“…Due to their different compositions, dimensions, sizes, and shapes, the nanoscaled materials exhibit unique chemical, optical, mechanical, and electronic properties, and they can be easily functionalized with different biomolecules through electrostatic binding, physical adsorption, ligand exchange, biorecognition, and covalent bonding for the construction of diverse nanosensors (Bellan et al, 2011; Ma, Zhang, & Zhang, 2020; Rosi & Mirkin, 2005; Sheehan & Whitman, 2005). Recently, a variety of nanomaterials have been employed for the development of novel single‐molecule fluorescent nanosensors (Y. Han, Chen, et al, 2019; Y. Han, Ye, et al, 2019; B. Li et al, 2020; W. Li et al, 2016; X. Li et al, 2018; Ma, Ren, & Zhang, 2017; Ma, Wei, & Zhang, 2019; Pei et al, 2018; Z. Wu et al, 2019; J. Zhou et al, 2013). The use of functional nanomaterials including quantum dots, gold nanoparticles, upconversion nanoparticles, fluorescent conjugated polymer nanoparticles, nanosheets, and magnetic nanoparticles as fluorescent labels, quenchers, separators, and carriers has greatly improve the sensitivity, accuracy, and applications of single‐molecule detection.…”