Table 1.

Genetically-encoded Zn²⁺ sensors

Sensor	Sensor Type a	DR b-d	Kd’ e	Targeted probes f	Ref
ZapCY1	FRET (ECFP/Cit)	2.66 b	17 pM	Cytosol, ER, Golgi, MM	[5, 13, 21]
ZapCmR1.1	FRET (Clover/mR2)	1.5 b	ND	Cytosol, nucleus	[127]
ZapCY2	FRET (ECFP/Cit)	1.4 b	811 pM	Cytosol	[5]
ZapCV2	FRET (ECFP/cpV)	2.1 b	5.3 nM	Cytosol	[22, 119]
ZapCmR2	FRET (Clover/mR2)	1.4 b	ND	Cytosol, nucleus	[127]
ZapCV5	FRET (ECFP/Cit)	1.5 b	300 nM	Cytosol	[22]
eCALWY-1	FRET (Cer/Cit)	1.6 b	2 pM	Cytosol, SV	[7]
redCALWY-1	FRET (mOr/mCh)	1.1 c	12.3 pM	Cytosol	[128]
eCALWY-2	FRET (Cer/Cit)	1.6 b	9 pM	Cytosol	[7]
eCALWY-3	FRET (Cer/Cit)	1.6 b	45 pM	Cytosol	[7]
eCALWY-4	FRET (Cer/Cit)	1.83 b	164 pM	Cytosol, SV, MM, ER	[7, 19, 21]
redCALWY-4	FRET (mOr/mCh)	1.2 c	234 pM	Cytosol	[128]
eCALWY-5	FRET (Cer/Cit)	1.3 b	1.8 nM	Cytosol	[7]
eCALWY-6	FRET (Cer/Cit)	1.3 b	2.9 nM	Cytosol, ER	[7, 19]
eZinCh-1	FRET (Cer/Cit)	ND	8.2 μM	SV	[7]
eZinCh-2	FRET (Cer/Cit)	2.06 b	103 pM	Cytosol, ER, MM, SV	[20, 21]
ZnT72R	FRET (mNG/mR2)	1.4 c	56 μM	Cytosol, SV	[23]
BLCALWY-1	FRET/BRET (NL/Cer/Cit)	ND	4.2 pM		[27]
BLZinCh-1	FRET/BRET (NL/Cer/Cit)	1.25 c	160 pM	Cytosol	[27]
BLZinCh-2	FRET/BRET (NL/Cer/Cit)	1.29 c	117 pM	Cytosol	[27]
BLZinCh-3	FRET/BRET (NL/Cer/Cit)	1.67 c	15.6 pM	Cytosol	[27]
GZnP1	Single FP (cpGFP)	2.6 b	58 pM	Cytosol, MM, PM	[31]
GZnP2	Single FP (cpGFP)	4.5 b	352 pM		[32]
mCherry-GZnP2	Ratiometric (cpGFP/mCh)	ND	ND	Cytosol, IMS, MM	[32]
GZnP3	Single FP (cpGFP)	11 b	1.3 nM	Cytosol, SV, endosome, lysosome	[32]
ZnGreen1	Single FP (mTFP1)	2.5 c	633 nM	Cytosol, cell surface	[34]
ZnGreen2	Single FP (cpTFP1)	ND	20 μM		[34]
ZnRed	Single FP (mApple)	2.5 c	166 nM 20 μM	Cytosol, nucleus	[34]
ZIBG1	Single FP (GFP)	1.6 d	2.81 μM	Cell surface	[36]
ZIBG2	Single FP (cpGFP)	1.8 d	282 nM	Cell surface	[36]

^aFluorescent proteins: Cit = Citrine; mR2 = mRuby2; cpV = cpVenus173; Cer = Cerulean; mOr = mOrange; mCh = mCherry; mNG = mNeonGreen; NL = NanoLuc

^bReported in situ dynamic range (DR) in cytosol

^cEstimated in situ DR in cytosol

^dEstimated in situ DR at cell surface

^eIn vitro K_d’ determined at pH 7.4

^fMM = mitochondrial matrix; IMS = mitochondrial intermembrane space; SV = secretory vesicle