Tiwari Atul Kumar, Narayan Roger J
Department of Chemistry, Indian Institute of Technology (BHU), Varanasi 221005, India.
Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27695, USA.
Biosensors (Basel). 2025 Sep 9;15(9):593. doi: 10.3390/bios15090593.
In FRET-based sensing, the interaction between the analytes and metal nanoparticles is significantly regulated by the physicochemical characteristics of the nanoparticles, such as their shape, size, zeta potential, surface-linked ligands, doping, pH of the medium, particle surface roughness, and lattice structure (atomic arrangements). During the synthesis process, to avert the aggregation of gold nanoparticles (AuNPs), synthetic polymers (including polyethylene glycol, polyethyleneimine, and poly-N-vinylpyrrolidone) and natural polymers (such as chitosan, starch, gellan, welan, and κ-carrageenan) are frequently employed for stabilization. This stabilization is accomplished through mechanisms such as steric repulsion and electrostatic stabilization, which form a protective layer around AuNPs. These stabilizing polymers act as molecular spacers in nanoparticle-based FRET sensing, enabling the precise regulation of the molecular distance between the acceptor and donor fluorophore molecules. This regulation enhances the efficiency and sensitivity of FRET assays. By modifying the length and flexibility of the spacer polymer, researchers can adjust the spacing between fluorophores, ensuring effective energy transfer and the accurate detection of target molecules. However, there is a limited understanding of the role and broad application of these molecular spacers in nanoparticle-mediated FRET-based sensing of various analytes. Consequently, this review explores different fundamental aspects of FRET, polymeric stabilization of gold nanoparticles, and various polymeric spacers in FRET-based sensing, along with the recent advancements and challenges associated with this approach.
在基于荧光共振能量转移（FRET）的传感中，分析物与金属纳米颗粒之间的相互作用受到纳米颗粒物理化学特性的显著影响，这些特性包括其形状、大小、zeta电位、表面连接的配体、掺杂、介质的pH值、颗粒表面粗糙度和晶格结构（原子排列）。在合成过程中，为了避免金纳米颗粒（AuNPs）的聚集，合成聚合物（包括聚乙二醇、聚乙烯亚胺和聚乙烯吡咯烷酮）和天然聚合物（如壳聚糖、淀粉、结冷胶、韦兰胶和κ-卡拉胶）经常被用于稳定化。这种稳定化是通过空间排斥和静电稳定等机制实现的，这些机制在AuNPs周围形成了一层保护层。这些稳定化聚合物在基于纳米颗粒的FRET传感中充当分子间隔物，能够精确调节受体和供体荧光团分子之间的分子距离。这种调节提高了FRET检测的效率和灵敏度。通过改变间隔聚合物的长度和柔韧性，研究人员可以调整荧光团之间的间距，确保有效的能量转移和目标分子的准确检测。然而，人们对这些分子间隔物在纳米颗粒介导的基于FRET的各种分析物传感中的作用和广泛应用了解有限。因此，本综述探讨了FRET的不同基本方面、金纳米颗粒的聚合物稳定化以及基于FRET传感中的各种聚合物间隔物，以及与该方法相关的最新进展和挑战。
