Abstract
Here, we introduce the preparation of the hybrid nanocomposite-modified electrode consisting of reduced graphene oxide (RGO) and gold nanoparticles (AuNPs) using the one-step electrochemical method, allowing for the simultaneous and individual detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA). RGO/AuNPs nanocomposite was formed on a glassy carbon electrode by the co-reduction of GO and Au3+ using the potentiodynamic method. The RGO/AuNPs nanocomposite-modified electrode was produced by subjecting a mixed solution of GO and Au3+ to cyclic sweeping from −1.5 V to 0.8 V (vs. Ag/AgCl) at a scan rate 10 mV/s for 3 cycles. The modified electrode was characterized by scanning electron microscopy, Raman spectroscopy, contact angle measurement, electrochemical impedance spectroscopy, and cyclic voltammetry. Voltammetry results confirm that the RGO/AuNPs nanocomposite-modified electrode has high catalytic activity and good resolution for the detection of DA, AA, and UA. The RGO/AuNPs nanocomposite-modified electrode exhibits stable amperometric responses for DA, AA, and UA, respectively, and its detection limits were estimated to be 0.14, 9.5, and 25 μM. The modified electrode shows high selectivity towards the determination of DA, AA, or UA in the presence of potentially active bioelements. In addition, the resulting sensor exhibits many advantages such as fast amperometric response, excellent operational stability, and appropriate practicality.
Highlights
Dopamine (DA) plays a key role in the central nervous, renal, and hormonal systems of human bodies [1]
Electrochemical detection of DA can be disturbed by other biological molecules such as ascorbic acid (AA), and uric acid(UA) [16]
We report a simple electrochemical fabrication of reduced graphene oxide (RGO)/AuNPs nanocomposite
Summary
Dopamine (DA) plays a key role in the central nervous, renal, and hormonal systems of human bodies [1]. Abnormal levels of DA are diagnostic factors of several diseases such as schizophrenia [2], Parkinson’s disease [3], Alzheimer’s disease [4], and Huntington’s disease [5]. A highly sensitive determination of DA levels is needed in the early diagnosis of neurological disorders. Electrochemical methods have a lot of advantages such as simplicity, low cost, short time of operation, high sensitivity, and availability of in-situ monitoring. The high levels of AA can overwhelm the electrochemical signal of DA. The voltammetric response of UA is similar to that of DA, making it difficult to detect DA selectively. To overcome this limitation, several approaches have been developed using the Nanomaterials 2018, 8, 17; doi:10.3390/nano8010017 www.mdpi.com/journal/nanomaterials
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call