A Novel Strategy for Simultaneous Determination of Dopamine and Uric Acid Using a Carbon Paste Electrode Modified with CdTe Quantum Dots

Abstract

A novel CdTe quantum dots‐modified carbon paste electrode (QDMCPE) was fabricated and used to study the electrooxidation of dopamine and uric acid and their mixtures by electrochemical methods. Using square wave voltammetry (SWV), a highly sensitive and simultaneous determination of dopamine and uric acid was explored at the modified electrode. SWV peak currents of dopamine and uric acid increased linearly with their concentrations in the ranges of 7.5×10−8–6.0×10−4 M, and 7.5×10−6–1.4×10−3 M, respectively. Finally this new sensor was used for determination of dopamine and uric acid in some real samples.

Stable CdTe nanocrystals grown in situ in thiol-modified MCM-41 mesoporous silica: Control synthesis and electrochemical detection of Cu 2+

“…A linear relationship between the stripping currents and copper(II) solutions were obtained from 0.5 to 1.7 Â 10 À6 mol L À1 , the linear fitting equation being I p,a (A) ¼ 0.74 Â [Cu 2þ ] À 2.34 10 À7 where I p,a is the anodic peak current and [Cu 2þ ] is concentration of Cu 2þ , with a correlation coefficient of 0.9985 and detection limit 8.2 Â 10 À8 mol L À1 (three times the standard deviation of the blank solution divided by the slope of the analytical curve). This value is comparable with literature reports [44,45] for carbon paste electrodes modified with quantum dot nanocrystals that showed high sensitivity. The analytical characteristics, analytical properties and selectivity achieved by the present electrode are compared in Table 4 with other electrodes reported for copper determination.…”

A Two‐step Strategy for the Selective and Sensitive Detection of Dopamine with Glassy Carbon Electrodes

“…To address the challenges encountered in the electrochemical detection of DA, various electrodes have been fabricated by using metal oxides, nanostructured noble metals, carbon nanostructures, perm‐selective polymer film, etc. . For example, using iron(II) tetrasulfophthalocyanine modified carbon paste microelectrode, Oni et al were able to measure dopamine at a low detection limit of 4.5×10 −7 mol L −1 , but failed to achieve peak separation between dopamine and ascorbic acid .…”

Cd1-xMgxTe semiconductor nanocrystal alloys: Synthesis, preparation of nanocomposites with graphene-based materials, and electrochemical detection of lidocaine and epinephrine

“…In the case of GO, it was also possible to observe the graphene broad emission near 465 nm. The general behavior is identical to that described previously to CdTe nanocrystals grown onto graphene [30]. The shift to longer wavelengths probably occurred due to some agglomeration degree of quantum dots grown over graphene while the quenching was considered a result of charge transfer to graphene.…”

“…Inset Fig. 3d shows the cyclic voltammogram of modified electrode (CPE/QD-GO) exhibiting the anodic peak A1 (+0.85 V) characteristic of the quantum dots, as widely described in the literature for similar systems [30]. In addition, here the oxidation potential shifted to lower values while the …”