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

“…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-tovolume 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.…”

“…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.…”

ZIF-67C@CeO2 Composite for the Electrochemical Non-Enzymatic Determination of Nitrite in Fish Dry Samples

“…[6][7][8][9] To achieve a larger response current, the primary strategy is to focus on modification of electrode surface. The conventional electrode materials mainly included carbon nanomaterials 10 (graphene, [11][12][13] fullerene, 14 carbon nanotubes 15,16 ), conducting polymers 17 and metallic nanoparticles (gold, 18,19 platinum, 20 palladium, 21,22 titanium 23 ), metal oxides [24][25][26] and hydroxides. 27,28 In recent years, MOF-derived electrode modification materials have gradually become a popular research topic.…”