Laboratório de Nanoestruturas Plasmônicas, Núcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos em Materiais, Departamento de Química, Universidade Federal de Juiz de Fora, Juiz De Fora, MG, Brazil.
Laboratório de Materiais Aplicados e Interfaces, Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Spectrochim Acta A Mol Biomol Spectrosc. 2023 Jan 5;284:121753. doi: 10.1016/j.saa.2022.121753. Epub 2022 Aug 12.
Gold nanoparticles (AuNPs) are attractive structures for biosensing, most due to different properties at nanoscale and biocompatibility. Localized surface plasmon resonance (LSPR) is one of these properties; LSPR enable the electromagnetic field enhancement closer to metallic surface, which allows surface-enhanced spectroscopies, like surface enhanced fluorescence (SEF). In this study, an immuno-biosensor based on gold nanorods (AuNRs) and SEF was constructed for simple and fast analysis to detect albumin antibody (anti-BSA) using antigen-antibody (anti-BSA/BSA) interaction as the biorecognition model. AuNRs were presented in two distinct configurations, in suspension (S-AuNRs) and adsorbed on glass slides (AuNRs-chip), and the detection was performed through an extrinsic method, wherein the SEF signal of a reporter molecule (IR-820 cyanine-type dye) was monitored. The analyte detection was evidenced by SEF mapping, where the average signal in the presence of anti-BSA was three times more intense than for the assay in the absence of analyte. A digital protocol was proposed to simplify the spectroscopic data analysis and reduce the intensity variability; in this protocol the number of positive events in the presence of anti-BSA is much larger (around two times) compared to the absence of analyte. The AuNRs based SEF immuno-biosensor allowed an efficient and simple analysis with specific biorecognition and may contribute as an efficient spectroscopy platform for immuno-biosensing.
金纳米粒子（AuNPs）是生物传感的理想结构，这主要是由于其在纳米尺度上的不同性质和生物相容性。局部表面等离子体共振（LSPR）就是这些性质之一；LSPR 使电磁场增强更接近金属表面，从而允许表面增强光谱学，如表面增强荧光（SEF）。在这项研究中，构建了基于金纳米棒（AuNRs）和 SEF 的免疫生物传感器，用于通过基于抗原-抗体（anti-BSA/BSA）相互作用的生物识别模型进行简单快速的分析，以检测白蛋白抗体（anti-BSA）。AuNRs 呈现出两种不同的状态，即悬浮状态（S-AuNRs）和吸附在玻璃载玻片上（AuNRs-chip），并通过外差法进行检测，其中监测报告分子（IR-820 花菁型染料）的 SEF 信号。通过 SEF 图谱证实了分析物的检测，其中存在 anti-BSA 时的平均信号比不存在分析物时的信号强三倍。提出了一种数字协议来简化光谱数据分析并降低强度变异性；在该协议中，存在 anti-BSA 时阳性事件的数量（大约两倍）比不存在分析物时多得多。基于 AuNRs 的 SEF 免疫生物传感器允许进行高效且简单的分析，具有特定的生物识别能力，并且可以作为免疫生物传感的有效光谱学平台。
