Mercuric ion (Hg²⁺) in aqueous media is extremely toxic to the environment and organisms. Therefore, the ultra-trace electrochemical determination of Hg²⁺ in the environment is of critical importance. In this work, a new electrochemical Hg²⁺ sensing platform based on porous activated carbon (BC/Cu₂O) modified with cuprous oxide was developed using a simple impregnation pyrolysis method. Differential pulse anodic stripping voltammetry (DPASV) was used to investigate the sensing capability of the BC/Cu₂O electrode towards Hg²⁺. Due to the excellent conductivity and large specific surface area of BC, and the excellent catalytic activity of Cu₂O nanoparticles, the prepared BC/Cu₂O electrode exhibited excellent electrochemical activity. The high sensitivity of the proposed system resulted in a low detection limit of 0.3 ng·L⁻¹ and a wide linear response in the ranges from 1.0 ng·L⁻¹ to 1.0 mg·L⁻¹. In addition, this sensor was found to have good accuracy, acceptable precision, and reproducibility. All of these results show that the BC/Cu₂O composite is a promising material for Hg²⁺ electrochemical detection.

In this work, a two-dimensional leaf-like framework-L embedded electrochemically reduced graphene oxide (ERGO@ZIF-L) was proposed as an outstanding electrode material for the sensitive electrochemical sensing of benomyl (BM). ZIF-L is surrounded by ERGO, which could effectively ensure the stability and dispersion of ZIF-L. With this unique combination, the prepared ERGO@ZIF-L displayed excellent synergistic characteristics with a large surface area, excellent conductivity, plentiful active sites, and high electrocatalytic properties, thus endowing it with high sensitivity for BM determination. The experimental parameters, such as solution pH, material volume, and accumulation time, were optimized. Under optimal conditions, the BM sensor showed a wide linear range (0.009–10.0 μM) and low-limit detection (3.0 nM). Moreover, the sensor displayed excellent stability, repeatability, and reproducibility, and good anti-interference capability. The method was successfully applied to detect BM in real-world samples.

In this work, TiO₂-MXene/poly (3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) composite was utilized as an electrode material for the sensitive electrochemical detection of baicalein. The in-situ growth of TiO₂ nanoparticles on the surface of MXene nanosheets can effectively prevent their aggregation, thus presenting a significantly large specific surface area and abundant active sites. However, the partial oxidation of MXene after calcination could reduce its conductivity. To address this issue, herein, PEDOT:PSS films were introduced to disperse the TiO₂-MXene materials. The uniform and dense films of PEDOT:PSS not only improved the conductivity and dispersion of TiO₂-MXene but also enhanced its stability and electrocatalytic activity. With the advantages of a composite material, TiO₂-MXene/PEDOT:PSS as an electrode material demonstrated excellent electrochemical sensing ability for baicalein determination, with a wide linear response ranging from 0.007 to 10.0 μM and a lower limit of detection of 2.33 nM. Furthermore, the prepared sensor displayed good repeatability, reproducibility, stability and selectivity, and presented satisfactory results for the determination of baicalein in human urine sample analysis.

Acetaminophen (AC) is one of the most common over-the-counter drugs, and its pollutant in groundwater has attracted more attention due to its serious risk to human health. Currently, the research on AC is mainly focused on its detection, but few are concerned about its removal. In this work, for the first time, nitrogen-doped Soulangeana sepals derived biochar/β-cyclodextrin-Metal-organic frameworks (N-SC/β-CD-MOFs) composite was proposed for the simultaneous efficient removal and detection of AC. N-SC/β-CD-MOFs combined the properties of host-guest recognition of β-CD-MOFs and porous structure, high porosity, and large surface area of N-SC. Their synergies endowed N-SC/β-CD-MOFs with a high adsorption capacity toward AC, which was up to 66.43 mg/g. The adsorption type of AC on the surface of N-SC/β-CD-MOFs conformed to the Langmuir adsorption model, and the study of the adsorption mechanism showed that AC adsorption on N-SC was mainly achieved through hydrogen bonding. In addition, the high conductivity, large specific surface area and abundant active sites of N-SC/β-CD-MOFs were of great significance to the high-performance detection of AC. Accordingly, the sensor prepared with N-SC/β-CD-MOFs presented a wide linear range (1.0–30.0 μM) and a low limit of detection of 0.3 nM (S/N = 3). These excellent performances demonstrate that N-SC/β-CD-MOFs could act as an efficient dual-functional material for the detection and removal of AC.

Following publication, concerns were raised regarding the peer-review process related to the publication of this article