Table 1: OP biosensors based on membrane immobilized AChE.

Mode of detectionTransducerEnzyme immobilization methodMinimum detection limitLinearity Substrate/enzyme inhibitorTime of incubation
(min)
Storage stability
(days)
Reference

PotentiometricNylon and cellulose nitrate/pH electrodeCrosslinking0.038 μM
0.077 μM
50 × 103–2.5 × 103
50 × 103–2.5 × 103μM
Trichlorfon, Co-Ral1530
15
[23]

Fiber-opticGlass/sol-gel/polyvinylCrosslinking0.53 μM and 0.023 μM0.54–39.8 and 0.022–0.13 μMCarbaryl, dichlorvos1021[24]

AmperometricHybrid mesoporous silica/Pt electrodeEntrapment1.2 × 10−3μM1.0 × 10−3–0.3 μMDZN-oxon1580[25]

AmperometricMWCNTs/PAN/Pt electrodeAffinity bonds using concanavalin A5.0 × 10−9μM3.6 × 10−8–3.6 × 10−5μMParaoxon20120[26]

AmperometricPAN/AuNPs/Pt electrodeCovalent Bonding0.026 × 10−5μM3.6 × 10−7–3.6 × 10−4μMParaoxon2030[27]

AmperometricCellophane/AuECrosslinking1.45 μM1.45–7.26 μMParaoxon15NR[28]

Dissolved Oxygen metricPoly (2-hydroxyethyl metacrylate)/oxygen electrodeEntrapment0.119 μM0.05–2.62 μMAldicarb52[29]

AmperometricPVA-SbQ/Pt electrodeEntrapment7.2 × 10−5, 0.049 μMNRParaoxon, thifensulfuron methyl3030[30]

AmperometricPolyacrylamide/pH electrodeCrosslinking3.62 × 103μMNRDichlorvos3050[31]

ConductometricSi3N4/Ti layerCrosslinking10 ppbNRZn+, Cd+3020[32]

PotentiometricPore glass/H+ electrodeCrosslinking2 × 10−10 M10−11–10−4 MOP compounds30[33]

ColorimetricH bond N+ membranePhysical adsorption1 mg/mL for omethoate, 0.1 mg/mL for dichlorvos, 2 mg/mL for methamidophos, 0.05 mg/mL for chlorpyrifos, 1.5 mg/mL for carbaryl, and 0.8 mg/mL for pirimicarb.Op compounds15 60[34]

Note: NR: not reported.