“…More important, upon recognition of targets, NA probes form characteristic higher‐order conformational changes through hydrogen bonding, electrostatic interactions, shape effect, aromatic ring and/or base pairs aggradation, which allow them to open up a vast repertoire of target recognition and signal transduction patterns. For instance, NA probes have recently been incorporated into paper‐based analytical platforms for detecting nearly all chemical and biological entities, such as metal ions (J. Chen, Zhou, & Wen, ), NAs (Restaino & White, ), microRNA (Kalogianni, Kalligosfyri, Kyriakou, & Christopoulos, ), amino acids (Kaspar, Dettmer, Gronwald, & Oefner, ), polypeptide (Cao et al, ), protein complex (Saha & Jana, ), polysaccharides (S. Wang et al, ), carbohydrate (Yang et al, ), small organic compounds (Conzuelo et al, ), virus particles (Teengam, Siangproh, Tuantranont, Henry et al, ), bacteria (Burlage & Tillmann, ), and organelles and surface markers of cells (Shah, Kaushik, Zhu, Zhang, & Li, ).…”