Electrochemical sensors using screen-printed carbon electrode assemblies modified with the beta-cyclodextrin or carboxymethylated beta-cyclodextrin polymer films for determination of tricyclic antidepressive drugs

Screen-printed carbon-based electrodes, operating as working electrodes of the single use commercial three-electrode assemblies, were surface modified with thin films of the condensation polymers of beta -cyclodextrin (beta - CDP) or carboxymethylated beta -cyclodextrin (beta -CDPA) in order to fabri cate disposable electrochemical sensors for determination of tricyclic anti depressive drugs. The azepine and phenothiazine antidepressive drugs were d etermined by using a simple two-step procedure developed which comprised a preconcentration step followed by the differential pulse voltammetry quanti fication. The accumulation properties of the beta -CDPA film appeared to be favorable as compared to those of the beta -CDP film. Concentration calibr ation curves were linear within the range from 1.96 x 10(-7) to 2.75 x 10(- 6) M for individual drugs after 120 s accumulation. The corresponding detec tion limits were from 4 x 10(-8) to 5 x 10(-7) M and 1 x 10(-8) to 1.1 x 10 (-7) M for the beta -CDP and beta -CDPA-modified electrodes, respectively. A sensor featuring the beta -CDPA film-modified electrode was applied succe ssfully for the antidepressant determination in a model serum. (C) 2001 Els evier Science B.V. All rights reserved.