The Solvothermal Synthesized La-Doped ZnO Nanorods Modified Electrochemical Sensor for the Determination of Bisphenol A

Abstract

La-doped ZnO nanorods were successfully synthesized by a solvothermal synthesis route using ethanol as the solvent. The morphologies and composition were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). A new electrochemical sensor was fabricated based on the as-synthesized nanorods and the electrochemical behaviors of bisphenol A (BPA) on modified carbon paste electrode (CPE) were investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The experimental results confirmed that La-doped ZnO nanorods exhibit excellent electrocatalytic activity toward the oxidation of BPA. By using CV method, a lower detection limit of 0.1 μM (S/N = 3) with the linear calibration curves over the concentration range 0.4∼90 μM were obtained. Besides, the interference experiments and the actual analysis of BPA were performed. The sensor has potential application in the fields of biomedical and environmental science.Bisphenol A (BPA) [4, 4 -(1-Methylethyliden) bisphenol] is an important phenolic compound with a structure analogous to endocrine hormones, such as estradiol and diethylstilbestrol. That is why BPA shows estrogenic potential, 1 acute toxicity toward aquatic organisms 2 and human cultured cells. 3 In addition, BPA was acknowledged to cause reproductive disorders including decrease of sperm quality in humans, reduction of immune function, impairment of reproduction and so on. 4 Therefore, it is very important to establish a sensitive and simple method for the determination of BPA. Up to now, plenty of strategies such as fluorescence, 5 high performance liquid chromatography, 6 gas chromatography-mass spectrophotometry, 7 electrochemistry 8 and other analytical techniques have been reported to sensitively detect BPA. Among these methods, electrochemically analytical technique, especially chemically modified electrode (CME), is frequently used because of its excellent catalytic activity, physical stability and so on. [9][10][11] Currently, various materials, including molecularly-imprinted polymer, metal composites and nanoparticles, have been used for the construction of CMEs to determine BPA. For example, Ai et al. fabricated a electrochemical sensor for sensitive detection of BPA using cobalt phthalocyanine modified carbon paste electrode and the limit of detection (LOD) was 10 nM. 12 TiO 2 nanotubes and MIPs (polypyrrole), 13 Mg-Al layered double hydroxide, 14 and chitosanFe 3 O 4 15 were also used for the sensitive BPA detection. LODs were estimated to be 2.0 nM, 5.0 nM, and 8.0 nM, respectively. Moreover, tyrosinase based chemical sensor was developed for monitoring BPA with LOD of 20 nM. 16 These results showed that different kinds of modified materials have significant influence on the sensitivity and selectivity of CMEs. According to previous researches, 17,18 the nanoscale metal-oxide plays a vital role in the modification of CME owing to its high specific surface area, good compatibility and stability. Many ele...

Enhanced Electrochemical Sensing Based on Perylenetetracarboxylic Acid Functionalized Carbon Nanohorns Hybrids Modified Electrode

“…BPA, listed as a representative endocrine disrupter with widespread environmental pollution, exhibits estrogenic potential and acute toxicity toward human cultured cells and aquatic organisms. [26][27][28][29][30] Firstly, the detection conditions for BPA were optimized by DPV. As shown in Figure 5A, it's noted that the peak current of BPA gradually increases over the pH range from 5.0 to 7.0.…”

“…Next, the selectivity of the PTCA-CNHs/GCE was also investigated by addition of possible interference [26][27][28][29][30] to 0.8 μM BPA solution. The results show that no interferences were observed for NO 3 − , CO 3 2− , SO 4 2− , Mg 2+ ,Cu 2+ , Pb 2+ , and Fe 3+ (with concentrations 50 times higher than that of BPA).…”

A Very Simple Method for Detection of Bisphenol A in Environmental Water by Heme Signal Amplification

“…Occasionally, bio-recognition elements (including enzymes and antibodies) have been incorporated to improve selectivity of BPA detection via electrochemical methods. In many cases, mediators enhance the sensitivity and selectivity of modified electrodes for BPA detection, 25 for example, graphene, 26,27 gold Nanoparticles, 28 SiO 2 nanospheres, 29 ZnO nanorods, 30,31 carbon nanotubes, 32 carbon materials. 33,34 Noble metal nanostructured materials are known to possess advantageous optical, electrical, thermal conductive and catalytic properties that are highly useful for applications in optical, electronic, and catalytic devices.…”