Table 1.

Recent advances in DNAzyme-based biosensors for metal-ion detection in complex matrices

Analyte	DNAzyme	Sensor class	Limit of detection (LOD)	Sample type
Pb2+	GR-5,138,140,146 17E152	CR	32,138 50,146 and 59.39 pM,140 100 nM152	Water,138,140,152 soil146
Pb2+	GR-5	OF	15 fM148	Water
Pb2+	8–17,144 GR-5145,153	FR	50,144 160,153 and 500 pM145	Water
Pb2+	GR-5	OM	2.12178 and 10 nM177	Water
Pb2+	GR-5,155,171,173 17E,160,169 8–17139,155,157,159,160,167,168,170	EC	4.8,155 17.4,170 and 290 fM,157 2,160 8,159 l5,169 20,173 95,139 and 330 pM,171 1.7141 and 10 nM,167 38 fg mL−1168	Water
Pb2+	17E,172,179 8–17154,183	ECL	200 fM,154 3,179 4.73,183 140 pM172	Water,172,179 soil154
Pb2+	17E	EB	830 pM180	Water
Pb2+	GR-5	LAPS	0.01 ppb185	Water
Pb2+	GR-5	QCM	300 pM182	Water
Pb2+	8–17	RRS	500 pM184	Water
Pb2+	8–17	SERS	70 fM175	Water
Hg2+	E6191–193 MZ,194	CR,142,192 FR,195 EC193,194	4.2,193 and 23 fM,194 5,142 30,195 and 33 pM,192	Water,142 herbs192,195
UO22+	39E	CR,143,196,197 FR,143,198 SERS199	72,199 and 100 fM (FR),143 20 (CR),143 190,198 and 330 pM,197 0.08 μg L−1 196	Water
Ca2+	EtNa	FR	11,200 and 17 μM131	Milk,200 water131
Mg2+	E6	FR	300 pM132	Water
Ni2+	Ni03l,81 NC133	FR,81 ECL133	12.9 μM,81 3.1 nM133	Water
Na+	Ce13d	FR	0.4 mM134	Water
Zn2+	17E	CR	3.5 nM135	Water
Cu2+	CuDD,201–204 10–23,205 CCB206	CR,201,202 FR,203 EC204,205	50 fmol,203 330 fM,205 457 pM,206 1.31,201 5,204 8 nM202	Water
Pb2+, Ag+, Hg2+	8–17	FR	Pb2+: 480 pM, Ag+: 230 pM, Hg2+: 170 pM207	Water

Abbreviations: CCB: Cu²⁺-dependent DNAzyme, CR: colorimetric, CuDD: Cu²⁺-dependent DNA-cleaving DNAzyme, EB: electronic balance, EC: electrochemical, ECL: electrochemiluminescence, FR: fluorometric, LAPS: light addressable potentiometric sensor, NC: DNAzyme sequence source not cited but included, OF: optofluidic, OM: optical measurement, PEC: photoelectrochemical, RRS resonance Rayleigh scattering, SERS: surface enhanced Raman spectroscopy, QCM: quartz crystal microbalance.