Immobilization of DNA on a glassy carbon electrode based on Langmuir–Blodgett technique: application to the detection of epinephrine

Abstract

A double-stranded (ds) DNA-octadecylamine Langmuir-Blodgett film was attached to the surface of glassy carbon electrode (GCE) to create a novel voltammetric sensor (DNA-LB/GCE) for epinephrine (EP). Atomic force microscopy and electrochemical impedance spectroscopy were employed to study the characteristic of the DNA-LB film. The electrochemical behavior of EP at the modified electrode was investigated in pH 6.0 phosphate buffer solutions by cyclic voltammetry and amperometric methods. Compared with bare GCE, the DNA-LB/GCE sensor demonstrated an electrocatalytic effect on the oxidation of EP. In addition, the sensor shows excellent selectivity for EP detection, being free of interference from excess ascorbic acid and uric acid, and the method was also applied successfully to detect EP in the human urine samples.

Electrochemical characterization of poly(fuchsine acid) modified glassy carbon electrode and its application for simultaneous determination of ascorbic acid, epinephrine and uric acid

“…The detection limits (S/N = 3) were determined to be 0.009, 0.01 and 0.03 μmol L −1 for AA, EP, and UA, respectively. These were much lower than those previously reported for the simultaneous detection of AA, EP, and UA [15][16][17][18][19][20][21][22][23]. The anodic peak currents of AA, EP, and UA were reduced to 97.9%, 98.7% and 97.35% of the initial responses, respectively, after 40 consecutive CV measurements in the same condition.…”

An Electrochemical Sensor Based on Carbon Nano-Fragments and β-cyclodextrin Composite-Modified Glassy Carbon Electrode for the Determination of Rutin

“…However, the Nyquist plot of β-CD/reCNFs/GCE contains a clear semicircular and a linear feature, and the Rct values increase from 14 (re-CNFs/GCE) to 89 . The result indicates that the Fe(CN) 6 3-/4− probe is difficult to pass through the β-CD film and access the electrode surface for exchanging electrons. This is mainly ascribed to nonconducting β-CD molecules loaded on the surface of re-CNFs, which increased the resistance of interfacial charge transfer.…”

“…In addition, the film-forming ability is increased due to the presence of β-CD, and some edges of the sheets are sticking out of the surface, which make a relatively stable rough surface and is generally beneficial in increasing the sensitivity of the sensor. 27 In order to evaluate the electronic property of the modified film, the electrochemical impedance spectroscopy (EIS) of different electrodes in 0.1 mol L −1 KCl solution containing 5.0 × 10 −3 mol L −1 Fe(CN) 6 3-/4− as electrochemical probe was recorded, as shown in Fig. 2.…”

An Efficient Simultaneous Electrochemical Detection of Nanomolar Epinephrine and Uric Acid using Low Temperature Synthesized Nano‐sized Copper Telluride

“…Moreover, in physiological environment, higher concentration of other analytes like dopamine (DA) and ascorbic acid (AA) will exist together with EP and UA which may intervene with each other. The next difficulty is that oxidized products of these molecules are adsorbed at bare electrode surface due to electrode fouling effect which hinders their determination [10]. Hence, to circumvent these difficulties a new technique i. e. chemical modification of the electrode surface has been adopted.…”