| Description |
In order to develop an herbicide sensor, yeast, potato, and bovine heart mitochondria were isolated and immobilized onto Toray paper electrodes. Cyclic voltammetry showed two redox peaks at 186 ± 14 mV vs. SCE and -357 ± 24 mV vs. SCE with an E1/2 of -128 mV. Scan rate studies suggested the process was surface limited, and therefore was due to the direct electrochemistry of the mitochondria, and not electrocatalysis. The electrochemistry demonstrated a strong linear dependence on pH similar to that of coenzyme Q10. Cytochrome c and inter-membrane quinones were removed from the mitochondria individually, showing the observed redox couple was due to the vast mitochondrial quinone pool in the membrane. The mitochondria modified electrodes were then exposed to the herbicide parathion, which inhibits Complexes II and V in the electron transport chain. Differential pulse amperometry was used to analyze the degree of inhibition and create a calibration curve. The calibration curve for parathion showed a linear relationship between the current and concentration of parathion with a slope of -0.22 ± 0.03 ual-mg . |
