DNA-modified electrode has been used for the highly selective and sensitive Ru(bpy)32+ electrogenerated chemiluminescent determination of phenothiazine drugs in urine sample. Double-stranded calf-thymus DNA was immobilized by covalently bonding to a conducting polymer containing a carboxylic group, which was electrochemically polymerized on a glassy carbon electrode with a monomer of thiophene-3-acetic acid. Phenothiazine derivatives were selectively preconcentrated onto the DNA-modified electrode due to their intercalative binding properties with DNA double helix. The phenothiazine derivatives as coreactants were then sensitively detected with the Ru(bpy)32+ electrogenerated chemiluminescence. The present method can detect phenothiazine drugs in the linear range of 1.0 × 10-8 M-1.0 × 10-5 M with detection limits of nanomolar concentration level. Moreover, the interference from ascorbic acid, glutamic acid, and amino acids was almost negligible because of electrostatic repulsion between the negatively charged DNA-modified electrode and anionic interfering species. The present detection method exhibited 95.2% recovery in human urine sample. Therefore, the present method can be applicable for real sample analysis.
Bibliographical noteFunding Information:
This work was financially supported by the Korea Science and Engineering Foundation through the Center for Bioactive Molecular Hybrids (CBMH). H.N. Choi acknowledges the fellowship of the BK 21 program from the Ministry of Education and Human Resources Development.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- General Chemical Engineering