Simultaneous Detection of Dopamine and Uric Acid Using a Poly(l-lysine)/Graphene Oxide Modified Electrode.

Yuehua Zhang,Wu Lei,Yujuan Xu,Xifeng Xia,Qingli Hao

doi:10.3390/nano6100178

Yuehua Zhang, Wu Lei + Show 3 more

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https://doi.org/10.3390/nano6100178

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Abstract

A novel, simple and selective electrochemical method was investigated for the simultaneous detection of dopamine (DA) and uric acid (UA) on a poly(l-lysine)/graphene oxide (GO) modified glassy carbon electrode (PLL/GO/GCE) by differential pulse voltammetry (DPV). The electrochemically prepared PLL/GO sensory platform toward the oxidation of UA and DA exhibited several advantages, including high effective surface area, more active sites and enhanced electrochemical activity. Compared to the PLL-modified GCE (PLL/GCE), GO-modified GCE and bare GCE, the PLL/GO/GCE exhibited an increase in the anodic potential difference and a remarkable enhancement in the current responses for both UA and DA. For the simultaneous detection of DA and UA, the detection limits of 0.021 and 0.074 μM were obtained, while 0.031 and 0.018 μM were obtained as the detection limits for the selective detection of UA and DA, using DPV in the linear concentration ranges of 0.5 to 20.0 and 0.5 to 35 μM, respectively. In addition, the PLL/GO/GCE demonstrated good reproducibility, long-term stability, excellent selectivity and negligible interference of ascorbic acid (AA). The proposed modified electrode was successfully implemented in the simultaneous detection of DA and UA in human blood serum, urine and dopamine hydrochloride injection with satisfactory results.

Highlights

Dopamine (3,4-dihydroxyphenylethylamine, DA) is one of the most important neuro-transmitters that plays an important role in human metabolism [1]
We report an electrochemical analytical method for the fast, simultaneous detection of DA and uric acid (UA) based on a PLL/GO-modified glassy carbon electrode (PLL/GO/GCE)
For the untreated-GO/GCE, a pair of apparent redox peaks is observed at the anodic peak potential of +1.G12O5/GVC(pE,eaakpaCir) aonf adptphaerecnatthreoddoicx ppeeaakkspisotoebnsteiravleadt aatptphreoaxnimodaitceplyea−k0p.o51teVnti(apleoafk+1D.1)2, 5inVdi(cpaetainkgCt)he oxiadnadtiothneacnadthroeddicucpteioank opfotLe-nlytisailnaet, raepsppreocxtiimvealtye.lyTh−0e.5o1xiVda(tpioeankoDns),etinpdoitceantitniagl t(h+e0.o6xVid)aotifonL-laynsdine at trhedeuucntitorenaotfedL‐-lGysOin/eG, rCesEpiesctmivueclyh

Summary

Introduction

Dopamine (3,4-dihydroxyphenylethylamine, DA) is one of the most important neuro-transmitters that plays an important role in human metabolism [1]. Considering the importance of DA in physiology and pathology, it is necessary to develop highly efficient and sensitive methods to detect DA. Many approaches have been investigated to detect DA, including spectrophotometric [3], chemiluminescent [4], fluorescent [5], liquid chromatographic [6], and electrochemical methods [7,8]. Some other important neuro-transmitters, such as epinephrine, norepinephrine, serotonin and so on, always coexist in the central nervous system. In vivo and vitro detection of dopamine with high sensitivity and selectivity is of great significance. Fast scan cyclic voltammetric with carbon-fiber implantable biosensors have been reported for in vivo analysis of DA [10]

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