Pongsak Wattanacharoonroj. การศึกษาการตรึงเอนไซม์บนขั้วอิเล็กโทรดของไบโอเซนเซอร์โดยเทคโนโลยีโซลเจล. Master's Degree(วิศวกรรมเคมี). มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี. สำนักหอสมุด.. : King Mongkut's University of Technology Thonburi, 2552-10-17.
Abstract:
In this work we studied the immobilization of acetylcholinesterase (AChE) enzyme with the
electrochemical mediator 7, 7, 8, 8-Tetracyanoquinodimethane (TCNQ) on the carbon electrode by
Sol-Gel Technology for the detection of organophosphorus pesticides and dichlorvos (DDVP). The
determination of the concentration of DDVP was the decrease of AChE activity with the substrate
acetylthiocholine (ACTh) by the inhibition of DDVP. The thin films coated by
methyltrimethoxysilane (MTMOS) were transparent and crack free. The electrode immobilized
AChE I mMyielded anodic peak potentials (Epa) around +150 mV vs. Ag/AgCI reference electrode
analyzed by cyclic voltammograms. The electrode showed a linear response for the ATCh substrate
in the range of s.oeio" and 1.0xl0?3 M with amperometric analysis at +150 mY. The values of
Michaelis Menten (KM) and the sentivity (S) for the films coated with molar ratio of MTMOS to
water at R = 4 and 8 were KM = 2.86, 1.53 mM and S = 0.34, 0.28 mAIM respectively. The results
demonstrated that at R = 8, the diffusion was less and, consequently, more enzyme activity was
obtained. The reproducibility measured by the response ofcurrent of the electrodes' with R = 4 and 8
were 313.7 nA ? 6.7 % and 251.1 nA ? 5.1 (number of electrodes = 10). The linear range of
detection for dichlorvos concentrations was in the range of lxl0-11 to lxlO-7 M.