Voltammetric behavior of rutin at a boron-doped diamond electrode. Its electroanalytical determination in a pharmaceutical formulation

Copper-Guanosine Nanorods (Cu-Guo NRs) as a Laccase Mimicking Nanozyme for Colorimetric Detection of Rutin

Inspired by laccase activity, herein, Cu-guanosine nanorods (Cu-Guo NRs) have been synthesized for the first time through a simple procedure. The activity of the Cu-Guo NR as the laccase mimicking nanozyme has been examined in the colorimetric sensing of rutin (Rtn) by a novel and simple spectrophotometric method. The distinct changes in the absorbance signal intensity of Rtn and a distinguished red shift under the optimum condition based on pH and ionic strength values confirmed the formation of the oxidized form of Rtn (o-quinone) via laccase-like nanozyme activity of Cu-Guo NRs. A vivid and concentration-dependent color variation from green to dark yellow led to the visual detection of Rtn in a broad concentration range from 770 nM to 54.46 µM with a limit of detection (LOD) of 114 nM. The proposed methodology was successfully applied for the fast tracing of Rtn in the presence of certain common interfering species and various complex samples such as propolis dry extract, human biofluids, and dietary supplement tablets, with satisfactory precision. The sensitivity and selectivity of the developed sensor, which are bonuses in addition to rapid, on-site, cost-effective, and naked-eye determination of Rtn, hold great promise to provide technical support for routine analysis in the real world.

A Review on Recent Advances in the Applications of Boron-Doped Diamond Electrochemical Sensors in Food Analysis

The usage of boron-doped diamond (BDD) material has found to be very attractive in modern electroanalytical methods and received massive consideration as perspective electrochemical sensor due to its outstanding (electro)chemical properties. These generally known facilities include large potential window, low background currents, ability to withstand extreme potentials and strong tendency to resist fouling compared to conventional carbon-based electrodes. As evidence of superiority of this material, couple of reviews describing the overview of various applications of BDD electrodes in the field of analytical and material chemistry has been reported in scientific literature during last decade. However, herein proposed review predominantly focuses on the most recent developments (from 2009 to 2020) dealing with the application of BDD as an advanced and environmental-friendly sensor platform in food analysis. The main method characteristics of analysis of various organic food components with different chemical properties, including additives, flavor and aroma components, phenolic compounds, flavonoids and pesticides in food matrices are described in more details. The importance of BDD surface termination, presence of sp² content and boron doping level on electrochemical sensing is discussed. Apart from this, a special attention is paid to the evaluation of main analytical characteristics of the BDD electrochemical sensor in single- and multi-analyte detection mode in food analysis. The recent achievements in the utilizing of BDD electrodes in amperometric detection coupled to flow injection analysis, batch injection analysis, and high-performance liquid chromatography are also commented. Moreover, actual trends in sample preparation techniques prior to electrochemical sensing in food analysis are referred.