GQDs Incorporated CoPc Nanorods for Electrochemical Detection of Dopamine and Uric Acid

Abstract

Dopamine (DA) and uric acid (UA) are biomolecules of great consideration that coexist in human body. It is essential and challenging to detect them simultaneously with high sensitivity. This paper reports a novel electrochemical biosensor based on the nanocomposites of cobalt phthalocyanine (CoPc) anchored with graphene quantum dots (GQDs) for DA and UA detection. The GQDs incorporation on CoPc nanorods with partial end stretching significantly enhances the electrocatalytic activity and promotes the electron transfer rate. Low detection limits of 21 nm for DA and 145 nm for UA have been successfully achieved for the fabricated CoPc/GQDs biosensor. The density‐functional theory proves the enhanced conductivity of CoPc/GQDs and the biomolecule's interaction with the electrode surface. Furthermore, the proposed sensor shows remarkable reproducibility, repeatability, and stability. The fabricated sensor is applied for the simultaneous detections of DA and UA in human urine samples. The excellent performance suggests that the CoPc/GQDs could be a promising and potential candidate for electrochemical sensors to detect DA and UA selectively.

Tunable graphene oxide for the low-fouling electrochemical sensing of uric acid in human serum

“…For example, DA exists as an essential neurotransmitter in the central nervous system, which is associated with behavioural reactions and brain functions, and normally it exists in the range of 0.387–1.548 μM in urine and lower than 130 pM in human whole blood. 4,5…”

“…For example, DA exists as an essential neurotransmitter in the central nervous system, which is associated with behavioural reactions and brain functions, and normally it exists in the range of 0.387-1.548 μM in urine and lower than 130 pM in human whole blood. 4,5 Although many studies have been reported to solve the interference problem, biofouling and chemical fouling of the electrode are regarded as two crucial issues that restrict the practical applications in real sample analysis. 6 Biofouling is caused by the nonspecific adsorption of biomacromolecules (especially proteins) on the electrode surface when used in complex biological fluids (such as blood, saliva, urine, and serum), which could impede the transport of analytes and greatly affect the sensitivity, accuracy, and stability of electrochemical sensors.…”

Recent advances in graphene-based electroanalytical devices for healthcare applications

“…205 Another study used GR quantum dots (GQDs) coupled with cobalt phthalocyanine (CoPc) to modify glassy carbon electrodes (GCEs). 198 The resulting CoPc/GQDs/GCEs showed superior electrocatalytic activity for the simultaneous detection of dopamine (DA) and uric acid (UA) in PBS, outperforming traditional CoPc electrodes. The CoPc/GQDs/GCE showed reversible DA redox peaks and an irreversible UA oxidation peak on CV curves displaying heightened sensitivity and selectivity for simultaneous DA and UA detection.…”