Electroanalytical Applications Based on Carbon Nanotube/Prussian Blue Screen-printable Composite

Abstract

A single step fabrication process of carbon nanotube/Prussian Blue (CNT/PB) paste electrodes based on screen printing technology has been studied as an amperometric sensor for the determination of hydrogen peroxide and free chlorine. Compared to the classical carbon paste (CP) electrode, the CNT paste electrode greatly enhanced the response in the presence of hydrogen peroxide due to the electrocatalytic activity of the CNT. Based on the CNT/binder paste, PB was also incorporated into a network of CNT paste and characterized. The best electroanalytical properties of PB-mixed sensors to hydrogen peroxide were obtained with PB ratio of 10 wt % composition, which showed fast response time (t90 ≤ 5 s; 0.2 -0.3 mM), low detection limit of 1.0 µM, good linear response in the range from 5.0 × 10 -5 -1.0 × 10 -3 mol L -1 (r 2 = 0.9998), and high sensitivity of -8.21 µA mM -1 . In order to confirm the enhanced electrochemical properties of CNT/PB electrode, the sensor was further applied for the determination of chlorine in water, which exhibited a linear response behavior in the range of 50 -2000 ppb for chlorine with a slope of 1.10 µA ppm -1 (r 2 = 9971).

Application of Prussian Blue in Electrochemical and Optical Sensing of Free Chlorine

“…In particular, electrochemical investigations of the glass|FTO|PB sensor as well as optical investigation of the glass|FTO|PW-PB electrode showed that the sensitivity of PB towards FCL is based on FCL-caused oxidation of PW, i.e., PB catalyses the reduction in FCL through the PW form. The glass|FTO|PB sensor displayed linear dependency between FCL concentration and the reduction current in a wide concentration range from 1.7 to 99.2 μmol L −1 of FCL with a sufficient sensitivity of ~0.8 µA cm − 2 μmol −1 L similar to other PB-based amperometric FCL sensors reported [ 45 , 46 , 47 ] and appropriate for FCL concentration monitoring in disinfected water. The main advantage of the sensor developed in this research is its high selectivity towards FCL as chlorate, perchlorate and nitrate ions induce only negligible amperometric response under the working conditions of the sensor.…”

“…There are several articles covering the application of Prussian blue (PB) for the electrochemical detection of FCL [ 45 , 46 , 47 ]. Shim et al used carbon nanotube/Prussian blue screen-printed composite for the amperometric detection of FCL [ 45 ].…”

“…There are several articles covering the application of Prussian blue (PB) for the electrochemical detection of FCL [ 45 , 46 , 47 ]. Shim et al used carbon nanotube/Prussian blue screen-printed composite for the amperometric detection of FCL [ 45 ]. This composite showed linear response behaviour covering the range of FCL concentrations being used for the disinfection of drinking water.…”

“…Although there are several articles that suggest employing PB redox transitions as a means for quantitative FCL analysis [ 45 , 46 , 47 ], we believe that more in-depth research is lacking before considering the possible practical application of a PB-based FCL sensor in a real-life sample analysis. Therefore, we regard the defining response of the sensor to highly oxidative species, which are often present in FCL solutions as pollutants ( and ), as a novelty.…”