性和胶体稳定性，即使在血浆等复杂基质中也是如此。
