A Water-Dispersible Carboxylated Carbon Nitride Nanoparticles-Based Electrochemical Platform for Direct Reporting of Hydroxyl Radical in Meat

Abstract

In this paper, carboxylated carbon nitride nanoparticles (carboxylated-g-C3N4 NPs) were prepared through a one-step molten salts method. The synthesized material was characterized by transmission electron microscope (TEM), Fourier transform-infrared spectra (FTIR), and X-ray photoelectron spectroscopy (XPS), etc. An electrochemical sensor based on single-stranded oligonucleotide/carboxylated-g-C3N4/chitosan/glassy carbon electrode (ssDNA/carboxylated-g-C3N4/chitosan/GCE) was constructed for determination of the hydroxyl radical (•OH), and methylene blue (MB) was used as a signal molecule. The sensor showed a suitable electrochemical response toward •OH from 4.06 to 122.79 fM with a detection limit of 1.35 fM. The selectivity, reproducibility, and stability were also presented. Application of the sensor to real meat samples (i.e., pork, chicken, shrimp, and sausage) was performed, and the results indicated the proposed method could be used to detect •OH in practical samples. The proposed sensor holds a great promise to be applied in the fields of food safety.

Dimethyl Sulfoxide: An Ideal Electrochemical Probe for Hydroxyl Radical Detection

“…An interference experiment with a strong oxidant (KMnO 4 ) has also been performed (Figure S9), and the result shows that KMnO 4 has no interference to • OH determination by using DMSO as the probe. Benefiting from the DMSO probe, a highly selective and convenient • OH determination method was established, and its sensitivity is also comparable or even better than some of reported electrochemical biosensors ,− , and electrochemical sensors. ,− ,, …”

“…The selectivity of electrochemical detection can be improved by the introduction of specific recognition elements. For example, an electrochemical sensor based on cerium oxide nanomaterials with enzyme-mimetic property was developed for the determination of • OH, but the interferences from other ROS ( 1 O 2 , O 2 •– , and ClO – ) cannot be excluded. ,− Biological recognition elements (antibodies, enzymes, DNA, or aptamers) have also been employed for the electrochemical determination of • OH. ,− However, the time-consuming modification processes are needed to prepare these electrodes, and the recognition elements are also expensive and easily deactivated in the storage. Hence, a simple, selective, and sensitive electrochemical method is still urgently needed to achieve rapid quantification of • OH in aqueous solution.…”