Electrocatalytic oxidation of kojic acid at a reduced graphene sheet modified glassy carbon electrode

Ratiometric electrochemical detection of kojic acid based on glassy carbon modified MXene nanocomposite

The significance of developing a selective and sensitive sensor for quality control purposes is underscored by the prevalent use of kojic acid (KA) in cosmetics, pharmaceuticals, and food items. KA's utility stems from its ability to inhibit tyrosinase activity. However, the instability of KA and its potential adverse effects have created a pressing need for accurate and sensitive sensors capable of analyzing real samples. This research introduces an electrochemical ratiometric sensor designed to accurately detect KA in actual cosmetic and food samples. The ratiometric sensor offers distinct advantages such as enhanced selectivity, reproducibility, and sensitivity. It achieves this by leveraging the ratio between two output signals, thereby producing reliable and undistorted results. The sensor is constructed by modifying a Glassy Carbon Electrode (GCE) with a nanocomposite consisting of Ti3C2 MXene, Prussian blue, and gold nanoparticles. The incorporation of MXene and gold nanoparticles heightens sensitivity and reduces impedance. Meanwhile, the Prussian blue signal diminishes proportionally with increasing KA concentration, forming the basis for the ratiometric sensing mechanism. The outcomes of the study reveal a broad linear range (1-600 μM), a low detection limit (1 μM), and strong selectivity for KA. These findings suggest the sensor's potential efficacy in quality control across cosmetics, pharmaceuticals, and food products.

Current State of Porous Carbon for Wastewater Treatment

Porous materials constitute an attractive research field due to their high specific surfaces; high chemical stabilities; abundant pores; special electrical, optical, thermal, and mechanical properties; and their often higher reactivities. These materials are currently generating a great deal of enthusiasm, and they have been used in large and diverse applications, such as those relating to sensors and biosensors, catalysis and biocatalysis, separation and purification techniques, acoustic and electrical insulation, transport gas or charged species, drug delivery, and electrochemistry. Porous carbons are an important class of porous materials that have grown rapidly in recent years. They have the advantages of a tunable pore structure, good physical and chemical stability, a variable specific surface, and the possibility of easy functionalization. This gives them new properties and allows them to improve their performance for a given application. This review paper intends to understand how porous carbons involve the removal of pollutants from water, e.g., heavy metal ions, dyes, and organic or inorganic molecules. First, a general overview description of the different precursors and the manufacturing methods of porous carbons is illustrated. The second part is devoted to reporting some applications such using porous carbon materials as an adsorbent. It appears that the use of porous materials at different scales for these applications is very promising for wastewater treatment industries.

A simple, but highly sensitive, graphene-based voltammetric sensor for salvianic acid A sodium

A simple, but highly sensitive, electrochemical sensor for the determination of salvianic acid A sodium (SAS) based on reduced graphene oxide (rGO) is reported. The sensor (rGO/GCE(ox)) was prepared by coating an rGO film on the surface of a pre-anodized glassy carbon electrode (GCE(ox)) through a dipping-drying method. The characteristic of the modified electrode was examined by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Compared with bare GCE, GCE(ox) and rGO modified GCE, this sensor exhibited a superior ability for detecting SAS. Under the selected conditions, the reduction current had a good linear relationship with the SAS concentration in the range of 8.0 × 10(-8) - 2.0 × 10(-5) mol L(-1), with a low detection limit of 2.0 × 10(-8) mol L(-1). Furthermore, the method was also successfully applied to detect SAS in medicinal tablets.