Detection Of H2O2 Research Articles

Voltammetric determination of hydrogen peroxide at decorated palladium nanoparticles/poly 1,5-diaminonaphthalene modified carbon-paste electrode.

In this work, palladium nanoparticles (PdNPs)/p1,5-DAN/ carbon paste electrode (CPE) and p1,5-DAN/CPE sensors have been developed for determination of hydrogen peroxide. Both sensors showed a highly sensitive and selective electrochemical behaviour, which were derived from a large specific area of poly 1,5 DAN and super excellent electroconductibility of PdNPs. PdNPs/p1,5-DAN/CPE exhibited excellent performance over p1,5-DAN/CPE. Thus, it was used for detecting hydrogen peroxide (H2O2) with linear ranges of 0.1 to 250 µM and 0.2 to 300 µM as well as detection limits (S/N = 3) of 1.0 and 5.0 nM for square wave voltammetry (SWV) and cyclic voltammetry (C.V) techniques, respectively. The modified CPE has good reproducibility, adequate catalytic activity, simple synthesis and stability of peak response during H2O2 oxidation on long run that exceeds many probes. Both reproducibility and stability for H2O2 detection are attributable to the PdNPs immobilized on the surface of p1,5-DAN/CPE. The modified CPE was used for determining H2O2 in real specimens with good stability, sensitivity, and reproducibility.

Improvement of Hydrogen Peroxide and Glucose Detection in Serum using Persistent Luminescent Nanoparticles: Impact of Synthesis Parameters and Particle Size

AbstractPersistent Luminescent Nanoparticles (PLNPs) emit prolonged light after excitation, allowing getting images with high signal‐to‐noise ratio, making them particularly beneficial for in vitro biodetection. In this study, we report the preparation of a library of gallium and zinc‐based Persistent Luminescent Nanoparticles doped with chromium (ZnGa2O4:Cr3+) through two distinct syntheses conducted at 120 °C for 12 hours or 24 hours, followed by a calcination at 500 °C or 750 °C. Using centrifugation, and starting from polydisperse samples, we demonstrated the ability to achieve different sizes in a monodisperse manner. Furthermore, our research revealed that ZnGa2O4:Cr3+ (ZGO) nanoparticles react differently with hydrogen peroxide (H2O2) based on their size, synthesis duration, and calcination temperature. We observed the most significant amplification of persistent luminescence for ZGO particles prepared at 120 °C for 12 hours and calcinated at 500 °C, with a size of approximately 100 nm, in the presence of 100 mM H2O2 (later named ZGO‐2). This study enabled the detection of H2O2 in serum without autofluorescence using the developed PLNPs, with a detection limit of up to 2.1 μM and a recovery rate of around 99 %. Additionally, we designed a glucose test for based on the responsiveness of ZGO PLNPs to H2O2. Using glucose oxidase, the glucose detection limit in serum was established around 0.13 μM, with a detection range between 0–5 μM. These findings could open new avenues to further control the size, synthesis, calcination temperature, and persistent luminescence of PLNPs, thus enhancing their utility in the development of new in vitro biosensors.

Green production of functionalized few-layer borophene decorated with cerium-doped iron oxide nanoparticles for repeatable hydrogen peroxide detection

Functionalized few-layer borophene (FFB) was prepared using gallnut extract and coffee waste extract as natural exfoliating and stabilizing agents in an environmentally friendly ultrasonic and high shear exfoliation. Here, a facile precipitation method was employed to grow iron oxide nanoparticles doped with cerium (Ce-FeONPs) onto the surface of FFB. This intriguing combination of materials yielded Ce-FeONPs nanoparticles that exhibited exceptional peroxidase-like activity, efficiently catalyzing the conversion of 3,3′,5,5′-tetramethylbenzidine (TMB) to a blue oxidized TMB (oxTMB) in the presence of hydrogen peroxide (H2O2). Additionally, the introduction of FFB contributes a reducibility effect to the catalytic oxidation of TMB, facilitating the restoration of the oxTMB to TMB. Thus, FFB-Ce-FeONPs showcase intriguing properties encompassing both oxidative and reductive characteristics, suggesting their potential as a reagent for repeated detection of H2O2. Moreover, a colorimetric sensing system enabled the liner detection of H2O2 spanning a concentration range from 0.08 to 1 mM, with a detection limit of 0.03 mM. Noteworthily, FFB-Ce-FeONPs demonstrated sustained efficacy over ten successive recycling cycles, as indicated by consistent slopes and observable color changes. In summary, this work reports the first application of nanoenzymes in repetitive H2O2 detection. Even after ten multiple cycles, the detection limit remains virtually unaltered, underscoring the robustness and enduring effectiveness of the engineered nanomaterial. The proposed simultaneous oxidation and reduction strategies for detecting H2O2 showed a commendable capability in ten cycles of H2O2 detection, thus providing a promising approach in the field of H2O2 detection.

Boron-Nitrogen-Edged Biomass-Derived Carbon: A Multifunctional Approach for Colorimetric Detection of H2O2, Flame Retardancy, and Triboelectric Nanogenerator.

Enhancing the concentration and type of nitrogen (N) dopants within the Sp2-carbon domain of carbon recycled from biomass sources is an efficient approach to mimic CNT, GO, and rGO to activate oxidants such as H2O2, excluding toxic chemicals and limiting reaction steps. However, monitoring the kind and concentration of N species in the Sp2-C domain is unlikely with thermal treatments only. A high temperature for graphitization reduces N moieties, leading to low electron density. This inhibits H2O2 adsorption and activation on catalyst surfaces. In this study, coffee waste (CW) is converted into B, N-doped biochar (BXNbY) using boric acid-assisted pyrolysis (H3BO3mass = X and carbonization temperature = Y) under N2 to overcome the challenge. The B dopant regulates the concentration and type of N, provides Lewis's acid sites, and converts graphitic-N to pyridine-N in BXNbY. The optimized B3Nb900 exhibits excellent colorimetric sensing performance toward H2O2 with a low detection limit (36.9nM) and high selectivity in the presence of many interferences and milk samples due to high pyridinic-N and Sp2 domain sizes. Interestingly, B enhances other properties of N-containing CW-derived carbon and introduces self-extinguishing and tribopositive properties. Hence, BXNbY-coated polyurethane foam shows excellent flame retardancy and energy harvesting performance.

Detection of H2O2 and catalase on a paper-based flow sensor constructed with borate cross-linked PVA hydrogel

The detections of H2O2 and catalase play an important role in daily life. This study introduces a paper-based flow sensor that is specifically designed to detect H2O2 and catalase. The sensor utilizes a hydrogel composed of cross-linked 4-carboxyphenylboronic acid and polyvinyl alcohol. When H2O2 is in contact with the hydrogel, the B–C bonds of the hydrogel undergo a reactive process, causing decomposition of the hydrogel. The pH indicator strip enables the visual monitoring of the viscosity change that occurs during the gel-sol transition. The quantification of H2O2 is accomplished by assessing the proportion of water coverage on the pH indicator strip. The sensor shows a detection limit of 0.077 wt% and is applicable for the quantitative measurement of H2O2 in routinely used disinfectants. Furthermore, the presence of catalase is effectively identified and the detection of catalase in milk is successfully fulfilled. In summary, this work proposes a simple, user-friendly, label-free, and cost-effective method for constructing a paper-based flow sensor using borate cross-linked polyvinyl alcohol hydrogel, showing great potential for detecting H2O2 and catalase in various practical scenarios.

One-Pot Synthesis of Nanoflower-Like Zn2SnS4 as Nanozymes for Highly Sensitive Electrochemical Detection of H2O2 Released by Living Cells.

The sensitive and reliable nanozyme-based sensor enables the detection of low concentrations of H2O2 in biological microenvironments, it has potential applications as an in-situ monitoring platform for cellular H2O2 release. The uniformly dispersed bimetallic sulfide (Zn2SnS4) nanoflowers were synthesized via a one-pot hydrothermal method and the two kinds of metal ions can serve as morphology and structure directing agents for each other in the synthetic process. The nanoparticles were utilized as nanozyme materials to fabricate a novel electrochemical sensor, and it exhibits a distinct electrochemical response towards H2O2 with excellent stability and detection capability (with a minimum detection limit of 1.79 nM (S/N=3)), the excellent characteristics facilitate the precise detection of low concentrations of H2O2 in biological microenvironments. Use the macrophages differentiated from leukemia THP-1 cells as a representative sensing model, the sensor was successfully utilized for real-time monitoring of the release of H2O2 induced by living cells, which has significant potential applications in clinical diagnosis and cancer treatment.

Luminescent gold nanoclusters loaded on iron metal–organic framework with enhanced peroxidase-like activity for the colorimetric/fluorescent determination of H2O2

In this work, a composite nanozyme, termed AuNCs/Fe-MIL, was obtained by combining glutathione-stabilized gold nanoclusters (AuNCs) on the surface of the Fe metal–organic framework (Fe-MIL-88B-NH2). The AuNCs/Fe-MIL nanocomposite retains the red emission of AuNCs, exhibiting unique dual-emission fluorescence with remarkable stability. This nanozyme exhibits improved peroxidase-like activity as a result of the heightened rate of electron transfer. As a result, the decomposition of H2O2 is accelerated, leading to the generation of more •OH radicals that oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) into blue ox-TMB. The generated ox-TMB can quench the fluorescence of AuNCs/Fe-MIL in the red-light region. By leveraging the dual function of the catalytic product ox-TMB, a fusion of colorimetric and fluorescence signals enabled H2O2 detection within 10 min. The sensing platform demonstrated wide linear ranges of 5–1000 μM with a detection limit of 2.78 μM in colorimetry mode and 5–500 μM with a detection limit of 0.78 μM in fluorescence mode. This method was successfully utilized for accurate in situ monitoring of H2O2 release from different types of living cells. Additionally, a dual-mode portable sensing platform based on AuNCs/Fe-MIL/TMB hydrogel was constructed for convenient H2O2 detection. Through a smartphone application, precise quantitation of H2O2 added to milk samples was achieved. This work provides a rational design of multifunctional nanozymes for reliable biomimetic catalysis.

A Novel MXene@MOF@Pt NPs-Based Enzyme-Free Electrochemical Sensor for Highly Sensitive Detection of Hydrogen Peroxide Released from Living Cells

Rapid and accurate detection of hydrogen peroxide (H2O2), an important reactive oxygen species (ROS) released from living cells, is of great significance for early diagnosis of tumors. Here, a high sensitive enzyme-free electrochemical sensor for the detection of H2O2 released from living cells was constructed based on MXene@ZIF-8@Pt NPs nanocomposites. Through the characterization of physical and chemical properties, it was observed that Pt NPs with excellent catalytic activity were uniformly supported on MXene@ZIF-8, which exhibited excellent conductivity and large specific surface area. Thanks to the significantly enhanced catalytic activity derived from the successful integration of MXene, ZIF-8 and Pt NPs, under the optimal conditions, the sensing platform based on MXene@ZIF-8@Pt NPs exhibited a wide linear range from 355.4 nM to 21.75 mM, with a limit of detection as low as 120.9 nM, while showing satisfactory reproducibility and selectivity. Furthermore, the developed electrochemical sensor enables real-time monitoring of H2O2 released from living Hela cells under N-formylmethionyl-leucyl-phenylalanine stimulation. Overall, the MXene@ZIF-8@Pt NPs developed in this article will become a promising candidate in monitoring physiological processes.

One-pot synthesis and hydrogen peroxide electrochemical sensing of 3D TiO2/MnO2 nanorods assembled microspheres.

Nanorods assembled 3D microspheres of TiO2/MnO2 were prepared via a simple one-pot hydrothermal approach. The resultant composite material exhibited remarkable electrocatalytic activity for hydrogen peroxide (H2O2) in comparison to each single component. The electrochemical sensor constructed with TiO2/MnO2 exhibited a linear relationship within the range 0.0001-5.6 mmol·L-1 for H2O2. The limit of detection (LOD) and sensitivity for H2O2 were 0.03 µmol·L-1 (S/N = 3) and 316.6 µA (mmol·L-1)-1cm-2. Moreover, this sensor can be employed to detect trace amount of H2O2 in serum and urine samples successfully, supporting an insight and strategy for a more sensitive electrochemical sensor.

A fluorescence probe with targeted mitochondria was developed for detecting H2O2 in vitro and vivo

We designed and developed the probe P-1 for detecting H2O2. The probe can selectively detect H2O2 with colorimetric change. In addition, the combination of portable test strips with a smartphone platform provided great convenience for on-site and visual detection of H2O2 with satisfactory sensitivity and reliability. The P-1 can image exogenous and endogenous H2O2 in cells and distinguish cancer cells and normal cells by fluorescence image of H2O2 and flow cytometry. Meanwhile, the P-1 probe has been successfully applied to monitor H2O2 levels of tumor in mice, and the results showed the level of H2O2 in tumor tissue increased significantly. Therefore, P-1 provided a potential chemical tool to understand pathological and physiological mechanisms of diseases by imaging H2O2.

A near-infrared fluorescent probe based FRET for ratiometric sensing of H2O2 and viscosity in live cells

Hydrogen peroxide (H2O2) and viscosity play vital roles in the cellular environment as signaling molecule and microenvironment parameter, respectively, and are associated with many physiological and pathological processes in biological systems. We developed a near-infrared fluorescent probe, CQ, which performed colorimetric and ratiometric detection of H2O2 and viscosity based on the FRET mechanism, and was capable of monitoring changes in viscosity and H2O2 levels simultaneously through two different channels. Based on the specific reaction of H2O2 with borate ester, CQ exhibited a significant ratiometric response to H2O2 with a large Stokes shift of 221 nm, a detection limit of 0.87 μM, a near-infrared emission wavelength of 671 nm, a response time of 1 h, a wide detection ranges of 0.87–800 μM and a high energy transfer efficiency of 99.9 %. CQ could also recognize viscosity by the TICT mechanism, and efficiently detect viscosity changes caused by food thickeners. More importantly, CQ could successfully detect endogenous/exogenous H2O2 and viscosity in live HeLa cells, which was expected to be a practical tool for detecting H2O2 and viscosity in live cells.

Silicene's intriguing nanozymatic activity: Improved colorimetric and electrochemically supported colorimetric biosensing

Silicene is a material that is largely studied via theoretical models. In the practical world, lengthy incubation times and poor sensitivity of colorimetric detection methods have limited their implementation. This paper transforms silicene's theoretical advantages into practical applications, presenting it as a tangible solution for significantly improving colorimetric biosensing. More specifically, this paper presents a pivotal breakthrough by not only documenting the remarkable nanozymatic activity of silicene in oxidizing 3,3′,5,5′-Tetramethylbenzidine (TMB) with hydrogen peroxide (H2O2), but also leveraging silicene’s inherent electronic properties to enhance the speed and precision of the peroxidase reaction, thereby improving its performance and advancing applicability. Two detection mechanisms were tested to observe the influence of silicene’s electronic scope; one in the absence and the other in the presence of an externally supplied electric potential. Both were successful in the detection of H2O2 and dopamine. The latter proved to be more favorable as it not only shortened the incubation time from 30 min to 1.5 min but also exhibited lower Limit of Detection (LOD) values. To demonstrate, for dopamine, in a concentration range of 0 – 10 μM, the LOD was 4.13 μM without the electric potential and 2.21 μM with the electric potential. Similarly, in a second concentration range, the LOD values were 37.81 μM and 34.94 μM, respectively. Kinetic profiles indicated the superior affinity silicene has for TMB and H2O2. A selectivity test also indicated that the method has excellent selectivity towards dopamine.

Catalase‐functionalized ZnO and graphene oxide used as electrocatalyst for the selective detection of hydrogen peroxide

AbstractBACKGROUNDThis study focuses on the fabrication of a biosensor for the electrocatalytic and selective hydrogen peroxide (H2O2) recognition with bovine liver catalase (CAT) immobilized over a cysteine (c) modified zinc oxide nanoparticles/graphene oxide (c‐ZnO/GO) interface. The selectivity and sensitivity of the biosensor were augmented by the use of CAT and GO, respectively. The problem of CAT activity inhibition by GO was specifically solved by the incorporation of ZnO. Also, the cystine functionalization helped in better immobilization of CAT.RESULTSThis unique approach was first validated with in silico computations that calculated the binding affinities to study the interactions between different components of the biosensor. The electrochemical studies confirmed the step‐by‐step modification of the sensor, where along with GO, c‐ZnO nanoparticles also showed excellent electro‐conductivity by fundamentally improving the peak currents towards H2O2. The proposed bio‐nano interface exhibited superb electrocatalytic performance and specific detection capability for H2O2 across a broad linear range (0.1 to 40 μmol L−1), featuring a low detection limit (0.1 μmol L−1), as well as commendable reproducibility and storage durability. Furthermore, the biosensor yielded satisfactory outcomes for H2O2 detection in milk samples.CONCLUSIONSensing performance of nano‐bio interfaces can be augmented by using the appropriate nano‐composites and their efficacy confirmed through computational techniques such as molecular docking. The biosensor can be further repurposed into a wearable device by integration with lab‐on‐a‐chip platforms. © 2024 Society of Chemical Industry (SCI).

Core-shell structure N-doped graphene quantum dots Fe3O4/Co3O4 nanoparticles for colorimetric detection of H2O2

Hydrogen peroxide (H2O2) is an environmentally friendly intermediate in the environmental field and also plays an important role in human metabolism, but the production and accumulation of excessive H2O2 will cause harm to the human body, resulting in serious damage to cells. Therefore, N-doped graphene quantum dots Fe3O4/Co3O4 nanoparticles with core-shell structure were prepared by in-situ synthesis and precipitation. The experimental results show that the prepared Co3O4 nanoparticles have more efficient peroxidase activity than Co3O4 nanoparticles alone. It can catalyze the oxidation of 3, 3, 5, 5-tetramethylbenzidine (TMB) to produce a blue product (TMBox) in the presence of H2O2. In addition, Co3O4 with negative charge in the shell can produce a strong electrostatic driving coordination effect with positively charged TMB, which enhances the affinity between the nanoparticles and the substrate, and selectively catalyzes H2O2 oxidation of colorless TMB to turn it blue. Based on these experimental results, a simple, low-cost, and efficient colorimetric method for H2O2 detection was established, which showed a sensitive response to H2O2 in the range of 0.02–2.5 μM with a detection limit of 2.3 nM. In addition, due to the magnetic properties of the prepared nanoparticles, they could be easily recovered by applying a magnetic field. This research provides a viable approach for magnetic nanomaterials with encouraging prospects for environmental monitoring, biosensing, and more.

Flexible Co-Ni nanocomposites in situ synthesized on carbon fibers for highly sensitive electrochemical detection of H2O2

In this study, Co-Ni nanomaterials were in situ synthesized on carbon fiber paper substrates, termed Co-Ni paper. Scanning electron microscopy characterization demonstrates fabricated flake-like Co-Ni nanocomposites uniformly distribute on carbon fibers, forming three-dimensional continuous network structure. The fabricated sample is determined to be a mixture of Co, Ni and C elements according to energy-dispersive X-ray spectrometer analysis. Without any pretreatments, Co-Ni paper exhibits excellent electro-oxidation capabilities towards H2O2, such as an excellent detecting performance in a wide linear range of 0‒11.5 mM of H2O2, fast amperometric responses within 1 s, and a low detection limit of 2.53 µM. Along with these intriguing properties, the in situ-synthesized Co-Ni paper has a good anti-interference towards Na2SO4, ZnCl2, glucose and NaCl during H2O2 detection. Moreover, the H2O2 electro-chemical sensor on Co-Ni paper also possesses excellent reproducibility, long-term stability and high mechanical stability. This Co-Ni-paper-based sensor is effective to determine H2O2 in blood samples, thus it is promising for electrochemical H2O2 sensing.

Paper-based enzyme-linked biosensor combined with smartphone for simultaneous colorimetric sensing of xanthines and sarcosine

A portable paper-based enzyme-linked biosensor that integrates a multi-enzyme cascade reaction, natural enzyme, and nanozyme with filter paper, combined with smartphones, is proposed for the detection of xanthine (XA) and sarcosine (SA) in urine. The primary biological component of the sensor is horseradish peroxidase (HRP). By chemically modifying cellulose filter paper (CFP) the HRP in horseradish crude extract is specifically immobilized through boron affinity and metal chelation techniques. Furthermore, the incorporation of UiO-66 on CFP had a good synergistic effect on the electron transfer of HRP and the detection of H2O2, significantly increasing the sensor's sensitivity. Under optimized experimental conditions, the sensor demonstrated a dynamic response range of 8–400 μmol L−1 for SA with a minimum detection limit (LOD) of 5 μmol L−1, and a dynamic response range of 10–400 μmol L−1 with an LOD of 8 μmol L−1 for XA. Additionally, the well-designed detection area of the portable test strip simplifies the detection operation, reduces the detection time, and enables rapid on-site analysis. UV-Vis analysis further confirmed the sensor's accuracy in detecting disease markers in urine. The sensing platform has good reproducibility, specificity and stability, suitable for the detection of SA and XA in real human urine samples, and the sensor has the advantages of simple manufacturing, easy operation, strong portability, low reagent consumption, and low cost benefit. Therefore, the development of this paper-based enzyme-linked biosensor offers a novel approach to the detection of disease markers in urine and has potential applications in medical testing.

A flexible self-supported electrochemical sensor Co-NC/PS@CC for real-time detection of cell-released H2O2

BackgroundHydrogen peroxide (H2O2) is an important reactive oxygen species (ROS) molecule involved in cell metabolism regulation, transcriptional regulation, and cytoskeleton remodeling. Real-time monitoring of H2O2 levels in live cells is of great significance for disease prevention and diagnosis. ResultsWe utilized carbon cloth (CC) as the substrate material and employed a single-atom catalysis strategy to prepare a flexible self-supported sensing platform for the real-time detection of H2O2 secreted by live cells. By adjusting the coordination structure of single-atom sites through P and S doping, a cobalt single-atom nanoenzyme Co-NC/PS with excellent peroxidase-like activity was obtained. Furthermore, we explored the enzyme kinetics and possible catalytic mechanism of Co-NC/PS. Due to the excellent flexibility, high conductivity, strong adsorption performance of carbon cloth, and the introduction of non-metallic atom-doped active sites, the developed Co-NC/PS@CC exhibited ideal sensing performance. Experimental results showed that the linear response range for H2O2 was 1–17328 μM, with a detection limit (LOD) of 0.1687 μM. Additionally, the sensor demonstrated good reproducibility, repeatability, anti-interference, and stability. SignificanceThe Co-NC/PS@CC prepared in this study has been successfully applied for detecting H2O2 secreted by MCF-7 live cells, expanding the application of single-atom nanoenzymes in live cell biosensing, with significant implications for health monitoring and clinical diagnostics.

Highly sensitive biofunctionalized nanostructures for paper-based colorimetric sensing of hydrogen peroxide in raw milk

Hydrogen Peroxide (H2O2) is a highly hazardous, toxic, and carcinogenic chemical compound utilised in various industries-based applications. Despite strict restriction, they are deliberately added to food items such as milk as preservatives to increase its shelf life. Herein, we have formulated a green rapid colorimetric nanosensor for detection of H2O2 in milk using cotton leaves as both reducing and functionalizing agent for synthesis of silver nanoparticles (AgNPs). UV–Vis spectra exhibit a strong plasmonic peak at around 434 nm. X-Ray Diffraction (XRD) analysis was performed to determine the crystallinity of the nanoparticles. Field Emission Scanning Electron Microscope (FESEM) and Transmission Electron Microscope (TEM) characterizations revealed spherical morphology with size approximately ∼16 nm. This functionalized nanoparticle could colorimetrically sense presence of H2O2 in milk samples both in liquid media and on paper substrates with Limit of Detection (LOD) of 8.46 ppm even in presence of other interfering substances in milk. This inexpensive route will pave the way for in depth research.

A novel flexible electrochemical sensor with multi-level carbon nano-array for in-situ real-time monitoring of H2O2 secreted by cells

Developing ultra-sensitive sensors for in-situ real-time monitoring of low-level cell secretions is of paramount importance in understanding various biological processes, and it is still a challenge. Herein, for the first time, we constructed a novel flexible Au-Co@C-CNT/CC sensing electrode with nano-array structures by in-situ synthesis, catalytic pyrolysis and electrochemical deposition, and successfully realized the real-time monitoring of H2O2 released by cells. The 3D leaf-like structure of the electrode not only provided a large electroactive surface area (7.66 cm2) but also exhibited a microvilli structure of carbon nanotubes (CNT) on the surface, which further enhanced the presence of active sites. Moreover, the Co-Nx sites generated by catalytic pyrolysis can promote the adsorption and catalysis of H2O2 on the surface of sensing electrode. The introduction of Au NPs facilitated the transfer of electrons, thereby enhancing the electrical conductivity and electrocatalytic performance of Au-Co@C-CNT/CC. Benefiting from these unique superiorities, this sensing platform displayed excellent performance for H2O2 determination with a wide linear range (10–27080 μM) and low detection limit (0.13 μM). Notably, the good biocompatibility and flexibility of this sensing platform allowed direct culture of human lung cancer cells (A549 cells) on the electrodes, which can realize dynamic in-situ real-time detection of H2O2 released by cells, showing great potential in the diagnosis of related diseases.

Prunella vulgaris-phytosynthesized platinum nanoparticles: Insights into nanozymatic activity for H2O2 and glutamate detection and antioxidant capacity

Artificial nanozymes (enzyme-mimics), specifically metallic nanomaterials, have garnered significant attention recently due to their reduced preparation cost and enhanced stability in a wide range of environments. The present investigation highlights, for the first time, a straightforward green synthesis of biogenic platinum nanoparticles (PtNPs) from a natural resource, namely Prunella vulgaris (Pr). To demonstrate the effectiveness of the phytochemical extract as an effective reducing agent, the PtNPs were characterized by various techniques such as UV–vis spectroscopy, High-resolution Transmission electron microscopy (HR-TEM), zeta-potential analysis, Fourier-transform infrared spectroscopy (FTIR), and Energy dispersive spectroscopy (EDS). The formation of PtNPs with narrow size distribution was verified. Surface decoration of PtNPs was demonstrated with multitudinous functional groups springing from the herbal extract. To demonstrate their use as viable nanozymes, the peroxidase-like activity of Pr/PtNPs was evaluated through a colorimetric assay. Highly sensitive visual detection of H2O2 with discrete linear ranges and a low detection limit of 3.43 μM was demonstrated. Additionally, peroxidase-like catalytic activity was leveraged to develop a colorimetric platform to quantify glutamate biomarker levels with a high degree of selectivity, the limit of detection (LOD) being 7.00 μM. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) test was used to explore the scavenging nature of the PtNPs via the degradation of DPPH. Overall, the colorimetric assay developed using the Pr/PtNP nanozymes in this work could be used in a broad spectrum of applications, ranging from biomedicine and food science to environmental monitoring.