Colorimetric dipstick for assay of organophosphate pesticides and nerve agents represented by paraoxon, sarin and VX

<i>In vitro</i> inhibitory potential of methanolic extract of <i>Celosia argentea</i> var. <i>cristata</i> on tyrosinase, acetylcholinesterase and butyrylcholinesterase enzymes

“…These drugs appear to work best in the early and moderate stages of AD. It has been further suggested that dual inhibition of AChE and BChE enzymes should be one of the objectives in the treatment of cognitive dysfunction associated with AD (Pohanka et al, 2010).…”

Recent advances in biosensors based on enzyme inhibition

“…For instance, pH-FETs was used as transducer with immobilized BChE for the detection of solanaceous glycoalkaloids in the concentration range of 0.1 µM to 0.1 mM (Benilova et al, 2006). In the case of optical biosensors, a chromoionophore sensitive to pH changes was used for nerve agents (Pohanka et al, 2010) or for the pesticide dichlorvos (detection limit of 0.5 mg/L) (Wong et al, 2006). The potentiometric transducer required a low buffer capacity, which could be a problem for application in real samples with high ionic strength, and is characterised by low sensitivity.…”

“…Kucherenko et al, 2012 Heavy metals Aluminum (2.1 µM) Barquero-Quiros et al, 2013 Nerve agents Sarin (7.41 pM), Soman (6.31pM), Tabun Soldatkin et al, 2013Ding et al, 2009Pohanka et al, 2010Del Carlo et al, 2010 acetylthiocholine  Oxidation of thiocholine at electrode modified with nanomaterials  Electrochemical oxidation of thiocholine using mediator  Colorimetric or amperometric detection of thiocholine using Ellman's reagent  Photocurrent generated in presence of thiocholine Liu et al, 2006Dong et al, 2013Chen et al, 2013 indoxylacetate  Optical detection (Vis)  Electrochemical detection Pohanka et al, 2013Pohanka et al, 2012 tyrosine  Amperometric detection of enzymatic product Sima et al 2011, catechol, p-cresol, m-cresol, phenol, p-chlorophenol  Amperometric detection of enzymatic product Shan et al, 2008 reduced form of 1,2 naphtoquinone-4-sulfonate  Chronocoulometric detection Vidal et al 2006 …”

Modified Cholinesterase Technology in the Construction of Biosensors for Organophosphorus Nerve Agents and Pesticides Detection

“…The acetic acid originated from hydrolysis will be marked dark red in the detector. The method is comparable to the Ellman's method but in contrast to it there is an advantage of characteristic coloring which is visible even under the artificial light (Pohanka, et al 2010a). Same as the previous means it can function without any other instrumentation and it offers a simple and rapid semiquantitative evaluation of contamination by cholinesterases inhibitors.…”