Construction of polythiophene-derivative films as a novel electrochemical sensor for highly sensitive detection of nitrite

Abstract

Herein, a novel, convenient, and highly selective electrochemical sensor for determination of nitrite based on a polythiophenederivative film-modified glassy carbon electrode (GCE) was established. In this work, 2,5-di-thiophen-3-yl-thiazolo [5,4-d]thiazole (DTT), a novel thiophene derivative, was synthesized and used to form an original and excellent polymer film (PolyDTTF) on GCE through one-step electropolymerization for the first time. The modified electrodes were characterized by electron microscopy (SEM), Fourier transform infra-red spectroscopy (FT-IR), UV-visible spectra, Raman spectroscopy, and electrochemical technologies, in which the electrochemical sensor based on PolyDTTF was successfully constructed and demonstrated a significant electrocatalytic effect on nitrite. The influence of pH value, electrodeposition scanning times, scanning speed, and potential on the electrochemical behavior of nitrite were investigated in detail. Furthermore, the nitrite sensor exhibits excellent responses proportional to nitrite concentrations (R 2 = 0.9972) over a concentration range of 5.5 × 10 −9 ~3.5 × 10 −5 M with a detection limit (LOD) of 2 nM, and has extremely good anti-interference ability for nitrite detection. This proposed sensor can be used to detect nitrite in actual samples, opening the possibility for applications in the food industry and environmental analysis.

One-Step Electropolymerization of Polythiophene Derivative Film for Photoelectrochemical Detection of Chlorpyrifos

“…Synthesis of thiophene monomer S 2 TTz.-In this work, thiophene monomer S 2 TTz was prepared based on the previous literature with some modifications. 35,36 2-thiophenecarboxaldehyde (1.01 g, 9.0 mmol) and dithiooxamide (0.48 g, 4.0 mmol) were dispersed in DMF (50 ml), then the prepared solution was heated under reflux for 6 h. Next, the reaction mixture was filtered and washed through DMF and THF sequentially after cooling to 80 °C. After drying, the obtained powder was named S 2 TTz.…”

Comparison of the analytical performance of two different electrochemical sensors based on a composite of gold nanorods with carbon nanomaterials and PEDOT:PSS for the sensitive detection of nitrite in processed meat products

“…Various conductive nanomaterials and their composites, such as reduced graphene oxide, 32,33 multiwalled carbon nanotubes (MWCNTs), 34,35 metal-organic frameworks, 36,37 metal oxides, 38,39 MXenes, 40,41 and layered double hydroxides, 42 have been employed for nitrite detection to obtain a better current response than conventional electrodes. All these types of nanomaterials can be composited with conductive polymers, e.g., poly (3,4dioxythiophene):polystyrenesulfonate (PEDOT:PSS), 43,44 polypyrrole, 45 polythiophene, 46 and polyaniline, 47,48 to enhance electrode conductivity. Moreover, gold nanorods (AuNRs), as a type of gold nanoparticle, have been widely employed as modiers in electrochemical sensing platforms due to their good biocompatibility, 49,50 high surface area, 51,52 and fast electron transfer ability, 53,54 which could provide efficient mass transport properties to the electrode surface.…”