Accurate determination of ascorbic acid (AA, vitamin C), an essential, water‐soluble antioxidant widely found in foods and pharmaceutical products and playing a critical role in human health, is important for clinical diagnosis, pharmaceutical analysis, and food quality control. Therefore, developing electrochemical sensing platforms with high sensitivity, rapid response, low cost, and simple operating principles is essential for the precise and selective determination of AA. In this study, LaBO 3 /g‐C 3 N 4 (B = Mn, Fe, Co) nanocomposites were synthesized via a solution combustion route followed by ultrasonic coupling with graphitic carbon nitride (g‐C 3 N 4 ), and their electrochemical performance toward AA detection was systematically investigated. Comprehensive structural and physicochemical analyses confirmed the generation of highly crystalline perovskite oxides and their successful integration with g‐C 3 N 4 . LaCoO 3 /g‐C 3 N 4 (LCO/GCN) displayed superior optoelectronic and electrochemical properties, exhibiting the highest electrocatalytic activity toward AA oxidation with good selectivity, excellent reproducibility, operational cycling stability over 100 cycles, and successful applicability to real vitamin C samples analyses.
Dopamine (DA) is a key neurotransmitter whose abnormal level fluctuations are implicated in various diseases, rendering highly sensitive and selective detection critical for the early diagnosis and intervention. In this study, a bimetallic CuNi‐BTC (BTC = 1,3,5‐benzenetricarboxylic acid) metal‐organic framework (MOF) served as the carrier for AuPd bimetallic nanoparticles (AuPd NPs); the resultant hybrid was combined with graphene oxide (GO) and subjected to electrochemical reduction, producing an AuPd/CuNi‐BTC/electrochemically reduced GO (AuPd/CuNi‐BTC/ERGO) composite. The regular one‐dimensional rod‐like microstructure of the CuNi‐BTC MOF served as the structural skeleton and contributed to synergistic effects within the composite. It was an ideal carrier for uniformly dispersing the bimetallic nanoparticles, which enhanced the electrocatalytic activity toward DA. Meanwhile, the ERGO imparted high conductivity, enabling rapid interfacial electron transfer. The resulting composite was employed to modify a glassy carbon electrode for DA sensing. Experimental results demonstrated that the sensor exhibited two linear response ranges for DA, from 0.1 to 10.0 μM and from 10.0 to 400.0 μM, with a detection limit of 0.018 μM (S/N = 3) and a sensitivity of 24.53 μA μM −1 cm −2 . In anti‐interference tests, the presence of 10‐fold excess of common interferents (e.g., uric acid, ascorbic acid, and glucose) resulted in a current suppression of less than 10%, suggesting favorable selectivity. The sensor also exhibited acceptable reproducibility (RSD = 2.33%, n = 5) and satisfactory long‐term stability, retaining 102.6% of its initial response after 42 days of storage at 4 °C. When applied to DA detection in urine and commercial DA injection samples, the recoveries ranged from 100.59% to 104.85% (RSD = 1.68%–5.94%), confirming its potential for practical quantitative analysis of DA.
Cell‐based electrochemical biosensors (CBEBs) employ viable cells as recognition, response, or signal‐amplification elements and convert cell‐derived physiological or biochemical changes into electrochemical outputs. By integrating cellular responses such as metabolic remodeling, ion‐channel modulation, oxidative stress, membrane disruption, and apoptosis, CBEBs provide functional biological information that complements conventional assays based on isolated enzymes, antibodies, or aptamers. This capability is particularly relevant to food‐safety screening, where complex matrices and contaminant mixtures may induce combined biological effects that are difficult to assess through single‐analyte detection alone. This review examines the design and application of CBEBs, with emphasis on the relationships among cellular responses, electrochemical transduction, and cell–electrode biointerfaces, and how food‐matrix conditions jointly determine analytical performance. Amperometric, voltammetric, and impedimetric strategies are compared in terms of measurable biological endpoints, matrix sensitivity, and signal interpretability. Mammalian, microbial, immune, stem‐cell‐derived, and engineered cell models are discussed in relation to food‐safety sensing requirements, together with interface‐engineering approaches based on nanomaterials, conductive polymers, hydrogels, 3D scaffolds, and microfluidic systems. Food‐safety studies are prioritized, while selected nonfood examples are considered only where they clarify transferable design principles. Finally, major barriers, including limited cell stability, signal variability, insufficient specificity, matrix interference, and a lack of standardized validation in representative food samples, are critically evaluated. Future progress will require reproducible cell–electrode interfaces, matrix‐aware validation, integrated microfluidic control, and data‐assisted signal interpretation to support robust and portable platforms for effect‐based food‐safety screening.
This study reports the application of a solid bismuth microelectrode array for the determination of cobalt(II) ions by adsorptive stripping voltammetry (AdSV). The electrochemical properties of the proposed sensor were evaluated, highlighting its eco‐friendly nature through the use of nontoxic electrode material. A significant advantage of this procedure is that it requires no surface modification of the working electrode. After optimization of the experimental parameters, including pH of supporting electrolyte, activation conditions, and accumulation potential and time, the sensor exhibited a linear response for Co(II) concentrations ranging from 5 × 10 −10 to 1 × 10 −7 mol L −1 (with an accumulation time of 120 s). The limit of detection was equal to 2.2 × 10 −10 mol L −1 . The repeatability, expressed as relative standard deviation, was 4.7% ( n = 5) for a 2 × 10 −8 mol L −1 of Co(II). The developed procedure was successfully validated using certified reference materials and recovery studies in environmental water samples, confirming its suitability for practical analytical applications.
To achieve high‐precision and high‐sensitivity detection of Pb 2+ in random environments, a novel dual working electrode adaptive compensation and dual signal amplification sensor has been proposed. In a randomly fluctuating environment, one working electrode was modified with the target recognition element and thus generates both signal and noise, whereas the other electrode lacks the target modification and responds only to background noise. Two electrode signals were subtracted to eliminate background noise and achieve adaptive compensation. The imprinted sensor was prepared using chitosan as the functional monomer, followed by immobilization of specific DNA enzymes (DNAzyme) on its surface to construct a DNAzyme‐imprinted dual‐signal amplification sensor. The target Pb 2+ interacted with the imprinting site and DNAzyme respectively, generating a dual signal amplification effect. The feasibility and adaptive compensation performance of the DNAzyme‐imprinted sensor were analyzed, and the elementary reaction steps of the electrochemical process were investigated through kinetic analysis. The results indicate that the proposed method has a detection range of 10–80 nmol/L and a detection limit (LOD) of 5.52 nmol/L (3 σ /slope). Within the temperature range of 20–36 °C, the detection error significantly decreased to 7.03%. The detection error significantly decreased to 6.21% within the pH range of 6.65–7.28, confirming the high sensitivity and adaptive compensation capability of this method. It has a high recovery rate in real water experiments, providing a high‐precision and highly sensitive new method for detecting heavy metal ions in random water environments.
