Figure 6.

(A) A fluorescent sensor for intracellular Zn²⁺ prepared from immobilizing the Zn-sensitive DNAzyme carrying a TP fluorescent dye onto the AuNPs. Reproduced from Yang, C.; Yin, X.; Huan, S.-Y.; Chen, L.; Hu, X.-X.; Xiong, M.-Y.; Chen, K.; Zhang, X.-B. Anal. Chem. 2018, 90, 3118–3123 (ref 148). Copyright 2018 American Chemical Society (B) A metal sensor prepared by coupling the GF with metal-sensitive DNAzymes. Reproduced from Fang, X.; Liu, Y.; Jimenez, L.; Duan, Y.; Adkins, G. B.; Qiao, L.; Liu, B.; Zhong, W. Anal. Chem. 2017, 89, 11758–11764 (ref 149). Copyright 2017 American Chemical Society. (C) The working mechanism of the aptazyme–AuNP sensor for fluorescent detection of intracellular ATP. Reproduced from Yang, Y.; Huang, J.; Yang, X.; Quan, K.; Wang, H.; Ying, L.; Xie, N.; Ou, M.; Wang, K. Anal. Chem. 2016, 88, 5981–5987 (ref 152). Copyright 2016 American Chemical Society. (D) Detection of miRNAs in living cells using AuDH/Mn+/H-mediated dual signal amplification. Reproduced from Meng, X.; Zhang, K.; Dai, W.; Cao, Y.; Yang, F.; Dong, H.; Zhang, X. Chem. Sci. 2018, 9, 7419–7425 (ref 153), with permission of The Royal Society of Chemistry