To build a portable and sensitive method for monitoring the concentration of the flavonoid rutin, a new electrochemical sensing procedure was established. By using nitrogen-doped carbonized polymer dots (N-CPDs) anchoring few-layer black phosphorene (N-CPDs@FLBP) 0D-2D heterostructure and gold nanoparticles (AuNPs) as the modifiers, a carbon ionic liquid electrode and a screen-printed electrode (SPE) were used as the substrate electrodes to construct a conventional electrochemical sensor and a portable wireless intelligent electrochemical sensor, respectively. The electrochemical behavior of rutin on the fabricated electrochemical sensors was explored in detail, with the analytical performances investigated. Due to the electroactive groups of rutin, and the specific π-π stacking and cation–π interaction between the nanocomposite with rutin, the electrochemical responses of rutin were greatly enhanced on the AuNPs/N-CPDs@FLBP-modified electrodes. Under the optimal conditions, ultra-sensitive detection of rutin could be realized on AuNPs/N-CPDs@FLBP/SPE with the detection range of 1.0 nmol L⁻¹ to 220.0 μmol L⁻¹ and the detection limit of 0.33 nmol L⁻¹ (S/N = 3). Finally, two kinds of sensors were applied to test the real samples with satisfactory results.

Biomass-derived carbon materials (BDCMs) have garnered numerous research interests due to their conspicuous electrochemical merits, which makes them promising candidates for electrode modification materials in electrochemical sensors. This review focuses on the recent progress in BDCM-based electrochemical sensors. We summarize the main synthesis methods and properties of BDCMs and their electrochemical sensing applications in the detection of environmental pollutants, drugs, and biomolecules. This review also emphasizes the advantages and disadvantages of each preparation method, as well as the limitations in detecting the target substance. Furthermore, this review discusses the current challenges and future prospects for advancing biomass-derived carbon materials-based electrochemical sensors.

To design a new electrochemical horseradish peroxidase (HRP) biosensor with excellent analytical performance, black phosphorene (BP) nanosheets and single-walled carbon nanotubes (SWCNTs) nanocomposites were used as the modifier, with a carbon ionic liquid electrode (CILE) as the substrate electrode. The SWCNTs-BP nanocomposite was synthesized by a simple in situ mixing procedure and modified on the CILE surface by the direct casting method. Then HRP was immobilized on the modified electrode with Nafion film. The electrocatalysis of this electrochemical HRP biosensor to various targets was further explored. Experimental results indicated that the direct electrochemistry of HRP was realized with a pair of symmetric and quasi-reversible redox peaks appeared, which was due to the presence of SWCNTs-BP on the surface of CILE, exhibiting synergistic effects with high electrical conductivity and good biocompatibility. Excellent electrocatalytic activity to trichloroacetic acid (TCA), sodium nitrite (NaNO₂), and hydrogen peroxide (H₂O₂) were realized, with a wide linear range and a low detection limit. Different real samples, such as a medical facial peel solution, the soak water of pickled vegetables, and a 3% H₂O₂ disinfectant, were further analyzed, with satisfactory results, further proving the potential practical applications for the electrochemical biosensor.

Ananas comosus leaves were converted to a porous graphitized carbon (GPLC) material via a high-temperature pyrolysis method by employing iron salt as a catalyst. A cobalt molybdate (CoMoO₄)-and-GPLC composite (CoMoO₄/GPLC) was then prepared by engineering CoMoO₄ nanorods in situ, grown on GPLC. N₂ adsorption–desorption isothermal curves and a pore size distribution curve verify that the proposed composite possesses a porous structure and a large specific surface area, which are favorable for charge and reactant transport and the rapid escape of O₂ bubbles. Consequently, the as-synthesized CoMoO₄/GPLC shows low overpotentials of 289 mV and 399 mV to afford the current densities of 10 mA cm⁻² and 100 mA cm⁻² towards the oxygen evolution reaction (OER), which is superior to many CoMoO₄-based catalysts in previous studies. In addition, the decrease in current density is particularly small, with a reduction rate of 3.2% after a continuous OER procedure for 30 h, indicating its good stability. The excellent performance of the CoMoO₄/GPLC composite proves that the GPLC carrier can obviously impel the catalytic activity of CoMoO₄ by improving electrical conductivity, enhancing mass transport and exposing more active sites of the composite. This work provides an effective strategy for the efficient conversion of waste ananas comosus leaves to a biomass-derived-carbon-supported Co-Mo-based OER electrocatalyst with good performance, which may represent a potential approach to the development of new catalysts for OER, as well as the treatment of waste biomass.

Understanding the extent of cadmium (Cd) contamination and its impact on the food industry and ecosystems is crucial; to this end, electrochemical methods provide sensitive and rapid responses for the in situ detection of heavy metal ions. In this paper, a sensitive Cd²⁺ electrochemical sensor was constructed by using a composite material composed of biomass-derived porous carbon and manganese dioxide (MnO₂/KLSC). The composite was demonstrated to have a porous structure with quasi-cubic MnO₂ particles evenly distributed on the carbon matrix. Using MnO₂/KLSC as the electrode material, a simple electrochemical sensing platform was fabricated for the detection of Cd²⁺. The electrochemical analysis showed that the Cd²⁺ sensor has good performance, with a linear detection range of 0.01–80.0 μmol/L and a detection limit of 9.8 nmol/L. Furthermore, the sensor shows excellent repeatability, reproducibility, and good anti-interference. The sensor was successfully applied to analyze rice and sea water samples, demonstrating satisfactory recovery rates. The good performance of MnO₂/KLSC/GCE can be attributed to the excellent electrical conductivity, enlarged active surface area, and good electron transfer capability.

The persistent presence of pesticide residues in vegetables raises significant concerns for food safety and public health, highlighting the need for sensing platforms that are efficient, affordable, and environmentally friendly while minimizing analysis time and reagent use. In this study, we developed a laser-induced graphene electrode (LIGE) modified with a titanium dioxide–Enteromorpha-derived carbon composite (TiO₂@EDC) for the sensitive electrochemical detection of the herbicide diuron in vegetables. This integrated system streamlines material synthesis, electrode fabrication, and electrochemical analysis into a single, practical platform for food safety monitoring. Under optimized conditions, this sensor exhibited a wide linear detection range of 0.01 µM to 1 mM, with a low limit of detection of 2.99 nM (3 S/N) and a limit of quantification of 9.98 nM (10 S/N). Notably, the sensor demonstrated excellent analytical performance in real vegetable samples by accurately quantifying diuron residues in lettuce, indicating its potential for on-site monitoring of pesticide contamination in food matrices to ensure food safety.