An electrochemical sensor based on N-doped hollow carbon sphere@ZIF-8 composite for luteolin detection

doi:10.21203/rs.3.rs-4708576/v1

Download PDF

Article

An electrochemical sensor based on N-doped hollow carbon sphere@ZIF-8 composite for luteolin detection

https://doi.org/10.21203/rs.3.rs-4708576/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

In the study, a composite carbon nanomaterial (NC@ZIF-8) based on N-doped hollow carbon spheres and a metal-organic framework (ZIF-8) material was developed to prepare an electrochemical sensor for the detection of luteolin, a natural flavonoid with favorable pharmacological properties, including anti-inflammatory, antibacterial, and antioxidant properties. Owing to its high specific surface area, high conductivity, and abundant active sites, the NC@ZIF-8 composite exhibited excellent luteolin detection performance, including a wide linear range, good repeatability, and immunity to interference. The synthesis and characterization of the material and the fabrication and optimization of the electrochemical sensor are described. The NC@ZIF-8/GCE sensor exhibited good recovery and stability in detecting luteolin in real samples, demonstrating its effectiveness in the rapid and accurate detection of luteolin.

Physical sciences/Nanoscience and technology/Nanoscale materials/Nanoparticles

Physical sciences/Materials science/Nanoscale materials/Nanoparticles

luteolin

electrochemical sensors

composites

N-doped hollow carbon spheres

In the modern food industry and in medicine, there is a growing demand for the detection and analysis of natural compounds. Luteolin (3,4,5,7-tetrahydroxy-alone) is a natural flavonoid, widely distributed in plants and fruits, such as celery, oranges, apples, etc[1]. Luteolin is a natural drug with many pharmacological activities, including uric acid-lowering, antibacterial, antitumor, anti-inflammatory, etc. In the food industry, it is regarded as an important food additive due to its good antioxidant and anti-inflammatory properties, which are used to improve the nutritional value and extend the shelf life of food.

In order to detect luteolin levels in food, it is important to develop a rapid, accurate, and convenient detection method. At present, the main detection methods for luteolin are high-performance liquid chromatography^[2], ultraviolet-visible spectrophotometer^[3], capillary electrophoresis^[4], etc. Although these methods are highly accurate, the disadvantages of expensive instruments, complex operation, and long detection time also make the detection of luteolin costly. In recent years, electrochemistry has entered the field of vision due to its advantages of simple equipment, simple operation, low cost, high reliability, and fast response speed, and is considered to be an ideal alternative method^[5].

Metal-organic framework materials (MOFs). It has unique structural characteristics, including high specific surface area, tunable pore size and functionalization, and diverse chemical properties, which make it have great potential in catalysis, adsorption, separation, sensors, and other fields^[6]. As a Zn-based MOF material, ZIF-8 is widely used in gas storage, separation, catalysis, and electrochemical sensing due to its unique properties and mild synthesis conditions^[7].

As an advanced nanomaterial, N-doped hollow carbon spheres (N-CSSs) combine the high conductivity and chemical stability of carbon materials by introducing nitrogen atoms into carbon spheres to form special doped carbon materials^[8]. The large-scale preparation of these materials usually adopts the hard template method, using silicon dioxide (SiO₂) as a template, coated with dopamine hydrochloride, and then carbonized at high temperature in a tube furnace to form carbon balls, forming hollow carbon balls by etching templates, and then uniformly growing ZIF-8 inside and outside the carbon balls by in-situ growth method, which effectively avoids the problem of crystal aggregation.

In this study, we developed a composite carbon nanomaterial (NC@ZIF-8) based on nitrogen-doped hollow carbon spheres and ZIF-8 for the preparation of electrochemical sensors for the detection of luteolin. This material exhibits excellent detection performance due to its high specific surface area, high conductivity, and abundant active sites. We describe in detail the synthesis and characterization process of materials, as well as the preparation and optimization methods of electrochemical sensors. The experimental results showed that the NC@ZIF-8/GCE sensor had good recovery and stability in the actual sample detection, which provided an effective method for the rapid and accurate detection of luteolin.

In addition, we conducted a comprehensive evaluation of the electrochemical properties of NC@ZIF-8 composites, including cyclic voltammetry (CV), chronocoulometric (CC), current-time curve (I-T), and differential pulse voltammetry (DPV). With these methods, we have optimized the detection conditions and improved the sensitivity and accuracy of the detection. We also investigated the anti-interference capability of the material, demonstrating that the NC@ZIF-8/GCE sensor can accurately and reliably detect luteolin in the presence of multiple potential interfering substances in real-world sample detection.

Finally, we verified the practical application capability of the NC@ZIF-8/GCE sensor in honeysuckle extract and watermelon juice by the standard addition method. The results showed that the sensor had excellent repeatability and reproducibility, with recoveries ranging from 95.41–101.20%, proving its effectiveness and reliability in actual sample detection. These results not only demonstrate the application potential of NC@ZIF-8 composites in the field of electrochemical sensors but also provide a scientific basis for practical applications in the fields of food safety testing and pharmaceutical analysis in the future.

2.1 Materials

Ethanol (98%), deionized water, ammonia, tetraethyl silicate (98%, Purchased from Shanghai McLean Biochemical Technology Co., Ltd), dopamine hydrochloride (98%; Purchased from Shanghai McLean Biochemical Technology Co., Ltd), sodium hydroxide (NaOH, analytically pure), 2-methylimidazole (Purchased from Shanghai McLean Biochemical Technology Co., Ltd), zinc nitrate hexahydrate (Zn(NO₃)₂∙6H₂O), triethylamine, isopropanol (analytically pure), and 5% Nafion were used in this study. Phosphate buffered saline (PBS, 0.1 M) was prepared from Na₂HPO₄ and NaH₂PO₄, and the pH was adjusted using H₃PO₄ and KOH. All reagents were used as received, without further purification, and all solutions were prepared using ultrapure water.

2.2. Synthesis of hollow carbon spheres

First, a mixed solution of ethanol (300 mL), deionized water (90 mL), and ammonia (15 mL) was stirred at room temperature for 30 min. Then, tetraethyl silicate (15 mL) was added to the above solution, and the resulting mixture was stirred vigorously for 1 h, during which silica particles were formed. Thereafter, dopamine hydrochloride (1.5 g) was added to the silica particle suspension, and the resulting mixture was stirred for 12 h. The final product was centrifuged and dried.

The product obtained from the previous reaction was placed in a tube furnace and heated to 900°C at 3°C/min and maintained there for 3 h. Then, the carbonized product was placed in a 4 M NaOH solution, and silica was etched away over 24 h to obtain N-doped hollow carbon spheres.

2.3. Synthesis of NC@ZIF-8

N-doped hollow carbon spheres (0.3 g) and 2-methylimidazole (0.06 g) were placed in a 50 mL round-bottom flask. Then, deionized water (25 mL) and ethanol (25 mL) were added, the reactants were ultrasonically dispersed, and the mixture was subjected to rotary evaporation for 1.5 h. Thereafter, zinc nitrate (0.06 g) and deionized water (3 mL) were added to the flask, and the contents were again subjected to rotary evaporation for 2 h, and triethylamine (100 µL) was added. The mixture was heated in a water bath at 60°C for 6 h to evaporate the solvent, and the product was collected by centrifugation, washed with ethanol and water, and dried to obtain NC@ZIF-8. The preparation of the composite is illustrated in Fig. 1.

2.4. Preparation of NC@ZIF-8/GCE

Bare GCE was polished with α-Al₂O₃ powder (0.05 µm), rinsed with ultrapure water and ethanol, and finally dried with nitrogen. Then, an appropriate amount of NC@ZIF-8 was taken in a 10 mL centrifuge tube, measured volumes of deionized water (600 µL), isopropanol (350 µL), and 5% Nafion solution (50 µL) were added using a pipette, and the resulting mixture was sonicated for 5 min. Subsequently, 5 µL of the suspension was gently dropped on the surface of a GCE and naturally dried to obtain the NC@ZIF-8/GCE sensor.

2.5. Electrochemical analysis

Electrochemical tests were performed using a CHI 660E potentiostat (CH Instruments). A typical three-electrode system consisting of a bare carbon or modified glassy carbon electrode (GCE) as the working electrode, a platinum wire as the auxiliary electrode, and a saturated Ag/AgCl reference electrode was used.

Various electrochemical analyses were carried out on NC@ZIF-8 using chronocoulometry (CC), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The CC experiment was conducted in the voltage range of 0 to 0.25 V. The CV method experiment was carried out in the voltage range of 0.1 to 0.8 V. DPV was carried out in the voltage range of − 0.2 to + 1.0 V.

2.6. Material characterization

The surface morphology and structure of the prepared materials were investigated using scanning electron microscopy (SEM; Hitachi SU8220) and transmission electron microscopy (TEM; JEOL JEEM-2100). The crystal structures of the samples were evaluated through X-ray diffraction (XRD; Bruker D8 Advance) conducted using Cu radiation. The elemental composition and distribution of the composite materials were analyzed by energy-dispersive X-ray spectroscopy and the surface valence states of the materials were analyzed by thermal resistance 250Xix X-ray photoelectron spectroscopy (XPS).

3.1. Characterization of the materials

The morphologies of the obtained materials (hollow carbon spheres and the NC@ZIF-8 composite) were observed using TEM. Figure 2(a) shows that the surface of the hollow carbon sphere is very regular and does not have other structures attached. The hollow carbon spheres are distinguishable, indicating their successful synthesis using SiO₂ particles as the template. The TEM image of the NC@ZIF-8 composite (Fig. 2(b)) reveals that some crystals are attached to the surface of the hollow carbon spheres, and the crystals present a regular octahedral structure, which is consistent with the typical morphology of ZIF-8 crystals ^[9]. It can therefore be concluded that the synthesis of ZIF-8 crystals on hollow carbon spheres by the in situ growth method was successful, and the synthesized crystals grew irregularly on the surface of the hollow carbon spheres. To further investigate the crystal phase, the morphologies of the synthesized materials were characterized by SEM. The SEM image of the carbon spheres in Fig. 2(c) shows that the surface of the hollow carbon sphere is covered with crystals, and the crystals are evenly distributed, not only on the surface of the hollow carbon sphere but also inside it. This is because some of the spheres cracked during the synthesis, and the ZIF-8 crystals were adhered to the inner walls of such spheres. Figure 2(d) reveals that the silica particle template used to synthesize the carbon sphere was completely etched by sodium hydroxide, resulting in a uniform hollow carbon sphere with a neat surface, which corresponds to the TEM results. These SEM results are in good agreement with the TEM results.

Figure 3 shows the XRD pattern of the NC@ZIF-8 composite, in which the peaks observed at 2θ = 7.29, 10.34, 12.69, 14.66, 16.38, and 17.99 are attributable to the (001), (002), (112), (022), (013), and (222) planes of the ZIF-8 crystal, respectively. These peaks indicate the successful formation of the MOF crystals on the hollow carbon sphere ^[10]. However, the diffraction peaks of the hollow carbon sphere were not observed in the XRD pattern, probably because of their relatively low peak intensity compared with that of the ZIF-8 crystal peaks, which caused the diffraction peak of the hollow carbon sphere to be hidden. The XRD pattern of the NC@ZIF-8 composite is consistent with that of the standard card, indicating that the desired material was successfully produced ^[11].

The functional groups of the NC@ZIF-8 composites were analyzed using X-ray photoelectron spectroscopy (XPS). As shown in Fig. 4(a), the composite contains four elements: C, N, O, and Zn. Figure 4(b) shows that the C1s peak can be deconvoluted into five characteristic peaks at 284.6, 285.4, 286.6, 287.8, and 289 eV, corresponding to C = C, C-N, C-O, C = O, and O-C = O linkages ^[12]. Figure 4(c) shows that the O1s peak can be deconvoluted into three peaks that represent C = O, C-OH, and C-O ^[13] bonds at 531.4, 532.3, and 533.4 eV, respectively. Figure 4(d) shows the fitting of the N1s peak with three components corresponding to pyridinic, pyrrolic, and graphitic N atoms at 398.2, 399.9, and 500.9 eV, respectively ^[14].

3.2. Brunauer-Emmett analysis of the composite

To determine the specific surface area and material type, the BET analysis of the nitrogen adsorption-desorption curve of the NC@ZIF-8 composite was performed (see Fig. 5(a)). The adsorption capacity of the material increased rapidly under low relative pressures and tended to be stable after reaching a certain pressure, but it increased again at higher pressures. Compliance with type IV isotherms indicates that the material has a mesoporous structure ^[15]. Through BET analysis, the specific surface area of the composite was determined to be 175.8756 m²/g. As shown in Fig. 5(b), the pore size of the NC@ZIF-8 composite was mainly concentrated in the range of 2–16 nm, and the pore size range of this mesoporous material was 2–50 nm, which is consistent with the isothermal adsorption results.

3.3. Optimization of electrochemical conditions

For the electrochemical detection of luteolin using the NC@ZIF-8/GCE, the most important experimental parameters, such as the amount of the material used to modify the GCE, enrichment potential, enrichment time, and pH of the buffer were optimized.

Figure 6(a) shows the effect of the amount of NC@ZIF-8 used to modify the GCE on the peak current in DPV measurements. In DPV, the peak current is considerably affected by the amount of the material used for GCE modification. For NC@ZIF-8/GCE, the peak current increased with the increase in the amount of NC@ZIF-8 used in GCE modification, reaching the maximum value at 3 mg/mL. However, when the amount of NC@ZIF-8 used in GCE modification was increased further, the thick layer of the composite formed on the electrode hindered electron transfer, causing the peak current to decrease. Therefore, an NC@ZIF-8 concentration of 3 mg/mL was selected as the optimal one for GCE modification.

To explore the influence of luteolin enrichment time on luteolin detection using the NC@ZIF-8/GCE, the enrichment time was varied between 60 and 180 s (the enrichment potential was fixed at 0.2 V). As shown in Fig. 6(b), the enrichment time affected the peak current. As the enrichment time increased from 60 to 120 s, the peak current increased gradually. When the enrichment time reached 150 s, the electrode surface was saturated. Nevertheless, the peak current increased at a smaller rate. Considering the comprehensive time cost and efficiency, an enrichment time of 120 seconds was selected for further experiments.

Figure 6(c) shows the effect of the enrichment potential on the peak current in the detection of luteolin using the optimized NC@ZIF-8/GCE. The enrichment potential in the range of 0.1–0.5 V was explored; as the enrichment potential was increased from 0 to 0.2 V, the peak current increased significantly and reached the maximum value at 0.2 V. When the enrichment potential was increased further, the peak potential decreased. The optimal enrichment potential in this experiment was 0.2 V, and an enrichment potential of 0.2 V was used in subsequent experiments.

Next, the effect of the buffer pH on the experimental peak current was investigated. As shown in Fig. 6(d), the peak current in the DPV curve increased with an increase in the buffer pH from 3 to 5, reaching the highest value at pH 5. When the buffer pH was increased further, the peak current decreased because of the decreased acidity of the solution and thus the H⁺ concentration, which slowed the electron transport. Subsequent experiments were performed in a buffer solution with pH 5 to optimize the electrochemical detection of luteolin.

3.4. Effects of pH and scan rate

Figure 7(a) shows the DPV curves corresponding to the detection of 10 µM luteolin with an NC@ZIF-8/GCE sensor at different pH values. The solution pH strongly affected the intensity of the detected electrochemical signals. As shown in Fig. 7(a), Epa changed with the solution pH, and when the pH increased from 3 to 7, E_pa shifted in the negative direction. As shown in Fig. 7(b), the peak potential has a good linear response relationship with pH, and the corresponding linear equation is E_pa = − 0.0582pH + 0.6958 (R² = 0.992). The slope of the line is 58.2 mV/pH, which is close to the theoretical value of 59 mV/pH based on the Nernst equation, indicating that the number of protons involved in the reaction is equal to the number of electrons transferred in the reaction ^[16].

To explore the redox reaction mechanism of luteolin, the electron transfer number of the reaction was calculated as 2.3 RT/nF, where R is the gas constant, T is the temperature, F is the Faraday constant, and n is the number of transferred electrons. The electron transfer number calculated based on the peak potential difference in Fig. 7(a) is n = 1.87, which is close to 2 ^[17]. These results indicate that luteolin is involved in the transfer of two protons and electrons in the redox reaction during the electrochemical reaction on the NC@ZIF-8/GCE sensor, and the corresponding electrochemical reaction is shown in Fig. 8 ^[18].

To further study the electrochemical behavior (redox reaction) of luteolin on the NC@ZIF-8/GCE sensor, the effects of different sweep velocities in the range of 30–210 mV/s on the electrochemical peak current were studied by CV. As shown in Fig. 7(c), the oxidation and reduction peak currents corresponding to the redox reaction of luteolin showed a good positive trend with scan rate v. This trend indicates that the electrochemical behavior of luteolin on the NC@ZIF-8/GCE sensor is mainly controlled by the adsorption process ^[19]. Figure 7(d) shows the linear relationship between scan rate v and oxidation peak current, and the linear equation is I_pa (I_pa = 0.07489v − 0.49465 (R² = 0.995)). Similarly, a good linear relationship between the scan rate and reduction peak current was observed, and the linear equation is I_pa = − 0.0456v − 0.03747 (R² = 0.998).

3.5. Electrochemical behavior of luteolin on different electrodes

Figure 9(c) shows the CV curves of the bare GCE and three modified electrodes, viz., hollow carbon sphere/GCE, ZIF-8/GCE, and NC@ZIF-8/GCE. As shown, the NC@ZIF-8/GCE has the largest redox peak, indicating that its electrochemical performance is better than those of the bare electrode and the other two electrodes modified with the components of the composite (hollow carbon spheres and ZIF-8).

To determine the effective areas of the different modified electrodes, the linear relationship between charge Q and t^1/2 was obtained by evaluating the bare GCE and three differently modified electrodes by the CC method (see Fig. 9(a, b)). The effective areas (A) of the four different electrodes were calculated using the Anson equation:

Q = 2nFAcD^1/2t^1/2/п^1/2 + Q_dl + Q_ads ^[20] (1)

Here, F is the Faraday constant (96500 C/mol), c is the substrate concentration, which is 5×10^− 6 mol/cm³, D is the standard diffusion coefficient, for which a value of 7.6×10^− 6 cm²/s was used, Q_dl is the double-layer charge, Q_ads is the Faraday charge, and n is the number of electrons transferred, which was calculated to be 2. Therefore, according to Eq. (1), the active surface areas of GCE, NC/GCE, ZIF-8/GCE, and NC@ZIF-8/GCE are 0.0072, 0.0472, 0.0910, and 0.0943 cm², respectively. Thus, the effective area of the NC@ZIF-8/GCE electrode is significantly larger than those of the other three electrodes, which is more conducive to the enrichment of luteolin.

3.6. Establishment of standard curves

After the optimization experiments, a standard curve was plotted to verify the performance of the composite sensor in luteolin detection via DPV electroanalysis under the optimized conditions. As shown in Fig. 10(a), the oxidation peak current in the DPV experiment increased as the luteolin concentration increased from 0.05 to 30 µM. The oxidation peak current (I_pa) exhibited a good linear relationship with the concentration of luteolin (c), as shown in Fig. 10(b), and the linear equation is I_pa (µA) = 0.99433 c (µM) + 0.92699, R² = 0.9997. The NC@ZIF-8/GCE sensor has a limit of detection (LOD, S/N = 3) of 0.011 µM for luteolin. The experimental results indicate that the prepared NC@ZIF-8/GCE has a good linear concentration range and a low LOD. It is therefore suitable for specific practical applications.

3.7. Repeatability and reproducibility testing of the NC@ZIF-8/GCE

The repeatability and reproducibility of the NC@ZIF-8/GCE sensor were evaluated by conducting DPV under the optimized conditions (Fig. 11). To study the repeatability of the electrode, a freshly prepared NC@ZIF-8/GCE was used in the detection of 10 µM luteolin up to 8 times. To study the reproducibility of the NC@ZIF-8/GCE sensor, eight replicate NC@ZIF-8/GCE sensors were prepared to detect luteolin at 10 µM concentration. The relative standard deviations (RSDs) for repeatability and reproducibility are 2.62 and 1.26%, respectively. These results reveal that the NC@ZIF-8/GCE sensor has good repeatability and reproducibility, and thus has good application potential.

3.8. Anti-interference capability of NC@ZIF-8/GCE in luteolin detection

Under optimal experimental conditions, the anti-interference ability of the NC@ZIF-8 composite in luteolin detection was evaluated by DPV. K⁺, Cl⁻, Mg²⁺, Na⁺, and NO₃⁻ were added at 500-fold, while glucose, fructose, ascorbic acid, mannitol, and citric acid were added at 300-fold to a PBS buffer solution containing 10 µM luteolin (0.1 M), and DPV was conducted under optimal conditions. As shown in Fig. 12, compared with the blank control group without interfering substances, the change range of the peak current for the solutions added with various interfering species was less than 5%, which falls in the normal range. This experimental result demonstrates that the presence of these ions and substances did not interfere with luteolin detection. Therefore, the NC@ZIF-8/GCE chemical sensor can be used for the accurate, reliable, and safe detection of luteolin in actual samples.

3.9. Detection of actual samples

To evaluate the ability of the NC@ZIF-8/GCE sensor to detect luteolin in actual samples, a standard addition method was used for its detection in honeysuckle extract and watermelon juice. Honeysuckle was purchased from a local pharmacy, and watermelons were obtained from a local supermarket. For extraction, 1 g of honeysuckle was suspended in 10 mL of absolute ethanol, the mixture was sonicated for 1 h, and the filtrate was collected. The volume of the test sample was then made up with ethanol solution in a 100 mL volumetric flask. The watermelon was manually squeezed into watermelon juice and filtered, and the clear filtrate was diluted 100 times with aqueous ethanol. The recovery rates of luteolin in honeysuckle extract and watermelon juice samples were 95.41–100.06% and 98.09–101.20%, respectively. These results prove that the NC@ZIF-8/GCE chemical sensor can effectively detect luteolin in actual samples. Thus, the NC@ZIF-8/GCE chemical sensor can be used accurately, reliably, and safely to detect luteolin in actual samples.

Table 1

Detection of luteolin in watermelon juice and honeysuckle extract using the NC@ZIF-8/GCE sensor
Sample	Added (µM)	Found ± SD by DPV (µM)	Recovery (%)
Watermelon juice	0	-	-
	3	3.036 ± 0.146	101.22
	10	9.809 ± 0.261	98.09
	20	19.903 ± 0.750	99.52
Honeysuckle	0	1.338 ± 0.066	-
	3	4.139 ± 0.066	95.41
	10	11.086 ± 0.228	97.78
	20	21.351 ± 0.297	100.06

ZIF-8 was synthesized on hollow carbon spheres using the original growth method to form an NC@ZIF-8 composite, which was then characterized by SEM, TEM, BET, XPS, XRD, and various electrochemical techniques, such as CV, DPV, and CC. Comprehensive structural characterization using various techniques indicated that the composite was successfully produced. The specific surface area of the hollow carbon sphere was significantly increased after the formation of ZIF-8 crystals on its surface, and more active sites were added to enhance its electrochemical catalytic activity. The outstanding performance of the NC@ZIF-8 composite in the detection of luteolin in analytical samples was further verified. In addition, its excellent performance in the presence of interfering agents and good stability in terms of repeatability and reproducibility were verified. The NC@ZIF-8 sensor exhibited a good linear range and a low LOD in luteolin detection. Finally, the NC@ZIF-8 sensor achieved good recovery in the detection of luteolin in watermelon juice and honeysuckle extract. Thus, the sensor developed in this study is expected to be an ideal candidate for determining luteolin in real samples.

Zhang L, Qin D, Feng J, et al. Rapid quantitative detection of luteolin using an electrochemical sensor based on electrospinning of carbon nanofibers doped with single-walled carbon nanoangles[J]. Analytical Methods, 2023, 15(25): 3073-3083. https://doi.org/10.1039/D3AY00497J
Richard, S.; Hladnik, L.; Vicente, F. A.; Srčič, S.; Grilc, M.; Likozar, B., Solubility of Luteolin and Other Polyphenolic Compounds in Water, Nonpolar, Polar Aprotic and Protic Solvents by Applying FTIR/HPLC. Processes 2021,9 (11). http://dx.doi.org/10.3390/pr9111952.
Skoko, S.; Ambrosetti, M.; Giovannini, T.; Cappelli, C., Simulating Absorption Spectra of Flavonoids in Aqueous Solution: A Polarizable QM/MM Study. Molecules 2020,25 (24). http://dx.doi.org/10.3390/molecules25245853.
Wang, S.-P.; Huang, K.-J., Determination of flavonoids by high-performance liquid chromatography and capillary electrophoresis. Journal of Chromatography A 2004,1032 (1-2), 273-279. http://dx.doi.org/10.1016/j.chroma.2003.11.099.
Gao, F.; Tu, X.; Ma, X.; Xie, Y.; Zou, J.; Huang, X.; Qu, F.; Yu, Y.; Lu, L., NiO@Ni-MOF nanoarrays modified Ti mesh as an ultrasensitive electrochemical sensing platform for luteolin detection. Talanta 2020,215. http://dx.doi.org/10.1016/j.talanta.2020.120891.
Zhang, Y.; Yuan, S.; Day, G.; Wang, X.; Yang, X.; Zhou, H.-C., Luminescent sensors based on metal-organic frameworks. Coordination Chemistry Reviews 2018,354, 28-45. http://dx.doi.org/10.1016/j.ccr.2017.06.007.
Dai, H.; Yuan, X.; Jiang, L.; Wang, H.; Zhang, J.; Zhang, J.; Xiong, T., Recent advances on ZIF-8 composites for adsorption and photocatalytic wastewater pollutant removal: Fabrication, applications and perspective. Coordination Chemistry Reviews 2021,441. http://dx.doi.org/10.1016/j.ccr.2021.213985.
Liu, C.; Wang, J.; Li, J.; Hu, X.; Lin, P.; Shen, J.; Sun, X.; Han, W.; Wang, L., Controllable synthesis of N-doped hollow-structured mesoporous carbon spheres by an amine-induced Stöber-silica/carbon assembly process. Journal of Materials Chemistry A 2016,4 (30), 11916-11923. http://dx.doi.org/10.1039/c6ta03748h.
Zheng, G.; Chen, Z.; Sentosun, K.; Pérez-Juste, I.; Bals, S.; Liz-Marzán, L. M.; Pastoriza-Santos, I.; Pérez-Juste, J.; Hong, M., Shape control in ZIF-8 nanocrystals and metal nanoparticles@ZIF-8 heterostructures. Nanoscale 2017,9 (43), 16645-16651. http://dx.doi.org/10.1039/c7nr03739b.
Seoane, B.; Zamaro, J. M.; Tellez, C.; Coronas, J., Sonocrystallization of zeolitic imidazolate frameworks (ZIF-7, ZIF-8, ZIF-11, and ZIF-20). CrystEngComm 2012,14 (9). http://dx.doi.org/10.1039/c2ce06382d.
Jin, Y.-f.; Ge, C.-y.; Li, X.-b.; Zhang, M.; Xu, G.-r.; Li, D.-h., A sensitive electrochemical sensor based on ZIF-8–acetylene black–chitosan nanocomposites for rutin detection. RSC Advances 2018,8 (57), 32740-32746. http://dx.doi.org/10.1039/c8ra06452k.
Lakshmanakumar, M.; Nesakumar, N.; Sethuraman, S.; S, R. K.; Krishnan, U. M.; Rayappan, J. B. B., Fabrication of GQD-Electrodeposited Screen-Printed Carbon Electrodes for the Detection of the CRP Biomarker. ACS Omega 2021,6 (48), 32528-32536. http://dx.doi.org/10.1021/acsomega.1c04043.
Wang, C.; Huang, D.; He, F.; Jin, T.; Huang, B.; Xu, J.; Qian, Y., Efficient Removal of Uranium(VI) from Aqueous Solutions by Triethylenetetramine-Functionalized Single-Walled Carbon Nanohorns. ACS Omega 2020,5 (43), 27789-27799. http://dx.doi.org/10.1021/acsomega.0c02715.
Dutta, K.; De, S.; Das, B.; Bera, S.; Guria, B.; Ali, M. S.; Chattopadhyay, D., Development of an Efficient Immunosensing Platform by Exploring Single-Walled Carbon Nanohorns (SWCNHs) and Nitrogen-Doped Graphene Quantum Dot (N-GQD) Nanocomposite for Early Detection of Cancer Biomarker. ACS Biomaterials Science & Engineering 2021,7 (12), 5541-5554. http://dx.doi.org/10.1021/acsbiomaterials.1c00753.
Baldovino-Medrano, V. G.; Niño-Celis, V.; Isaacs Giraldo, R., Systematic Analysis of the Nitrogen Adsorption–Desorption Isotherms Recorded for a Series of Materials Based on Microporous–Mesoporous Amorphous Aluminosilicates Using Classical Methods. Journal of Chemical & Engineering Data 2023,68 (9), 2512-2528. http://dx.doi.org/10.1021/acs.jced.3c00257.
Kumar, A.; Furtado, V. L.; Gonçalves, J. M.; Bannitz-Fernandes, R.; Netto, L. E. S.; Araki, K.; Bertotti, M., Amperometric microsensor based on nanoporous gold for ascorbic acid detection in highly acidic biological extracts. Analytica Chimica Acta 2020,1095, 61-70. http://dx.doi.org/10.1016/j.aca.2019.10.022.
Xie, Y.; Zhang, T.; Chen, Y.; Wang, Y.; Wang, L., Fabrication of core-shell magnetic covalent organic frameworks composites and their application for highly sensitive detection of luteolin. Talanta 2020,213. http://dx.doi.org/10.1016/j.talanta.2020.120843.
Cheng, H.; Li, T.; Li, X.; Feng, J.; Tang, T.; Qin, D., Facile Synthesis of Co9S8 Nanocages as an Electrochemical Sensor for Luteolin Detection. Journal of The Electrochemical Society 2021,168 (8). http://dx.doi.org/10.1149/1945-7111/ac1813.
Supchocksoonthorn, P.; Alvior Sinoy, M. C.; de Luna, M. D. G.; Paoprasert, P., Facile fabrication of 17β-estradiol electrochemical sensor using polyaniline/carbon dot-coated glassy carbon electrode with synergistically enhanced electrochemical stability. Talanta 2021,235. http://dx.doi.org/10.1016/j.talanta.2021.122782.
Zhang, H.; Xing, Z.; Pan, M.; Wang, H.-B.; Liu, Y.-M., Highly Sensitive and Selective Electrochemical Determination of 4-Aminophenol Based on Flower-Like Ag-Au Nanocomposites Modified Glassy Carbon Electrode. Journal of The Electrochemical Society 2020,167 (12). http://dx.doi.org/10.1149/1945-7111/abae91.

There is NO Competing Interest.

Download PDF

Version 1

posted

You are reading this latest preprint version

An electrochemical sensor based on N-doped hollow carbon sphere@ZIF-8 composite for luteolin detection

Status:

Version 1

Abstract

Figures

1. Introduction

2. Experimental Section

2.1 Materials

2.2. Synthesis of hollow carbon spheres

2.3. Synthesis of NC@ZIF-8

2.4. Preparation of NC@ZIF-8/GCE

2.5. Electrochemical analysis

2.6. Material characterization

3. Results and Discussion

3.1. Characterization of the materials

3.2. Brunauer-Emmett analysis of the composite

3.3. Optimization of electrochemical conditions

3.4. Effects of pH and scan rate

3.5. Electrochemical behavior of luteolin on different electrodes

3.6. Establishment of standard curves

3.7. Repeatability and reproducibility testing of the NC@ZIF-8/GCE

3.8. Anti-interference capability of NC@ZIF-8/GCE in luteolin detection

3.9. Detection of actual samples

4. Conclusion

References

Additional Declarations

Status:

Version 1