Acetylcholinesterase Biosensors for Electrochemical Detection of Organophosphorus Compounds: A Review

Table 4

OP biosensors based on sol-gel immobilized AChE.

Mode of detection	Transducer	Enzyme immobilization method	Minimum detection limit	Linearity	Substrate/enzyme inhibitor	Time of incubation; (min)	Storage stability; (days)	Reference
Optical	Sol-gel/TMOS	Encapsulation	0.94 μM; 42.19 μM	3.17–31.48; 14.89–998.40 μM	Naled, Mecarbam	5	30	[65]
Optical	Sol-gel/Glass	Encapsulation	0.098 μM	0.098–0.55 μM	Paraoxon	30	NR	[66]
Amperometric	Silica sol-gel/SPE	Encapsulation	0.024, 0.015, and 0.012 μM	0.01–0.001 μM	Paraoxon, dichlorvos, and chlorpyrifos-ethyl oxon	20	6	[67]
Amperometric	TMOS sol-gel/SPE	Encapsulation	1.0 × 10^−3 μM	1.0 and 3.0 × 10^−3 μM	Dichlorvos	15	NR	[68]
Amperometric	TEOS sol-gel/GCE	Encapsulation	0.008 μM	0.008–0.81 μM	Oxydemeton methyl	20	21	[69]
Optical	Chromo-ionophore/Sol-gel	Encapsulation	2.26 μM	2.26–31.67 μM	Dichlorvos	15	NR	[70]
Amperometric	Al2O3 sol-gel matrix SPE	Adsorption	0.01 μM	0.1–80 μM	Dichlorvos	15	5	[71]
Amperometric	Sol-gel matrix on TCNQ modified SPE	Entrapment	1 × 10^−2,; 8 × 10^−4, and 2 × 10^−2 μM	NR	Carbaryl, carbofuran, and pirimicard	20	45	[72]
Electrochemical	AuNPs-SiSG/GCE	Hydrogen bonds	0.44 μM	NR	Monocrotophos	10	30	[73]
Amperometric	Alumina/sol-gel/sonogel composite/Carbon electrode	Encapsulation	2.5 × 10^−4 μM	0.5 μM	Chlorpyriphos-ethyl oxon	10	50	[74]
Optical	Bromothymol blue/sol-gel	Encapsulation	0.11 μM	0.14–5.70 μM	Chlorpyrifos	8	10	[75]
Amperometric	Zinc oxide/sol-gel/SPE		0.127 μM	0.127–5.010 μM	Paraoxon	10	90	[76]
Amperometric	Silica/sol-gel/Carbon electrode	Encapsulation	3.0 × 10^−4 and 0.47 μM	3.7 × 10^−4–1.8 × 10^−3 and 0.27–4.09 μM	Methyl parathion and acephate	20 and 4	30	[77]
Cyclic Voltametry	Sol-gel/carbon electrode	Entrapment	0.04 ppb for parathion, 47 ppb for monocrotophos	0.1–1.0 ppb	Parathion and monocrotophos	10	NR	[78]

Note: NR: not reported.