Highly Sensitive Graphene-Based Electrochemical Sensor for Nitrite Assay in Waters

Abstract

The importance of nitrite ions has long been recognized due to their extensive use in environmental chemistry and public health. The growing use of nitrogen fertilizers and additives containing nitrite in processed food items has increased exposure and, as a result, generated concerns about potential harmful health consequences. This work presents the development of an electrochemical sensor based on graphene/glassy carbon electrode (EGr/GC) with applicability in trace level detection of nitrite in water samples. According to the structural characterization of the exfoliated material, it appears as a mixture of graphene oxide (GO; 21.53%), few-layers graphene (FLG; 73.25%) and multi-layers graphene (MLG; 5.22%) and exhibits remarkable enhanced sensing response towards nitrite compared to the bare electrode (three orders of magnitude higher). The EGr/GC sensor demonstrated a linear range between 3 × 10−7 and 10−3 M for square wave voltammetry (SWV) and between 3 × 10−7 and 4 × 10−4 M for amperometry (AMP), with a low limit of detection LOD (9.9 × 10−8 M). Excellent operational stability, repeatability and interference-capability were displayed by the modified electrode. Furthermore, the practical applicability of the sensor was tested in commercially available waters with excellent results.

Electrochemical Sensors based on Gold–Silver Core–Shell Nanoparticles Combined with a Graphene/PEDOT:PSS Composite Modified Glassy Carbon Electrode for Paraoxon-ethyl Detection

“…The combination of conductive materials between graphene and poly­(3,4-ethylenedioxythiophene)/poly­(styrenesulfonate) (PEDOT:PSS) has been extensively employed to enhance conductivity of modified electrodes. − Graphene has been known as an excellent candidate as electrode modifier due to its great conductivity, high electron mobility, high surface-to-volume ratio, and versatility to be modified as a material composite-based electrode . Furthermore, graphene might be aggregated because of electrostatic and π–π interactions, which can reduce its conductivity.…”

“… 32 − 34 Graphene has been known as an excellent candidate as electrode modifier due to its great conductivity, 35 high electron mobility, 36 high surface-to-volume ratio, 37 and versatility to be modified as a material composite-based electrode. 38 Furthermore, graphene might be aggregated because of electrostatic and π–π interactions, which can reduce its conductivity. PEDOT:PSS could employed to avoid the restacking problem between the graphene layers.…”

Harnessing Graphene-Modified Electrode Sensitivity for Enhanced Ciprofloxacin Detection

“…The major disadvantages of all these so-called traditional tools include the relatively long analysis times and the necessity of well-trained personnel to operate the high-cost equipment. Among the different methods, the electrochemical approach manages to overcome all the above-mentioned inconveniences and to offer a relatively rapid, simple, highly sensitive and economically advantageous alternative [20,21].…”

RF Sensor with Graphene Film for HRP Concentration Detection

“…Sensors are designed for the diagnosis of various type of viruses [20] and cancers (breast, prostate) [21] as well as routine clinical analysis (detection of glucose levels in the serum or drug detection and monitoring [11,22]). For the detection of various bio-molecules, many invasive techniques, such as electro-impedance spectroscopy, enzyme oxidation, time domain reflectometer, and surface plasma resonance, exist [23][24][25][26][27].…”