Accession Number : ADA559618


Title :   Stabilizing Acetylcholinesterase on Carbon Electrodes Using Peptide Nanotubes to Produce Effective Biosensors


Descriptive Note : Master's thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT


Personal Author(s) : Stevens, Todd J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a559618.pdf


Report Date : 22 Mar 2012


Pagination or Media Count : 36


Abstract : A biosensor for the detection of organophosphates in water was created by immobilizing acetylcholinesterase (AChE) on a carbon screen printed electrode using peptide nanotubes (PNT) and Nafion(registered trademark). This sensor was used with acetylthiocholine (ASCh) substrate to detect the inhibitory effects of malathion. The stability of the encapsulated enzyme was measured over 50 days of storage at 4 deg C in a phosphate buffer solution. The oxidation of thiocholine, a product of the enzymatic reaction of ASCh and AChE, was used to measure the activity of the encapsulated enzyme. Cyclic voltammograms were taken in an ASCh and phosphate buffer solution, and the peak oxidation was used to measure the performance of the sensor. Amperometric studies were also conducted at 310 mV vs Ag/AgCl to measure the response of the sensors to ASCh and malathion. This research demonstrates that the use of PNTs and Nafion(registered trademark) allows the sensor to remain stable under these conditions for a much longer period than similar biosensors relying on adsorption alone, losing 17.3% and 14.2%, activity, respectively, after 50 days. Detection limits of as low as 48 nM of malathion were obtained using PNT, and 102 nM using PNT and Nafion(registered trademark).


Descriptors :   *ACETYLCHOLINESTERASE , BIOLOGICAL DETECTION , ELECTRODES , ENZYMES , INHIBITION , MALATHION , THESES


Subject Categories : Biochemistry
      Miscellaneous Detection and Detectors


Distribution Statement : APPROVED FOR PUBLIC RELEASE