Voltammetric determination of 6-thioguanine and folic acid using a carbon paste electrode modified with ZnO-CuO nanoplates and modifier

• A modified carbon paste electrode has been fabricated.
• This electrode reduced the oxidation potential of 6-thioguanine.
• It resolved the voltammetric waves of 6-thioguanine and folic acid.

ZnO-CuO nanoplates and 2-chlorobenzoyl ferrocene, were synthesized and used to construct a modified carbon paste electrode. The electrooxidation of 6-thioguanine at the surface of the modified electrode was studied. Under the optimized conditions, the square wave voltammetric (SWV) peak current of 6-thioguanine increased linearly in the concentration range 0.05 to 200.0 μM and detection limit of 25 ± 2 nM was obtained for 6-thioguanine. The prepared modified electrode exhibits a very good resolution between the voltammetric peaks of 6-thioguanine and folic acid which makes it suitable for the detection of 6-thioguanine in the presence of folic acid in real samples.