Standard Addition Research Articles

N-acetyl-tryptophan in Acute Kidney Injury after Cardiac Surgery.

Cardiac surgery-associated acute kidney injury is a common serious complication after cardiac surgery. Currently, there are no specific pharmacological therapies. Our understanding of its pathophysiology remains preliminary. A total of 2504 patients with and without acute kidney injury (AKI) following cardiac surgery were enrolled. High-performance liquid chromatography coupled with mass spectrometry was used for untargeted analysis of metabolites in plasma, identifying significant differential metabolites. Subsequently, a tandem liquid chromatography-mass spectrometry-based approach using isotope-labeled standard addition was performed for targeted analysis of the metabolic marker N-acetyl-tryptophan. The function of N-acetyl-tryptophan was determined using different kidney injury mouse models and epithelial cellular models. Transcriptome sequencing, surface plasmon resonance and protein mutation were employed to explore the mechanism of N-acetyl-tryptophan on the kidney. We identified a total of 32 differential metabolites related to AKI occurrence based on a cohort of 1042 patients. Among them, N-acetyl-tryptophan was elevated in plasma of patients with cardiac surgery-associated acute kidney injury compared with those who do not develop AKI after cardiac surgery. The higher level of N-acetyl-tryptophan in plasma was confirmed by accurate targeted quantification. N-acetyl-tryptophan exhibited kidney protective effects in ischemia/reperfusion-, cisplatin-, and unilateral ureteral obstruction-induced kidney injury mouse models. Mechanistically, N-acetyl-tryptophan exerted kidney protective effects by interacting with KEAP1 at 483 and 508 sites, resulting in Nrf2 nuclear translocation and the transcription of proteasome genes. N-acetyl-tryptophan plays a key role in kidney protection.

Compensation for Matrix Effects in High-Dimensional Spectral Data Using Standard Addition

Compensation for Matrix Effects in High-Dimensional Spectral Data Using Standard Addition

The clean analysis process of Mn2+ for industries: a comparative study on direct determination of high-concentration Mn2+ in solution using spectrophotometry

Mn2+ is an essential cation extensively utilized in various industrial processes, including electrolytic manganese production, manganese dioxide manufacturing, and zinc processing. It also poses significant environmental challenges as a primary pollutant in Mn-containing wastewater and hazardous materials. Effective monitoring and control of Mn2+ in these processes are vital for improving resource conversion efficiency and minimizing pollutant production. However, the direct determination of high concentrations of Mn2+ remains challenging due to rapid reactions, which impede improvements in cleaner industrial production. Traditional detection method like potassium periodate spectrophotometry (PPS) method is limited to low concentrations and involve complex processes that contribute to secondary pollution. In this study, we evaluated the performance of four alternative methods—External Standard Calibration (EC), Area Under the Curve (AUC), Standard Addition (SA), and Multi-Energy Calibration (MEC)—for determining high-concentration Mn²⁺. The study found that the weak absorption characteristic of aqueous Mn²⁺ due to spin-forbidden transitions is advantageous for direct determination at high concentrations in its original valence state. By optimizing the optical path and wavelength, concentrations up to 50 g/L were detected, surpassing the PPS upper limit by 5000 times. Among the methods, EC demonstrated superior accuracy and precision, with a performance rate of 98.07% and a relative standard deviation of less than 1%. The EC method’s minimal time consumption and cost-effectiveness make it suitable for automation and integration into industrial systems for continuous, real-time monitoring. This research offers valuable insights into high-concentration Mn2+ determination using spectrophotometry, highlighting the EC method’s potential for real-time monitoring and its adaptability for large-scale industrial operations. The findings provide a substantial reference for the direct detection of other industrial components, promoting more efficient and environmentally friendly industrial practice.

Electrochemical Method for the Assay of Organic Peroxides Directly in Acetonitrile.

Lipid peroxidation is a major process that determines the quality of various oil samples during their use and storage, in which the primary products are hydroperoxides (HP'S). HP'S are very stable compounds at ambient conditions and are harmful to human health. Therefore, the evaluation of the degree of oil oxidation is an excellent tool for ensuring food safety. The peroxide value (PV) is the main parameter used for quality control in oils. Herein, we propose an alternative electrochemical method to the classical iodometric titration method most widely used for determining the PV. Our approach is based on the electrochemical quantification of hydroperoxides/peroxides in an organic solvent medium (acetonitrile and organic ammonium salt) using a composite electrocatalyst-glassy carbon electrode modified with 2D-nanomaterial graphitic carbon nitride doped with Co3O4. Calibration was made by the method of standard addition using benzoyl peroxide (BPO) as a model peroxide compound, dissolved in chloroform and added to fresh Rivana-branded anti-cellulite oil, used as a model oil sample. Calibration plots showed a linear response and the very good reproducibility of the analytical result (R2 ˃ 0.99). Further, in terms of accuracy, the method showed good results, since the BPO quantitative analysis was close to the theoretical response. In addition, the accuracy of the electrochemical method was compared with that of the standard iodometric titration method for determining the PV of vegetable fats (according to a standard method). Finally, using the electrochemical method, the concentration of peroxides was determined in a real sample-an anti-cellulite oil of the trademark Rivana with an expired shelf life.

A voltammetric method for determining N-nitrosodimethylamine in losartan and olmesartan drugs.

Recently, the National Health Surveillance Agency (ANVISA) of Brazil recalled several lots of sartan drugs due to the presence of N-nitrosodimethylamine (NDMA). NDMA is a highly potent carcinogenic contaminant that harms human health; therefore, the presence of NDMA in sartan drugs must be checked through appropriate analytical methods. This work successfully developed a new analytical method for determining NDMA without chemical pretreatment of losartan and olmesartan drug samples. The method uses the square-wave anodic stripping voltammetric (SWASV) technique, a boron-doped diamond electrode (BDDE), and a standard additions procedure (SAP). The proposed SWASV-BDDE-SAP method provided a linear response in the concentration range between 250 and 2500 nmol L-1 (R2 = 0.995, n = 10), a limit of detection (LOD) of 67.6 nmol L-1, satisfactory accuracy (94.3% - 104.7%) without bias, and with good reproducibility (standard deviation = 5.6 %). The results obtained in determining NDMA in losartan and olmesartan drugs using the proposed and reference methods (HPLC-DAD) did not show a statistically significant difference, applying the paired t-test at a confidence level of 95%. In addition, the proposed method uses instrumentation with low acquisition, operation, and maintenance costs and enables rapid determination of NDMA in sartan drugs with great sensitivity, reproducibility, and stability. As the proposed SWASV-BDDE-SAP method does not use chemical pretreatment of samples, such as derivatization and/or extraction with reagents and/or organic solvents, it can be considered a promising eco-friendly alternative for determining NDMA in routine analysis, thus contributing to green analytical chemistry.

Evaluation of four different standard addition approaches with respect to trueness and precision.

This work provides a statistical analysis of four different approaches suggested in the literature for the estimation of an unknown concentration based on data collected using the standard addition method. These approaches are the conventional extrapolation approach, the interpolation approach, inverse regression, and the normalization approach. These methods are compared under the assumption that the measurement errors are normally distributed and homoscedastic. Comparison is done with respect to the two most important characteristics of every estimator, namely trueness (bias) and precision (variability). In addition, the authors supply, if not already available, mathematical formulas to approximate both quantities. Also, a real-world data set is used to illustrate the performance of all four methods. It turns out, that, given that all assumptions underlying the use of the standard addition method apply, the common extrapolation method is still the most recommendable method with respect to bias and variability. Nonetheless, if additional concerns come into play, other methods like, for example, the normalization approach in the case of increased problems with outliers might also be of interest for the practitioner.

A Sensitive and Selective Electrochemical Aptasensor for Carbendazim Detection.

Carbendazim (CBZ) is used to prevent fungal infections in agricultural crops. Given its high persistence and potential for long-term health effects, it is crucial to quickly identify pesticide residues in food and the environment in order to mitigate excessive exposure. Aptamer-based sensors offer a promising solution for pesticide detection due to their exceptional selectivity, design versatility, ease of use, and affordability. Herein, we report the development of an electrochemical aptasensor for CBZ detection. The sensor was fabricated through a one-step electrodeposition of platinum nanoparticles (Pt NPs) and reduced graphene oxide (rGO) on a glassy carbon electrode (GCE). Then, a CBZ-specific aptamer was attached via Pt-sulfur bonds. Upon combining CBZ with the aptamer on the electrode surface, the redox reaction of the electrochemical probe K4[Fe(CN)6] is hindered, resulting in a current drop. Under optimized conditions (pH of 7.5 and 25 min of incubation time), the proposed aptasensor showed a linear current reduction to CBZ concentrations between 0.5 and 15 nM. The limit of detection (LOD) for this proposed aptasensor is 0.41 nM. Along with its repeatable character, the aptasensor demonstrated better selectivity for CBZ compared to other potential compounds. The recovery rates for detecting CBZ in skim milk and tap water using the standard addition method were 98% and 96%, respectively. The proposed aptasensor demonstrated simplicity, sensitivity, and selectivity for detecting CBZ with satisfactory repeatability. It establishes a strong foundation for environmental monitoring of CBZ.

Highly Sensitive Non-Enzymatic Electrochemical Sensor to Detect an Important Neurotransmitter Using Cobalt-Based Metal-Organic Framework/Graphene Oxide Composite

Glutamate (Glu) is a principal neurotransmitter owing to its significant function in physiological and pathological processes. Deviations in Glu levels have been associated with the onset of various neurological disorders, implicating it as a potential biomarker for conditions like epilepsy, stroke, Alzheimer’s disease, and amyotrophic lateral sclerosis. Accurate detection of Glu is essential for the prevention, diagnosis, and treatment of such diseases. Herein, a highly sensitive non-enzymatic sensor is introduced to detect Glu. The electrochemical performance of Glu was studied by modifying the glassy carbon electrode using a cobalt-based metal-organic framework/graphene oxide composite (CoMG/GCE). Differential pulse voltammetry exhibited a linear response from 20.0 to 1.00 × 103 μM at an alkali solution with a detection limit of 3.10 μM. DPV was utilized to determine Glu in human blood serum samples using the standard addition method. This sensor showed the lowest interference with popular interference species, indicating its ability for healthcare applications.

Two-Phase Extraction for Comprehensive Analysis of the Plant Metabolome by NMR.

Metabolomics is the area of research, which strives to obtain complete metabolic fingerprints, to detect differences between them and to provide hypothesis to explain those differences (Schripsema J, Dagnino D, Handbook of chemical and biological plant analytical methods. Wiley, New York, 2015). However, obtaining complete metabolic fingerprints is not an easy task. Metabolite extraction is a key step during this process, and much research has been devoted to finding the best solvent mixture to extract as much metabolites as possible.Here a procedure is described for analysis of both polar and apolar metabolites using a two-phase extraction system. D2O and CDCl3 are the solvents of choice, and their major advantage is that, for the identification of the compounds, standard databases can be used because D2O and CDCl3 are the solvents most commonly used for pure compound NMR spectra. The procedure enables the absolute quantification of components due to the addition of suitable internal standards. The extracts are also suitable for further analysis with other systems like LC-MS or GC-MS.

A stable method for ionic rare earth element extraction and quantitative analysis of total quantity and composition of batch samples.

The development of a stable, high-precision and batch ion-adsorption rare earth element detection method is highly anticipated in the delineation and evaluation of the mining value of rare earth element mines. In this study, a novel mixed extractant of ammonium sulfate + ammonium citrate + aceto-sodium acetate buffer was used to significantly improve the extraction efficiency of rare earth elements. Following a series of parameter optimizations, an off-line internal standard addition method and the collision mode of the inductively coupled plasma-mass spectrometer were used to improve the detection efficiency for batch samples, effectively eliminating oxide interference between the rare earth elements and improving the detection accuracy. The detection limit for ion-adsorption rare earth elements was 3.4 μg g-1 and the detection range was 12-8000 μg g-1. More importantly, the spiked and recovery experiments carried out in multiple laboratories with internal quality control samples show that the relative deviation was -5.61 to 3.79%, which indicates that the method has sufficient stability. Establishment of this method will help to improve the comprehensive utilization efficiency of rare earth resources and provide important support for rare earth element mining.

CCQM-K158 elements and inorganic arsenic in rice flour

Main textKRISS and NMIJ jointly coordinated the CCQM-K158 comparison on elements and inorganic As in polished rice flour. The study comprised two parts, Part A and Part B. Successful participation in formal international comparisons is essential for documenting calibration and measurement capability claims (CMCs) by national metrology institutes (NMIs) and designated institutes (DIs). CCQM-K158 specifically supports CMCs within the food category, corresponding to the sample matrix labeled "High organic content" in the new CC table for broad claims. Simultaneously, the CCQM-P200 comparison ran in parallel with the key comparison CCQM-K158.In Part A, sixteen NMIs/DIs participated. Participants were requested to measure the mass fractions of Cu, Hg, K, Na, Pb, and Sb in rice flour, expressed in mg·kg-1, on a dry mass basis. Most NMIs/DIs adopted microwave-assisted acid digestion in a closed vessel for sample pretreatment, except for NIS, which used open vessel acid digestion with heating. Majority of the participants used isotope dilution (ID) ICP-MS, except for K and Na. ICP-MS or ICP-OES with standard addition calibration and k0 INAA were also applied specially for elements of which ID is impossible or difficult to access. ICP-MS, ICP-OES, AAS methods were also used with external calibration.In Part B, fifteen NMIs/DIs participated. Participants were requested to evaluate the mass fractions, expressed in mg·kg-1, of total arsenic and inorganic arsenic (the sum of As (III) and As (V)) in polished rice flour. For total As, thirteen NMIs/DIs reported their analytical results, where all the NMIs/DIs, except for JSI, adopted ICP-MS with a microwave acid digestion. JSI adopted k0-INAA after pelletizing the sample. For inorganic As, seven NMIs/DIs reported their analytical results, where all the NMIs/DIs adopted liquid chromatography-ICP-MS with a thermostatically controlled extraction using diluted acids.The results of all the participating NMIs/DIs were evaluated against the key comparison reference value (KCRV). The KCRV and associated uncertainty were estimated from reported results, excluding outliers, using NIST decision tree (NDT) as an estimator of the KCRVs.Successful participation in CCQM-K158 Part A demonstrates measurement capabilities for determining mass fractions of alkali and alkaline earth (K, Na), transition (Cu, Hg, Pb), and metalloid/semi-metal (Sb) elements in mass fraction range above 0.05 mg kg-1, in high organic content matrices such as grains, beans, and related samples. Similarly, successful participation in CCQM-K158 Part B demonstrates measurement capabilities to determine mass fractions of total arsenic and water-soluble arsenic species such as inorganic arsenic (the sum of As (III) and As (V)), mono-, di-, tri-, and tetra-methyl arsenic compounds (MAA, DMAA, TMAO, TeMA), arsenocholine (AsC), and arsenobetaine (AsB), in mass fraction range above 0.05 mg·kg-1 in grains, beans, and related samples.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Alternative method using Multiple-Injection Capillary Zone Electrophoresis with direct UV detection and single-point standard addition for determination of sorbate and benzoate in ready-to-drink tea

Alternative method using Multiple-Injection Capillary Zone Electrophoresis with direct UV detection and single-point standard addition for determination of sorbate and benzoate in ready-to-drink tea

Study on Differential Pulse Anodic Stripping Voltammetry Method for Simultaneous Determination of Trace amount of Zn, Cd, Pb, Cu in some Cough Syrups in Vietnam

The optimal measurement parameters of differential pulse anodic stripping voltammetry method (DP-ASV) to simultaneously determine the trace amount of the four elements Zn, Cd, Pb, Cu have been studied, including the sweep rate, pulse amplitude, drop size of mercury, initial purge, equilibration time. The analytical procedure was applied to determine Zn, Cd, Pb, Cu in 12 cough syrup samples in Viet Nam, including 6 functional food samples and 6 medicinal samples. The quantitative echnique used was standard addition and the applicability of quantitative elements in self - made samples was studied. Cough syrup analysis samples were digested using the wet ashing method in microwave oven. Research results show that there are no regular differences in elements content between medicinal cough syrup samples and functional food samples, except for functional food samples TP08 which has Pb content and the syrup medicine sample TH03 which has Cu content many times higher than other types. However, the content of the studied elements is within the allowable limits according to curent regulations (QCVN 8-2:2011/BYT; 46/2007/QĐ-BYT, WHO). The method has low detection limits and limit of quantification with ppb level, the relative standard deviations (% RSD) of repeated measurements are less than 3%, and recovery reflects the accuracy of the analytical method for elements ranging from 61.0 % to 87.5 %, which meets AOAC requirements for trace.

Design and Characterization of Novel Naphthalimide Fluorescent Probe for H2S Detection in Human Serum.

In this work, a novel fluorescent probe (compound 2) based on the Intramolecular charge transfer (ICT) mechanism was designed and successfully applied to determine H2S in human serum. Fluorophore 1,8-naphthalimide was chosen, while the azide group was the recognition group for H2S determination. By introducing p-toluidine moiety on the imide part of the molecule, a donor-acceptor (D-A) conjugated system was formed. Prepared compound 2 was characterized using 1H, 13C NMR spectroscopy, and elemental analysis. Fluorescence spectra measurements were carried out, and several influences on fluorescence intensity were investigated, including pH, time dependence, selective response, and influence of H2S concentration. Conducted experiments, including the calculated detection limit of the prepared fluorescent probe, which was found to be 0.085 µmol·L- 1, showing that compound 2 could be applied for H2S detection in human serum and could detect low micromolar concentrations of H2S. Finally, compound 2 was successfully applied to detect H2S in a human serum sample, whereby the concentration of H2S was 17.2 µmol·L- 1. The accuracy of the H2S determination was confirmed with the standard addition method.

Ultrafast Microwave-Synthesized 2D/1D MnO2/Carbon Nanotube Hybrid for Bilirubin Detection in Simulated Blood Serum.

Hybridization of carbon nanotubes (CNTs) and manganese dioxide (MnO2) integrates the biocompatibility and outstanding electrocatalytic activity of MnO2 with the exceptional conductivity of CNTs, thus providing a superior synergistic sensing platform for the detection of biomolecules. However, the existing methods for synthesizing MnO2/CNT hybrids are complex and inefficient, resulting in low yields and limited surface functionalities. Hence, in this study, we present a low-cost and ultrafast solid-phase synthesis of the MnO2/CNT hybrid using a facile microwave technique to detect a crucial biomolecule bilirubin. The successful synthesis of the MnO2/CNT hybrid is confirmed through characteristic Raman and X-ray diffraction peaks, while morphology is analyzed by imaging techniques such as FESEM and HRTEM. The MnO2/CNT/nickel foam (NF) sensor is thereafter used for the electrochemical detection of bilirubin. The sensor demonstrates a wide linear detection range from 10 nM to 1 mM, with a sensitivity of 6.87 mA nM-1 cm-2 toward bilirubin, as determined through the differential pulse voltammetry technique. The lower limit of detection is noted at 3.3 nM (=3.3 S/m). Furthermore, the as-fabricated sensor showcases high selectivity against the interfering species. Real-time analysis conducted in simulated blood serum using the standard addition method reveals an outstanding recovery percentage of approximately 98%. The conductive MnO2/CNT hybrid interacts robustly with bilirubin, aided by the porous NF substrate for stability, catalytic activity, and rapid electron transfer, enabling sensitive bilirubin detection. The work provides an ultrafast, low-cost, and high-yield solid-phase microwave synthesis of MnO2/CNT hybrid material and broadens its application in the detection of biological specimens for clinical diagnosis and biomedical research.

Development and optimisation of the biosensor for aspartate aminotransferase blood level determination.

This work presents the development and optimisation of an amperometric biosensor for determining aspartate aminotransferase (AST) activity in blood serum, using glutamate oxidase and platinum disc electrodes. AST is a key biomarker for diagnosing cardiovascular and liver diseases. The biosensor's bioselective membrane composition and formation protocol and the working solution (aspartate 8mM, α-ketoglutarate 2mM, pyridoxal-5-phosphate 100µM) were optimised. The sensor demonstrated high selectivity, stability (70% retention over 2months at - 18°C), and sensitivity (2.37 nA min⁻1 per 10 U L⁻1), with a dynamic range of 0-500 U L⁻1 and a limit of detection of 1 U L⁻1. Comparative analysis showed the calibration curve method outperforms the standard addition method for AST measurement in serum samples. Additionally, a reference spectrophotometric technique was adapted for AST level determination, showing a strong correlation (r = 0.989) with the biosensor results. This research offers a fast, affordable, and accurate tool for early check-ups of liver and heart conditions. The biosensor's flexibility and ease of use make it suitable for further development into point-of-care testing and personalised healthcare techniques.

Selection of internal standards for the determination of rare earth elements by atomic emission spectrometry with microwave plasma

The method of atomic emission spectrometry with excitation spectra in microwave plasma was used to determine the composition of lanthanum sulfide crystals and europium-doped gadolinium oxide, as well as elements in the melt (tin, boron, and lithium). Calibration curves for rare earth elements are nonlinear and do not provide the required accuracy of analysis. To reduce errors and linearize the calibration curves, the internal standard method was used. Molecular ions N2, N2+ and OH did not correct for changes in plasma conditions and inter-element effects. Internal standard elements were selected based on the proximity of the first ionization potential to the analytes, considering Ba, Al, Ga, and In. The use of these elements as internal standards allowed the linearization of calibration curves, achieving an analytical accuracy of 95−105%. The found total mass of the elements was 97−103% of the sample mass, with accuracy confirmed by the method of standard additions.

Evaluation of Automatic Analysis Software for 1H NMR Spectra Quantification. Impact of Signal Broadening and EDTA Addition.

NMR is a well-established analytical technique that enables the identification and quantification of several compounds in complex mixtures. The implementation of automated analysis software enhances this process by comparing sample spectra with a library of standard reference spectra. One of the key parameters in libraries is the signal line width; however, this may result in a concentration bias for compounds with broad signals, particularly those that are complexing. This study aims to evaluate the quantification of seven compounds commonly present in wine with complexing activity. Four automatic programs and manual deconvolution were used to quantify mixtures of these compounds at known concentrations, both in the presence of cations and with the addition of ethylenediamine-tetraacetate (EDTA) as a chelating agent. Additionally, malate was quantified in a wine sample using the standard addition method, both with and without EDTA. The findings illustrate that three of the programs, which employ the signal width value, underestimate compound concentrations in the presence of cations due to signal broadening. This error was mitigated by the EDTA addition. In contrast, the remaining software, which did not utilize signal line width, obtained similar concentrations in both cases. Future investigations involving the automatic analysis of compounds with complexing activity should take care of sample preparation and/or algorithm selection. Furthermore, future software development should consider allowing flexible adjustments of signal line width in their workflow.

Atomic absorption and inductively coupled plasma atomic emission determination of iron and manganese in medicinal salt mixtures

Complete extraction of analytes from samples and the homogeneity of analyzed solutions were achieved using ultrasonic treatment (20 minutes). The sensitivity, precision, and accuracy of atomic absorption determination of analytes were improved by using Triton X-100 (4%) and calibration solutions based on iron and manganese acetylacetonates. It was demonstrated that sensitivity increased by 1.7 times for manganese and 1.5 times for iron. The iron and manganese content in medicinal salt mixtures was determined using both atomic absorption and inductively coupled plasma atomic emission methods. The results obtained by these two independent methods were compared, showing that the dispersions are homogeneous and the variation in results is minor, attributed to random error. The accuracy of the atomic absorption results was verified using the standard addition method and by varying the sample weight, confirming that systematic error is negligible. The detection limits established by the atomic absorption method were Cmin=0.009 g/mL for iron (Cmin, lit=0.015 g/mL) and Cmin=0.003 g/mL for manganese (Cmin, lit=0.004 g/mL).

Ultrasensitive electrochemical detection of miDNA-21 in human serum based on synergistic signal amplification by conducting polymers and bimetallic nanoparticles

MicroRNA-21 (miRNA-21) is a class of small non-coding RNAs that play a crucial role in the regulation of post-transcriptional gene expression. By leveraging the principle of base complementary pairing, the detection of miRNA-21 can be achieved through its analogue, MicroDNA-21 (miDNA-21), which possesses an identical sequence. Utilizing screen-printed carbon electrodes (SPCE), a conducting polymer (polypyrrole, Ppy), and metal nanocomposites (gold-platinum nanoparticles, Au@Pt NPs) were sequentially electrodeposited to create an electrochemical biosensor for the detection of miDNA-21. This biosensor employed ferrocyanide/ferricyanide (Fe(CN)63−/4−) as the electrochemical signaling probe, and its structure was elucidated via field emission scanning electron microscopy (FESEM) and Energy Dispersive Spectrometer (EDS). Quantitative detection was facilitated through differential pulse voltammetry (DPV), yielding a concentration range and linear fitting equation of 10.00–7.00 × 10.00−14 mol/L: ΔI = 0.5143 lgc + 9.191, R2 = 0.9986. The limit of detection (LOD) was determined to be 2.90 × 10−15 mol/L, with a sensitivity of 9.42 μA/μmol/L·cm2. Subsequent performance assessments confirmed the sensor’s excellent selectivity, reproducibility, and stability. Evaluation using the standard addition method, with normal human serum as the matrix, yielded recoveries ranging from 98.97 % to 102.70 %, and relative standard deviation (RSD) values below 1.00 %. These results demonstrate the method’s viability for practical application in detecting miRNA in human serum.