Nanotube-Boramidic Acid Derivative for Dopamine Sensing

Abstract

A new sensor, based on boramidic acid-bounded MWCNTs (Multi-walled carbon nanotubes), was synthesized in three simple steps. Modification of the sensor surface was accomplished using boric acid in which the boron atom is adjacent to the NH group. Characterization, electrochemical behaviors, and stability of newly modified nanosensor were completed using SEM (scanning electron microscope), TEM (Transmission electron microscope), CV (cyclic voltammetry), EIS (electron impedance), DTA (Differential thermal analysis), and XPS (X-ray photoelectron spectroscopy). SEM and TEM analysis were confirmed the modified surface of the nanosensor. The stability of the newly synthesized sensor was also designated that the initial weight loss occurred between 50-145 degrees C was corresponded to the degradation of both ethylene diamine and boric acid. According to the EIS study, the Nyquist plot of the MWCNTs-NH-B (OH)(2)/GC electrode displayed a 0.435 k omega Rct with a smaller semicircle than the bare GC (6.57 k omega). The electrochemical behavior of dopamine was investigated using cyclic and square wave voltammetry (0.1 M phosphate buffer solution-pH 7.4). The diffusion-controlled process was determined when the oxidation of dopamine was studied. The detection limit of dopamine was found to be 5.1 nM. An actual sample study was done using the developed analytical method, and the detection of dopamine in urine was successfully performed. This study is the first example of boramidic acid-modified multi-walled carbon nanotubes