A Carbon Paste Electrode Modified by Bentonite and l‐Cysteine for Simultaneous Determination of Ascorbic and Uric Acids: Application in Biological Fluids

Abstract

A novel modification of a paste carbon electrode by Bentonite (Bent) and l ‐Cysteine ( l ‐Cyst) was carried out for uric acid (UA) and ascorbic acid (AA) detection and quantification. Morphological and compositional characterization of the electrode surface were carried out using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and energy dispersive X‐ray spectroscopic analysis (EDS). Cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques were used to analyze UA and AA. The obtained sensor shows a good stability, sensibility, selectivity, and regeneration ability. Accordingly, the limit of detection (LOD) is found to be 0.031 μ m and 9.6 μ m for UA and AA, respectively. A good linearity in the range of 0.1 to 100 μ m for UA and 10 to 1000 μ m for AA was obtained. The peak‐to‐peak separation of UA‐AA (Δ E UA‐AA ) was determined to be 330 mV. In addition, the sensor is applied successfully to monitor UA and AA in serum samples.

New Trends in Uric Acid Electroanalysis

“…The latest research is investigating sensors based on carbon nanotubes modified with lanthanum hydroxide (La(OH) 3 ) [112], Zn_MM [113], cobalt phthalocyanine [107] or bentonite (Bent) and L-cysteine [114].…”

Ultrasensitive detection of dopamine using Au microelectrodes integrated with mesoporous silica thin films

“…14 Additionally, recently reported dopamine electrochemical sensors may suffer from a tedious electrode modification process and expensive instruments, though they have excellent detection performance. 15,16 Therefore, development of electrode surfaces with good antifouling capability, stability and detection sensitivity is still highly desirable.…”