Carbon dots and chitosan composite film based biosensor for the sensitive and selective determination of dopamine

Abstract

A simple, sensitive and reliable dopamine (DA) biosensor was developed based on a carbon dots (CDs) and chitosan (CS) composite film modified glassy carbon electrode (CDs-CS/GCE). Under optimal conditions, the CDs-CS/GCE showed a better electrochemical response for the detection of DA than that of the glassy carbon electrode (GCE). The oxidation peak current (Ipa) of DA was linear with the concentration of DA in the range from 0.1 μM to 30.0 μM with the limit of detection as 11.2 nM (3S/N). The CDs-CS/GCE was applied to the detection of DA content in an injection solution of DA with satisfactory results.

Strong adsorption characteristics of a novel overoxidized poly(3,4-ethylenedioxythiophene) film and application for dopamine sensing

“…In order to test the permselectivity, two electroactive probes, Fe(CN) 6 3À and Ru (NH 3 ) 6 3+ , were used [16]. Fig.…”

“…The analytical aspects of the PPY ox , regarding to the film permselectivity to ionic probes, have been investigated [9][10][11][12]. Reports showed small apparent diffusion coefficients for anionic Fe(CN) 6 3À and 3,4-dihydroxyphenylacetate [16] and weak oxidation current response for cationic dopamine and serotonin [11] at the PPY ox -modified electrodes. Therefore, PPY ox usually combined with the other materials to form composites for the determination of catecholamine neutrotransmitters [9][10][11].…”

“…Modification of electrodes with novel materials has been successful to improve the analytical performance of DA [1][2][3][4][5][6][7]. In order to improve the detection selectivity, there were efforts mainly focused on the separation of the oxidation peaks of AA, DA and UA by the use of suitable modified materials [1][2][3]5].…”

“…Besides, the oxidation potentials of AA, DA, and UA usually overlap at conventional electrodes [6], leading to low selectivity and inaccurate determination. Therefore, researchers have dedicated to design novel materials such as conducting polymers [2][3][4], carbon materials [3][4][5][6][7] and electrocatalysts [5], solely or in hybrids, for the convenient and accurate detection of DA alone or in the presence of AA and UA [1][2][3][4][5][6][7].…”

“…Inhibiting the interferences from reaching the sensing surfaces has been considered an effective way to improve DA detection. In this regards, preventing anionic AA and UA with a permselective Nafion film [4] and negatively charge carbon dots [6,7] was investigated, and the obtained electrochemical signals relied on oxidation of DA itself. However, the test solutions contained AA and UA in the ranges of 1-150X excess of DA.…”