Electrochemical sensors using screen-printed carbon electrode assemblies modified with the β-cyclodextrin or carboxymethylated β-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 fabricate disposable electrochemical sensors for determination of tricyclic antidepressive drugs. The azepine and phenothiazine antidepressive drugs were determined by using a simple two-step procedure developed which comprised a preconcentration step followed by the differential pulse voltammetry quantification. The accumulation properties of the beta -CDPA film appeared to be favorable as compared to those of the beta -CDP film. Concentration calibration 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 detection 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 successfully for the antidepressant determination in a model serum. (C) 2001 Elsevier Science B.V. All rights reserved.