Development of new sol-gel carbon composite electrodes and their application as electrochemical sensors

摘要

Two types of modified electrodes, viz. sol-gel and sol-gel-poly(dimethyldiallylamrnonium chloride (PDMDAAC) carbon composite electrodes, were synthe-sised and characterised. In the latter, PDMDAAC was used as functional polymer entrapped within the sol-gel-carbon material. Both types of electrodes are capable of precon-trating [Fe(CN)6]~(4-) from low-concentrated solutions. The linear concentration range covers almost five orders of magnitude (3.0 x 10~(-7) to 1.0x 10~(-2) M) combining the use of the two types of modified electrodes. The improvement in sensitivity by addition of PDMDAAC was proven by comparison of the calibration plots for both types of modified electrodes showing an enhancement factor of 3.1x 10~3. Detection limits are almost two orders of magnitude better than those obtained for sol-gel carbon composite electrodes. The sensors display good stability and reproducibility and adequate life times.