Amperometric detection pesticides

Y. Lin, F. Lu and J. Wang, Disposable carbon nanotube modified screen-printed biosensor for amperometric detection of organophosphorus pesticides and nerve agents, Electroanalysis, 16 (2004) 145-149. 

Another class of enzymes that has found wide application in the biosensor field in the last decades is that of the cholinesterases which have been mainly used for the detection of pesticides. For the amperometric detection of cholinesterase activity, both the substrates acetylcholine and acetylthiocholine have been extensively used [6-9], the latter being preferred because this avoids the use of another enzyme, choline oxidase, which is usually coupled with acetylcholinesterase. However, the amperometric measurement of thiocholine, produced by... 

Most of the inhibition bioassays or biosensors for organophosphate and carbamate pesticides are based on the amperometric detection of the enzymatic product of the reaction. 

Some applications of amperometric biosensing strategies for pesticide detection in real or spiked food samples have been recently reported. Most of the applications have been developed for vegetable matrices. Different formats of biosensors have been used disposable screen-printed choline oxidase biosensors [23] using AChE in solution were utilized to detect pesticides in real samples of fruit and vegetables. 

Baumner, AJ. and R.D. Schmid (1998). Development of a new immunosensor for pesticide detection a disposable system with liposome-enhancement and amperometric detection. Biosens. Bioelectron., 13 519-529. 

Liu, G., Lin, Y. (2006). Biosensor based on self-assembling acetylcholinesterase on carbon nanotubes for flow injection/ amperometric detection of organophosphate pesticides and nerve agents. Anal. Chem. 78 835 3. 

Ghosh, D., Dutta, K., Bhattacharyay, D. and Sarkar, P. (2006) Amperometric detection of pesticides using polymer electrodes. Environ. Monit. and Assess., 119, pp. 481-489. 

Rao et al. reported on the separation and amperometric detection of several V-methyl carbamate pesticides using diamond electrodes [63]. The... 

The association between amperometric detection and FIA system in natural water samples has been reported for the analysis of different pesticides from river, lake, and estuary [92-97]. FIA amperometry was utilized to quantify ethiofencarb, a systemic carbamate used in agriculture to control parasites, in acetate buffer solution, at pH 5.0 [97]. Using a glassy carbon electrode potentiostated at 0.75 V (vs. Ag/AgCl), the pesticide was oxidized over a concentration range from 1.0 X 10 to 1.0 x 10 mol 1 and presented a detection limit of 1.0 x 10 mol 1 . By inhibition of the activity of selected enzymes and immobilized on surface of different detectors, biosensors can also be used in the analysis of pesticides [98-100]. 

Wei, Y., Y. Li, Y. Qu et al. 2009. A novel biosensor based on photoelectro-synergistic catalysis for flow-injection analysis system/amperometric detection of organophosphorous pesticides. Anal. Chim. Acta 643 13-18. 

Liu T, Su HC, Qu XJ, Jn P, Cni L, Ai SY (2011) Acetylcholinesterase biosensor based on 3-carboxyphenylboronic acid/rednced graphene oxide-gold nanocomposites modified electrode for amperometric detection of organophosphoms and carbamate pesticides. Sensor Actual B Chem 160(1) 1255-1261. doi 10.1016/j.snb.2011.09.059... 

Gong JM, Guan ZQ, Song DD (2013) Biosensor based rai acetylcholinesterase immobilized onto layered double hydroxides for flow injection/amperometric detection of organophosphate pesticides. Biosens Bioelectron 39(l) 320-323. doi 10.1016/j.bios.2012.07.026... 

Du D, Huang X, Cai J, Zhang A (2007) Amperometric detection of triazophos pesticide using acetylcholinesterase biosensor based on multiwall carbon nanotube-chitosan matrix. Sensor Actuat B Chem 127 531-535... 

Because process mixtures are complex, specialized detectors may substitute for separation efficiency. One specialized detector is the array amperometric detector, which allows selective detection of electrochemically active compounds.23 Electrochemical array detectors are discussed in greater detail in Chapter 5. Many pharmaceutical compounds are chiral, so a detector capable of determining optical purity would be extremely useful in monitoring synthetic reactions. A double-beam circular dichroism detector using a laser as the source was used for the selective detection of chiral cobalt compounds.24 The double-beam, single-source construction reduces the limitations of flicker noise. Chemiluminescence of an ozonized mixture was used as the principle for a sulfur-selective detector used to analyze pesticides, proteins, and blood thiols from rat plasma.25 Chemiluminescence using bis (2,4, 6-trichlorophenyl) oxalate was used for the selective detection of catalytically reduced nitrated polycyclic aromatic hydrocarbons from diesel exhaust.26... 

MWNTs favored the detection of insecticide from 1.5 to 80 nM with a detection limit of InM at an inhibition of 10% (Fig. 2.7). Bucur et al. [58] employed two kinds of AChE, wild type Drosophila melanogaster and a mutant E69W, for the pesticide detection using flow injection analysis. Mutant AChE showed lower detection limit (1 X 10-7 M) than the wild type (1 X 10 6 M) for omethoate. An amperometric FIA biosensor was reported by immobilizing OPH on aminopropyl control pore glass beads [27], The amperometric response of the biosensor was linear up to 120 and 140 pM for paraoxon and methyl-parathion, respectively, with a detection limit of 20 nM (for both the pesticides). Neufeld et al. [59] reported a sensitive, rapid, small, and inexpensive amperometric microflow injection electrochemical biosensor for the identification and quantification of dimethyl 2,2 -dichlorovinyl phosphate (DDVP) on the spot. The electrochemical cell was made up of a screen-printed electrode covered with an enzymatic membrane and combined with a flow cell and computer-controlled potentiostat. Potassium hexacyanoferrate (III) was used as mediator to generate very sharp, rapid, and reproducible electric signals. Other reports on pesticide biosensors could be found in review [17],... 

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