Development, Optimization, Characterization, and Application of Electrochemical Biosensors for Detecting Nickel Ions in Food

Abstract

Nickel is naturally present in drinking water and many dietary items, which expose the general population to nickel ingestion. This heavy metal can have a variety of harmful health effects, causing allergies and skin disorders (i.e., dermatitis), lung, cardiovascular, and kidney diseases, and even certain cancers; therefore, nickel detection is important for public health. Recent innovations in the development of biosensors have demonstrated they offer a powerful new approach over conventional analytical techniques for the identification and quantification of user-defined compounds, including heavy metals such as nickel. We optimized five candidate nickel-biosensing receptors, and tested each for efficiency of binding to immobilization elements on screen-printed electrodes (SPEs). We characterized the application of nickel-detecting biosensors with four different cultivated vegetables. We analyzed the efficiency of each nickel-detecting biosensor by potentiostat and atomic absorption spectrometry and compared the results from the sample analytes. We then analyzed the performance characteristics and responses of assembled biosensors, and show they are very effective at measuring nickel ions in food, especially with the urease-alginate biosensor affixed to silver SPEs, measured by cyclic voltammetry (sensitivity—2.1921 µA Mm−1 cm−2 and LOD—0.005 mg/L). Given the many advantages of biosensors, we describe an optimization pipeline approach to the application of different nickel-binding biosensors for public health, nutrition, and consumer safety, which are very promising.

Biopolymers Used for Receptor Immobilization for Nickel-Detection Biosensors in Food

“…Carbon-based electrodes are widely used in electroanalytical investigations for the development of sensors to determine organic and inorganic analytes because of their low cost, good electron transfer kinetics, and biocompatibility [ 36 , 40 ]; moreover, modification of the carbonaceous surface is necessary to improve the electrocatalytic potential for the oxidation of organic and inorganic hydroperoxides. Urease is a nickel-dependent enzyme found in many organisms, including algae, fungi, prokaryotes, and plants.…”

“…A previous study on nickel biosensor development reported that urease affixed to SPEs was effective for nickel detection in food samples [ 36 ]. Using the same dynamic range from the previous study, we furthered the work by optimizing receptor immobilization agents with four biopolymers types and concentrations.…”

“…These results suggest they are good candidate biopolymers in biosensors that are designed for detecting nickel in sample analytes. The advantages of this developed biosensor compared to others include: improved sensitivity for carbon SPE—via changing the biopolymers used (alginate with carrageenan)—compared to the previous study (from 0.1725 to 2.6820) [ 36 ]; and the food-specific linear range that is not present in many studies but has importance for rapid testing, especially in the case of an allergic person. These improvements may be due to the carrageenan that facilitated the development of a compact matrix and immobilized the biomolecules; thus, the porous structure allows efficient diffusion of substrates that promote the urease rate.…”

“…Control experiments were carried out with immobilization of urease with biopolymers in the same condition of measurement but in the absence of nickel. We used the CV technique herein because it was effective in previous work [ 36 ]. Here we use this technique to evaluate sensor performance with different types and concentrations of immobilizing agents on carbon electrodes, which are less expensive than silver electrodes.…”

A novel “off-on” fluorescent probe for the detection of nickel ions and its clinical application

“…Nickel, a widely used transition metal in industrial production, is also an essential micronutrient distributed throughout the human body. It mainly exists as divalent ions and plays a vital role in numerous enzymes ( Genchi et al, 2020 ; Anchidin-Norocel et al, 2021 ). Nickel ions are found in various tissues such as the liver, kidney, spinal cord, brain, heart, cartilage, lung connective tissue, and skin ( Afzali and Mohammadi, 2011 ; Rajivgandhi et al, 2021 ).…”