Table 3.

Colorimetric G4-based OTA detection methods.

Aptamer (5′-3′)	Chromogenic substrate	LOD	References
d(GATCGGGTGTGGGTGGCGTAAAGGGAGCATCGGACA)	3,3′,5,5′-tetramethylbenzidine	0.023ng/mL	Lin et al., 2018
d(CTGGGAGGGAGGGAGGGAAAAGATCGGGTGTGGGTGGCGTAAAGGGAGCATCGGACACCCGATCTTTTCCCTCCC)	ABTS	1 nM	Lee et al., 2014
d(GATCGGGTGTGGGTGGCGTAAAGGGAGCATCGGACA-)	Gold nanoparticle	20 nM	Yang et al., 2011
d(CTGGGAGGGAGGGAGGGATCGGGTGTGGGTGGCGTAAAGGGAGCATCGGACACCCGATCCC)	3,3′,5,5′-tetramethylbenzidine	2.5 nM	Yang et al., 2012
d(biotin-AAAAAAAAAAAAGATCGGGTGTGGGTGGCGTAAAGGGAGCATCGG ACA)	Gold nanorods	0.9 nM	Tian et al., 2020
d(-NH2-C6-TGGGTAGGGCGGGTTGGGAAAGATCGGGTGTGGGTGGCGTAAAGGGAGCATCGGACA)	ABTS	4.28 pg/mL	Shen et al., 2017