RESUMEN

A novel smartphone-assisted fluorescent microfluidic-chip was designed for detecting sweat glucose. The microfluidic chip contained six microchambers, each of which was equipped with a glucose sensing membrane incorporating glucose oxidase (GOD), fluorescent O2 probe PtTFPP and H2O2 probe G1. Based upon O2 consumption and H2O2 generation during glucose catalysis by GOD, the chip produced two fluorescence signals towards glucose under single-wavelength excitation, i.e. green fluorescence in response to H2O2 and red fluorescence to O2. The limit of detection (LOD) based on H2O2 monitoring was 0.005 mM, while the LOD based on O2 monitoring was 0.04 mM. Furthermore, the obtained chip was integrated with a smartphone-based portable platform to record RGB values for point-of-care testing of sweat glucose. Glucose calibration (Y = -3.45 + 1.81∗R + 0.68∗G) at 6-min time point was performed by combining R and G channels signals. The dual-monitoring analysis provided a more accurate and reliable verification of glucose detection. This smartphone-assistant optical microfluidic-chip device holds significant potential for portable self-management of glucose in personalized healthcare and clinical diagnosis.

RESUMEN

The development of electrochemical glucose sensors with high sensitivity, specificity, and stability, enabling real-time continuous monitoring, has posed a significant challenge. However, an opportunity exists to fabricate electrochemical glucose biosensors with optimal performance through innovative device structures and surface modification materials. This paper provides a comprehensive review of recent advances in electrochemical glucose sensors. Novel classes of nanomaterials-including metal nanoparticles, carbon-based nanomaterials, and metal-organic frameworks-with excellent electronic conductivity and high specific surface areas, have increased the availability of reactive sites to improved contact with glucose molecules. Furthermore, in line with the trend in electrochemical glucose sensor development, research progress concerning their utilisation with sweat, tears, saliva, and interstitial fluid is described. To facilitate the commercialisation of these sensors, further enhancements in biocompatibility and stability are required. Finally, the characteristics of the ideal electrochemical glucose sensor are described and the developmental trends in this field are outlines.

RESUMEN

In this study, a new amperometric biosensor was developed for glucose determination. For this purpose, polyaniline-polypyrrole-poly(sodium-4-styrenesulfonate) film was prepared by electropolymerization of aniline and pyrrole with poly(sodium-4-styrenesulfonate) on a platinum plate. The best working conditions of the polyaniline-polypyrrole-poly(sodium-4-styrenesulfonate) film were determined. The glucose oxidase enzyme was immobilized by the entrapment method in polyaniline-polypyrrole-poly(sodium-4-styrenesulfonate) film. Glucose determination was made based on the oxidation of hydrogen peroxide, which is formed as a result of the enzymatic reaction on the surface of the prepared biosensor at +0.40 V. The working range for the glucose determination of the biosensor was determined. The effects of pH and temperature on the response of the glucose biosensor were investigated. The reusability and shelf life of the biosensor were determined. The effects of interference in biological environments on the response of the biosensor were investigated. Glucose determination was made in the biological fluid (blood) with the prepared biosensor. This study has a feature that sheds light on biosensor studies to be developed for the detection of substances in the human body, such as glucose, uric acid, and urea. This article will set an example for future scientific research on the development of a sensor for other biological fluids in the human body, such as the sensor developed for blood samples. In addition, this developed sensor provides an innovation that improves the quality of life of patients by allowing them to constantly monitor their glucose levels and intervene when necessary.

RESUMEN

To enhance personalized diabetes management, there is a critical need for non-invasive wearable electrochemical sensors made from flexible materials to enable continuous monitoring of sweat glucose levels. The main challenge lies in developing glucose sensors with superior electrochemical characteristics and high adaptability. Herein, we present a wearable sensor for non-enzymatic electrochemical glucose analysis. The sensor was synthesized using hydrothermal and one-pot preparation methods, incorporating gold nanoparticles (AuNPs) functionalized onto aminated multi-walled carbon nanotubes (AMWCNTs) as an efficient catalyst, and crosslinked with carboxylated styrene butadiene rubber (XSBR) and PEDOT:PSS. The sensors were then integrated onto screen-printed electrodes (SPEs) to create flexible glucose sensors (XSBR-PEDOT:PSS-AMWCNTs/AuNPs/SPE). Operating under neutral conditions, the sensor exhibits a linear range of 50 µmol/L to 600 µmol/L, with a limit of detection limit of 3.2 µmol/L (S/N = 3), enabling the detection of minute glucose concentrations. The flexible glucose sensor maintains functionality after 500 repetitions of bending at a 180° angle, without significant degradation in performance. Furthermore, the sensor exhibits exceptional stability, repeatability, and resistance to interference. Importantly, we successfully monitored changes in sweat glucose levels by applying screen-printed electrodes to human skin, with results consistent with normal physiological blood glucose fluctuations. This study details the fabrication of a wearable sensor characterized by ease of manufacture, remarkable flexibility, high sensitivity, and adaptability for non-invasive blood glucose monitoring through non-enzymatic electrochemical analysis. Thus, this streamlined fabrication process presents a novel approach for non-invasive, real-time blood glucose level monitoring.

Asunto(s)

Técnicas Biosensibles , Glucosa , Oro , Nanotubos de Carbono , Sudor , Dispositivos Electrónicos Vestibles , Humanos , Sudor/química , Glucosa/análisis , Oro/química , Nanotubos de Carbono/química , Técnicas Biosensibles/métodos , Electrodos , Técnicas Electroquímicas/métodos , Técnicas Electroquímicas/instrumentación , Nanopartículas del Metal/química , Límite de Detección

RESUMEN

Electronic waste (e-waste) and diabetes are global challenges to modern societies. However, solving these two challenges together has been challenging until now. Herein, we propose a laser-induced transfer method to fabricate portable glucose sensors by recycling copper from e-waste. We bring up a laser-induced full-automatic fabrication method for synthesizing continuous heterogeneous CuxO (h-CuxO) nano-skeletons electrode for glucose sensing, offering rapid (< 1 min), clean, air-compatible, and continuous fabrication, applicable to a wide range of Cu-containing substrates. Leveraging this approach, h-CuxO nano-skeletons, with an inner core predominantly composed of Cu2O with lower oxygen content, juxtaposed with an outer layer rich in amorphous CuxO (a-CuxO) with higher oxygen content, are derived from discarded printed circuit boards. When employed in glucose detection, the h-CuxO nano-skeletons undergo a structural evolution process, transitioning into rigid Cu2O@CuO nano-skeletons prompted by electrochemical activation. This transformation yields exceptional glucose-sensing performance (sensitivity: 9.893 mA mM-1 cm-2; detection limit: 0.34 µM), outperforming most previously reported glucose sensors. Density functional theory analysis elucidates that the heterogeneous structure facilitates gluconolactone desorption. This glucose detection device has also been downsized to optimize its scalability and portability for convenient integration into people's everyday lives.

RESUMEN

1D nanomaterials have attracted great attention due to their outstanding anisotropic and linear structures. A facile method is developed to fabricate 1D copper metal-organic framework nanowires (Cu-MOF-NW) through steam-assisted conversion from Cu-MOF precursors. During the steam-assisted conversion, Cu-MOF precursor gradually dissolves in methanol steam, and then recrystallized into Cu-MOF-NW, which shows high aspect ratio of about 600 and identical crystal structure of MOF-74. As-prepared Cu-MOF-NW with multiscale porous structure can effectively remove cationic dyes even in dye mixture. Moreover, Cu-MOF-NW, as an ideal template, is calcined to form Cu nanoparticle-doped carbon nanofiber with maintaining its 1D morphology, which shows excellent electrocatalytic activity for the non-enzymatic sensing of glucose.

RESUMEN

BACKGROUND: With the advent of personalized medical approaches, precise and tailored treatments are expected to become widely accepted for the prevention and treatment of diabetes. Paper-based colorimetric sensors that function in combination with smartphones have been rapidly developed in recent years because it does not require additional equipment and is inexpensive and easy to perform. In this study, we developed a portable, low-cost, and wearable sweat-glucose detection device for in situ detection. RESULTS: The sensor adopted an integrated biomimetic nanoenzyme of glucose oxidase (GOx) encapsulated in copper 1, 4-benzenedicarboxylate (CuBDC) (GOx@CuBDC) through a biomimetic mineralization process. CuBDC exhibited a peroxide-like effect, cascade catalytic effect with the encapsulated GOx, and increased the enzyme stability. GOx@CuBDC and 3,3,5,5-tetramethylbenzidine were combined to form a hybrid membrane that achieved single-step paper-based glucose detection. SIGNIFICANCE AND NOVELTY: This GOx@CuBDC-based colorimetric glucose sensor was used to quantitatively analyze the sweat-glucose concentration with smartphone readings. The sensor exhibited a good linear relationship over the concentration range of 40-900 µM and a limit of detection of 20.7 µM (S/N = 3). Moreover, the sensor performed well in situ monitoring and in evaluating variations based on the consumption of foods with different glycemic indices. Therefore, the fabricated wearable sweat-glucose sensors exhibited optimal practical application performance.

Asunto(s)

Técnicas Biosensibles , Colorimetría , Cobre , Glucosa Oxidasa , Glucosa , Teléfono Inteligente , Sudor , Glucosa Oxidasa/química , Glucosa Oxidasa/metabolismo , Cobre/química , Sudor/química , Humanos , Glucosa/análisis , Dispositivos Electrónicos Vestibles , Límite de Detección , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo

RESUMEN

This study presents a modified screen-printed carbon electrode (SPCE) to determine glucose in a custom-built flow injection system. The biosensor was constructed by immobilizing glucose oxidase on porous platinum nanoparticles decorated on multi-walled carbon nanotubes (GOx@PPtNPs@MWCTNs). The fabrication of the biosensor was completed by coating the GOx@PPtNPs@MWCTNs nanocomposite on an SPCE modified with a nanocomposite of poly(3,4-ethylenedioxythiophene) and Prussian blue (GOx@PPtNPs@MWCTNs/PEDOT@PB/SPCE). The fabricated electrode accurately measured hydrogen peroxide (H2O2), the byproduct of the GOx-catalyzed oxidation of glucose, and was then applied as a glucose biosensor. The glucose response was amperometrically determined from the PB-mediated reduction of H2O2 at an applied potential of -0.10 V in a flow injection system. Under optimal conditions, the developed biosensor produced a linear range from 2.50 µM to 1.250 mM, a limit of detection of 2.50 µM, operational stability over 500 sample injections, and good selectivity. The proposed biosensor determined glucose in human plasma samples, achieving recoveries and results that agreed with the hexokinase-spectrophotometric method (P > 0.05). Combining the proposed biosensor with the custom-built sample feed, a portable potentiostat and a smartphone, enabled on-site glucose monitoring.

Asunto(s)

Técnicas Biosensibles , Compuestos Bicíclicos Heterocíclicos con Puentes , Electrodos , Análisis de Inyección de Flujo , Glucosa Oxidasa , Nanocompuestos , Nanotubos de Carbono , Platino (Metal) , Polímeros , Teléfono Inteligente , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Polímeros/química , Nanocompuestos/química , Glucosa Oxidasa/química , Técnicas Biosensibles/métodos , Nanotubos de Carbono/química , Platino (Metal)/química , Humanos , Glucemia/análisis , Glucosa/análisis , Glucosa/química , Técnicas Electroquímicas/métodos , Peróxido de Hidrógeno/química , Ferrocianuros/química , Nanopartículas del Metal/química , Enzimas Inmovilizadas/química , Carbono/química , Límite de Detección

RESUMEN

Amino acids are not only the building blocks of proteins but also lead to the development of novel nanomaterials with unique properties. Herein, we proposed a simple strategy to produce gold nanoparticles (Au NPs) with peroxidase-like (POD-like) activities by using a series of amino acids as reducing agents, named Au NPs@M (M represents different amino acids). The Au NPs@His was identified as the nanozyme with the most potent catalytic performance, which was used in combination with smartphones to achieve rapid detection of hydrogen peroxide with a detection limit of 0.966 µM. It also enables rapid detection of glucose with a detection limit of 2.904 µM, highlighting the significant contribution of Au NPs@His in expediting the detection of critical biomolecules. This work not only provides a convenient and highly efficient method to identify glucose but also shows the potential of histidine as a reducing agent in constructing Au nanomaterials exerting enzyme-like catalysis.

Asunto(s)

Aminoácidos , Glucosa , Oro , Peróxido de Hidrógeno , Nanopartículas del Metal , Teléfono Inteligente , Oro/química , Nanopartículas del Metal/química , Peróxido de Hidrógeno/análisis , Peróxido de Hidrógeno/química , Aminoácidos/química , Aminoácidos/análisis , Glucosa/análisis , Técnicas Biosensibles , Catálisis , Límite de Detección , Histidina/análisis , Histidina/química

RESUMEN

BACKGROUND: Non-invasive indirect blood glucose monitoring can be realized by detecting low concentrations of glucose (0.05-5 mM) in tears, but sensitive optical indicators are required. The intensity of the phosphorescence of a candidate optical indicator, palladium hematoporphyrin monomethyl ether (Pd-HMME), is increased by oxygen consumption under sealed conditions in the presence of glucose and glucose oxidase. However, the glucose detection limit based on this mechanism is high (800 µM) because the phosphorescence is completely quenched under ambient oxygen conditions and hence a large amount of glucose is required to reduce the oxygen levels such that the phosphorescence signal is detectable. RESULTS: To improve the glucose detection limit of Pd-HMME phosphorescence-based methods, the triplet protector imidazole was introduced, and strong phosphorescence was observed under ambient oxygen conditions. Detectable phosphorescence enhancement occurred at low glucose concentrations (<200 µM). Linear correlation between the phosphorescence intensity and glucose concentration was observed in the range of 30-727 µM (R2 = 99.9 %), and the detection limit was ∼10 µM. The glucose sensor has a fast response time (∼90 s) and excellent selectivity for glucose. SIGNIFICANCE AND NOVELTY: These results indicate the potential of the developed optical indicator for fast, selective, and reliable low-concentration glucose sensing.

Asunto(s)

Límite de Detección , Mediciones Luminiscentes , Mediciones Luminiscentes/métodos , Hematoporfirinas/química , Hematoporfirinas/análisis , Paladio/química , Glucosa/análisis , Glucosa Oxidasa/química , Glucosa Oxidasa/metabolismo , Glucemia/análisis , Imidazoles/química , Técnicas Biosensibles/métodos , Oxígeno/química , Humanos

RESUMEN

Today, diabetes mellitus is one of the most common diseases that affects the population on a worldwide scale. Patients suffering from this disease are required to control their blood-glucose levels several times a day through invasive methods such as piercing their fingers. Our NaGdF4: 5% Er3+, 3% Nd3+ nanoparticles demonstrate a remarkable ability to detect D-glucose levels by analysing alterations in their red-to-green ratio, since this sensitivity arises from the interaction between the nanoparticles and the OH groups present in the D-glucose molecules, resulting in discernible changes in the emission of the green and red bands. These luminescent sensors were implemented and tested on paper substrates, offering a portable, low-cost and enzyme-free solution for D-glucose detection in aqueous solutions with a limit of detection of 22 mg/dL. With this, our study contributes to the development of non-invasive D-glucose sensors, holding promising implications for managing diabetes and improving overall patient well-being with possible future applications in D-glucose sensing through tear fluid.

Asunto(s)

Glucosa , Metales de Tierras Raras , Nanopartículas , Papel , Metales de Tierras Raras/química , Glucosa/análisis , Glucosa/química , Nanopartículas/química , Técnicas Biosensibles/métodos , Humanos , Glucemia/análisis , Límite de Detección

RESUMEN

Nanozymes are nanomaterials with mimetic enzyme properties and the related research has attracted much attention. It is of great value to develop methods to construct nanozymes and to study their application in bioanalysis. Herein, the metal-ligand cross-linking strategy was developed to fabricate superstructure nanozymes. This strategy takes advantage of being easy to operate, adjustable, cheap, and universal. The fabricated superstructure nanozymes possess efficient peroxidase-like catalytic activity. The enzyme reaction kinetic tests demonstrated that for TMB and H2O2, the Km is 0.229 and 1.308 mM, respectively. Furthermore, these superstructure nanozymes are applied to highly efficient and sensitive detection of glucose. The linear range for detecting glucose is 20-2000 µM, and the limit of detection is 17.5 µM. Furthermore, mechanistic research illustrated that this integrated system oxidizes glucose to produce hydrogen peroxide and further catalyzes the production of ·OH and O2·-, which results in a chromogenic reaction of oxidized TMB for the detection of glucose. This work could not only contribute to the development of efficient nanozymes but also inspire research in the highly sensitive detection of other biomarkers.

RESUMEN

Designing portable electrochemical sensors combined with highly efficient glucose oxidation electrodes offers a significant opportunity for convenient glucose detection. In this report, we present the design and preparation of platinum deposited Ni/NiFe2O4/Carbon composite (Pt/Ni/NiFe2O4/C) derived from Ni/Fe metal-organic frameworks (MOFs) followed by Pt deposition. Energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electron microscopy (EM) were utilized to analyze the crystal structure, morphology, and chemical composition of the resulting materials. The glucose sensing capabilities of the optimal Pt/Ni/NiFe2O4/C-3 were assessed using amperometry methods on a smartphone-based portable device. Acting as a nonenzymatic glucose sensor, the Pt/Ni/NiFe2O4/C-3 electrode demonstrated notable sensitivity and a low limit of detection for glucose. The portable sensor exhibits high sensitivities of 131.88 µM mM cm-2 at low glucose concentration (3-500 µM) and 29.52 µA mM cm-2 at high glucose concentration (700-4000 µM), achieving a low detection limit of 1.1 µM (S/N = 3). The sensor also demonstrates enhanced selectivity and stability for detecting glucose. Furthermore, the portable sensor exhibits a clear step-ampere response in the detection of serum samples with satisfactory recovery ranging from 99.30 to 101.32%. This suggests the significant potential of portable glucose sensing applications.

RESUMEN

The synthesis of heterojunction materials is regarded as an efficient way to enhance catalytic activities in various catalytic reactions. However, the existing fabrication approaches often rely on complex multi-step synthesis process. In this work, we fabricate sweater-ball shaped nanostructured MOF/TMS (Ni-MOF/NiS1.03) heterojunction by one-pot, one-step solvothermal method. According to the results of discrete Fourier transform (DFT) calculations and experiments, the formation of Ni-MOF/NiS1.03 heterojunction interfaces improves electron transfer and charge redistribution, and increases the adsorption energy of glucose molecules as well, which is conducive to enhance electrochemical activity of electrode materials. The as-prepared Ni-MOF/NiS1.03 heterojunction exhibit enhanced glucose sensitivity, wide detection range and low detection limit. This study paves the way towards the development of MOF-based heterojunctions for electrochemical applications.

RESUMEN

Developing an accurate, cost-effective, reliable, and stable glucose detection sensor for the food industry poses a significant yet challenging endeavor. Herein, we present a silver nanoparticle-decorated titanium dioxide nanoribbon array on titanium plate (Ag@TiO2/TP) as an efficient electrode for non-enzymatic glucose detection in alkaline environments. Electrochemical evaluations of the Ag@TiO2/TP electrode reveal a broad linear response range (0.001 mM - 4 mM), high sensitivity (19,106 and 4264 µA mM-1 cm-2), rapid response time (6 s), and a notably low detection limit (0.18 µM, S/N = 3). Moreover, its efficacy in measuring glucose in beverage samples shows its practical applicability. The impressive performance and structural benefits of the Ag@TiO2/TP electrode highlight its potential in advancing electrochemical sensors for small molecule detection.

Asunto(s)

Técnicas Biosensibles , Nanopartículas del Metal , Nanotubos de Carbono , Nanopartículas del Metal/química , Técnicas Electroquímicas , Plata , Glucosa/química , Electrodos

RESUMEN

Managing diabetes is a chronic challenge today, requiring monitoring and timely insulin injections to maintain stable blood glucose levels. Traditional clinical testing relies on fingertip or venous blood collection, which has facilitated the emergence of continuous glucose monitoring (CGM) technology to address data limitations. Continuous glucose monitoring technology is recognized for tracking long-term blood glucose fluctuations, and its development, particularly in wearable devices, has given rise to compact and portable continuous glucose monitoring devices, which facilitates the measurement of blood glucose and adjustment of medication. This review introduces the development of wearable CGM-based technologies, including noninvasive methods using body fluids and invasive methods using implantable electrodes. The advantages and disadvantages of these approaches are discussed as well as the use of microneedle arrays in minimally invasive CGM. Microneedle arrays allow for painless transdermal puncture and are expected to facilitate the development of wearable CGM devices. Finally, we discuss the challenges and opportunities and look forward to the biomedical applications and future directions of wearable CGM-based technologies in biological research.

Asunto(s)

Diabetes Mellitus , Dispositivos Electrónicos Vestibles , Humanos , Glucosa , Glucemia , Automonitorización de la Glucosa Sanguínea , Diabetes Mellitus/diagnóstico

RESUMEN

This work demonstrates the use of jute stick extract as a reducing and stabilizing agent for the synthesis of spherical gold nanoparticles (AuNPs). In UV-Vis spectroscopy, peak at 550 nm was used to confirm the formation of AuNPs. The spherical surface morphology of AuNPs was determined through SEM and TEM analysis. While XRD investigation revealed the crystallinity of the prepared AuNPs. To ensure the biocompatibility of synthesized AuNPs, a bacterial investigation was conducted with negative results towards bacterial strain. The, modified FTO with AuNPs were able to detect glucose in CV analysis and the constructed sensor displayed a wide linear range of 50 µM to 40 mM with a detection limit of 20 µM. Scan rate analysis was performed to determine the charge transfer coefficient (0.42) and Tafel slope (102 mV/decade). Furthermore, the interfacial surface mechanism is illustrated to understand the interaction of glucose with the electrode surface in an alkaline medium and the product formation through the dehydrogenation and hydrolysis process. The prepared sensor also showed good stability, reproducibility, and anti-interference capabilities. In the case of real sample analysis, we used a blood serum sample. A low RSD value (<10 %) suggests the practical use of AuNPs/FTO in real-life applications.

Asunto(s)

Técnicas Biosensibles , Técnicas Electroquímicas , Electrodos , Flúor , Oro , Nanopartículas del Metal , Compuestos de Estaño , Oro/química , Nanopartículas del Metal/química , Flúor/química , Compuestos de Estaño/química , Materiales Biocompatibles/química , Materiales Biocompatibles/síntesis química , Glucosa/análisis , Propiedades de Superficie , Humanos , Glucemia/análisis , Tamaño de la Partícula

RESUMEN

Accurate cellular-recognition based disease therapy is of significance for precision medicine. However, except of specific antibody-coupling strategy, very few probes have been reported to efficiently discriminate normal cells and lesion cells through cellular microenvironment. Herein, we proposed a glucose selectively-lightened upconversion nanoprobe to recognize cancer cells from a pile of normal cells based on Warburg effect, that indicated a heightened demand for glucose intake for cancer cells. The nanoprobes were constructed by mesoporous silica-coated upconversion nanoparticles (UCNP@mSiO2) with the crucial incorporation of a glucose-responsive modality, benzoboric acid (BA)-modified fluorescein molecules (FITC-BA). In cancer cells, the presence of elevated glucose concentrations triggered the transformation of FITC-BA to FITC-Glucose to recover nanoprobes' luminescence, however, the nanoprobes exhibited a shielded luminescent effect in healthy cells. To validate the hypothesis of accurate cellular-discrimination, a photodynamic therapy modality, riboflavin, with a specific ratio were also loaded into above UCNP@mSiO2 nanoprobes for effective production of reactive oxygen species to kill cells. It was found that 97.8% of cancer cells were cleaned up, but normal cells retained a nearly 100% viability after 10 min laser illumination. By leveraging the metabolic disparity from Warburg effect, the nanoprobes offer a highly accurate cellular discrimination, and significantly mitigate "off-target" damage commonly associated with conventional therapies.

Asunto(s)

Nanopartículas , Fluoresceína-5-Isotiocianato , Luz , Línea Celular Tumoral , Luminiscencia

RESUMEN

BACKGROUND: Nanocellulose is not only a biocompatible and environmentally friendly material but also has excellent mechanical properties, biodegradability, and a large number of hydroxyl groups that have a strong affinity for water. These characteristics have attracted significant attention from researchers in the field of glucose sensing. OBJECTIVE: This review provides a brief overview of the current research status of traditional materials used in glucose sensors. The sensing performance, chemical stability, and environ-mental properties of nanocellulose-based glucose sensors are compared and summarized based on the three sensing methods: electrochemical sensing, colorimetric sensing, and fluo-rescence sensing. The article focuses on recent strategies for glucose sensing using nanocel-lulose as a matrix. The development prospects of nanocellulose-based glucose sensors are also discussed. CONCLUSION: Nanocellulose has outstanding structural characteristics that contribute signifi-cantly to the sensing performance of glucose sensors in different detection modes. However, the preparation process for high-quality nanocellulose is complicated and has a low yield. Furthermore, the sensitivity and selectivity of nanocellulose-based glucose sensors require further improvement.

RESUMEN

Nanozyme technology has gained significant regard and been successfully implemented in various applications including chemical sensing, bio-medicine, and environmental monitoring. Fe-CDs were synthesized and characterized well in this study. As compared to HRP (3.7 mM), the Fe-CDs exhibited a higher affinity towards H2O2 (0.2 mM) using the steady-state kinetic assay and stronger catalytic capability by changing the color of TMB to the blue color of the oxidized state, oxTMB. Additionally, an efficient peroxidase mimic, Fe-CDs/GOx, based on the hybrid cascade system to produce in situ H2O2 for the visual detection of glucose (color change: colorless to blue, and then to green), has been developed in detail, with limits of detection (LODs) for H2O2 and glucose of 0.33 µM and 1.17 µM, respectively. The changes further demonstrate a linear relationship between absorbance and H2O2 concentration, ranging from 10 to 60 µM, and for glucose (1 to 60 µM). To assess the accuracy and detection capability of the Fe-CDs/GOx system, we evaluated a real human serum sample obtained from adult males in a local hospital. In conclusion, Fe-CDs serving as a peroxidase mimic have the potential for various applications in the fields of biomedicine and nanozymes.