Electrochemical Determination of Food Preservative Nitrite with Gold Nanoparticles/p-Aminothiophenol-Modified Gold Electrode

Abstract

Due to the negative impact of nitrate and nitrite on human health, their presence exceeding acceptable levels is not desired in foodstuffs. Thus, nitrite determination at low concentrations is a major challenge in electroanalytical chemistry, which can be achieved by fast, cheap, and safe electrochemical sensors. In this work, the working electrode (Au) was functionalized with p-aminothiophenol (p-ATP) and modified with gold nanoparticles (Au-NPs) to manufacture the final (Au/p-ATP-Aunano) electrode in a two-step procedure. In the first step, p-ATP was electropolymerized on the electrode surface to obtain a polyaminothiophenol (PATP) coating. In the second step, Au/p-ATP-Aunano working electrode was prepared by coating the surface with the use of HAuCl4 solution and cyclic voltammetry. Determination of aqueous nitrite samples was performed with the proposed electrode (Au/p-ATP-Aunano) using square wave voltammetry (SWV) in pH 4 buffer medium. Characteristic peak potential of nitrite samples was 0.76 V, and linear calibration curves of current intensity versus concentration was linear in the range of 0.5–50 mg·L−1 nitrite with a limit of detection (LOD) of 0.12 mg·L−1. Alternatively, nitrite in sausage samples could be colorimetrically determined with high sensitivity by means of p-ATP‒modified gold nanoparticles (AuNPs) and naphthylethylene diamine as coupling agents for azo-dye formation due to enhanced charge-transfer interactions with the AuNPs surface. The slopes of the calibration lines in pure NO2− solution and in sausage sample solution, to which different concentrations of NO2− standards were added, were not significantly different from each other, confirming the robustness and interference tolerance of the method. The proposed voltammetric sensing method was validated against the colorimetric nanosensing method in sausage samples.

Enhanced His@AuNCs oxidase-like activity by reduced graphene oxide and its application for colorimetric and electrochemical detection of nitrite

“…On other hand, excessive nitrite could react with amines and convert them to carcinogenic N-nitrosamines, giving rise to severe human diseases, including cancer, diabetes, and neurodegenerative diseases [28][29][30]. Therefore, analytical methods that are capable of detecting trace amounts of NO 2 − are highly desired [31][32][33][34].…”

Recent Advances of Conducting Polymers and Their Composites for Electrochemical Biosensing Applications

“…Nitrite is a precursor of nitroamines, a suspect cancer agent, so its level is regulated at safety levels [ 180 ]. Among various methods, nitrite can be oxidized to nitrate by a gold electrode modified by AuNPs and p -aminothiophenol [ 181 ]. However, ascorbic acid, an endogenous electroactive species, is also detected to cause significant interference and must be removed by ascorbic acid oxidase if the measurement is based on simple amperometry.…”

Current Demands for Food-Approved Liposome Nanoparticles in Food and Safety Sector

“…According to a recent literature survey, liposome nanoparticles were used as a biological sensor for microbial pathogens, food toxins, and pesticides. Although a few nanobiosensors have been developed for various detection strategies, several other nanomaterials are also commonly used as an alternative to liposome nanoparticles for the detection of foodborne pathogens and toxins, including GNPs, gold nanorods, MNPs, quantum dots (QDs), SNPs, and silica nanoparticles ( Leonard et al, 2003 ; Valdes et al, 2009 ; Lopez and Merkoci, 2011 ; Inbaraj and Chen, 2016 ). Generally, although the detection of foodborne pathogens and toxins is performed by exploiting the optical (optical sensors) or electronic (electrochemical sensors) properties of the nanomaterials as their value added characteristics ( Lopez and Merkoci, 2011 ; Inbaraj and Chen, 2016 ), liposome nanoparticles have potential advantages over other kinds of nanoparticles used for various different approaches, including sensing approach because of their biocompatibility and biodegradability ( Hsieh et al, 2002 ; Laridi et al, 2003 ; Were et al, 2003 ).…”

“…Previously, a number of different strategies of using GNP and SNP-based applications have been approved as potential alternatives in food industries for their use as detection biosensors, food fortifiers, enzyme and bacteriocin encapsulators and food stabilizers ( Carbone et al, 2016 ; Fahim et al, 2016 ; Kang et al, 2016 ; Üzer et al, 2016 ). In spite of this, there are numerous other possible uses of liposomes in the food industries, including protection and stability of hypersensitive ingredients, and to improve the adequacy of food preservatives ( Carbone et al, 2016 ; Fahim et al, 2016 ; Üzer et al, 2016 ). Encapsulation of liposome entrapped material has shown a wide range of chemical and environmental stabilities against chemical and enzymatic modifications, including temperature and pH stability.…”