Development of an acetylcholinesterase biosensor in organic solvents for the detection of pesticide

Hendricks Richard, (2007) Development of an acetylcholinesterase biosensor in organic solvents for the detection of pesticide. University Malaysia Sabah. (Unpublished)


Download (2MB) | Preview


Acetylcholinesterase (AChE) catalyzed the hydrolysis acetylcholine chloride into thiocholine, acetic acid and chloride ion. Oxidation of acetylthiocholine chloride and also the reaction of indicator, DTNB, with thiocholine will produced signals that can be monitored by a UV -vis spectrophotometer. The thiocholine is reacted with DTNB to produced thionitrobenzoate. Measurement ofthionitrobenzoate is conducted at 412nm by UV -vis spectrophotometer. AChE becomes a target for most pesticides such as the organophosphate, malathion. This will enable the AChE to be used as pesticide detector or biosensor. Three types of reaction media used are acetone, cyclohexane and phosphate. Concentration of acetylthiocholine chloride at 2.5mM gave a high activity for free and immobilized AChE in phosphate reaction medium. Immobilized and free AChE was used for malathion detection. The AChE is catalytically active in the phosphate reaction medium but was inactive in acetone and cyclohexane. Immobilized and free AChE showed similar active in phosphate reaction medium. Malathion totally inhibits free and immobilized AChE at malathion concentration of 0.1mM in phosphate reaction medium. No detection of malathion in acetone and cyclohexane were observed due the inactivation of free and immobilized AChE

Item Type: Academic Exercise
Uncontrolled Keywords: Acetylcholinesterase (AChE), hydrolysis, Oxidation, UV-vis spectrophotometer, DTNB, malathion detection
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: SCHOOL > School of Science and Technology
Date Deposited: 14 May 2014 05:23
Last Modified: 13 Oct 2017 03:50

Actions (login required)

View Item View Item