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Influence of Reaction Time on Silver Nanoparticles-Catalyzed Oxidation of 3,3’,5,5’-Tetramethylbenzidine

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16 August 2023

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17 August 2023

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Abstract
Influence of reaction time on silver nanoparticles-catalyzed oxidation of 3,3’,5,5’-tetramethylbenzidine (TMB) was evaluated via probing the oxidation process by recording the UV-Visible absorbance of the resulting colored products of TMB oxidation by hydrogen peroxide in the presence of silver nanoparticles as peroxides mimics. The time curve of the oxidation process was constructed, revealed that the concentration of the oxidation product was increased by increasing the reaction time and then levled off because the nanozyme active nodes were saturated after a certain reaction time and consequently the steady-state condition can be observed. The maximal activity of the silver nanozymes was achieved after a very short reaction time as short as 3.0 min and after this time, the color intensity of the oxidation products remained constant, revealing saturation of active nodes of nanoparticles with nanozyme-substrate.
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1. Introduction

Nanozymes or nanoparticles with excellent enzyme-like activity are attracted many attention due to their stability and higher efficiency compared to natural enzymes [1,2,3,4,5,6,7]. In fact, Natural enzymes show several disadvantages such as low stability (thermal and narrow pH range) [8]. For overcoming these drawbacks, the enzyme immobilization process has been developed [9,10,11,12,13]. The recent progresses on nanochemistry and material science open a new door for developing high performance nano-supports such as MOFs, catalytic materials, and nanoparticles with enzyme-like activity [14,15,16,17,18,19,20]. Several of the above-mentioned nanoparticles reveal high peroxidase-like activity which can be used instead of enzymes in the reactions. Recently, the nanozymes had been used for different applications for instance, analytical sensing of species, biocatalysis of reactions instead of natural enzymes, water treatment, dye degradation, sensing and detection [21,22,23,24]. Since nanozymes are able to catalyze the oxidation of peroxidase substrates to their corresponding colored products, they have been used for the analytical purposes [1,2,3,4,5,6,7]. Usually 3,3',5,5'-tetramethylbenzidine (TMB) and 3,3'-diaminobenzidine (DAB) substrates have been used as the peroxidase substrates and their corresponding oxidation products were utilized as the analytical probes for sensing aims [1,2,3,4,5,6,7]. Silver nanoparticles are well-known as the nanomaterials with -peroxidase-like materials [25,26,27,28,29,30]. In this contribution, the effect of incubation time on nanozyme-catalyzed oxidation of 3,3’,5,5’-tetramethylbenzidine over silver nanoparticles due to importance of the reaction time on producing the corresponding radicals. The process of the oxidation reaction was probed by recording the absorbance of the colored products using UV-Vis spectrophotometer. Herein, the influence of reaction time on silver nanoparticles-catalyzed oxidation of 3,3’,5,5’-tetramethylbenzidine (TMB) was evaluated via probing the oxidation process by recording the UV-Visible absorbance of the resulting colored products of TMB oxidation by hydrogen peroxide in the presence of silver nanoparticles as peroxides mimics. The results of this work revealed that the concentration of the oxidation product was increased by increasing the reaction time and then levled off because the nanozyme active nodes were saturated after a certain reaction time and consequently the steady-state condition can be observed.

2. Experimental section

2.1. Synthesis of AgNPs

The synthesis was performed based on the process reported by Hormozi Jangi et al [27]. To do this, silver ions were reduced by NaBH4 in the presence of sodium citrate as stabilizer within 3 hours. After this time, the AgNPs were collected and sored at 4 ℃.

2.2. Oxidation reactions

To do the oxidation reactions, the suitable amount of TMB were introduced into the buffer solutions containing silver nanoparticles and hydrogen peroxide with a fixed pH of 7.0 or 4.0, respectively. The reaction was proceeded for about 5.0 min for TMB oxidation. There after the colored products were analyzed by UV-Vis spectrophotometer at 650 nm for TMB.

3. Results and discussion

3.1. Characterization of silver nanozymes

Unmodified silver nanoparticles were synthesized and characterized for their size and morphological properties. In this regard, the TEM image of the as-prepared nanozyme was recorded and the results are shown in Figure 1, as shown in this figure, the as-prepared silver nanoparticles showed uniform morphology with spherical particles. In addition, the as-prepared nanozymes showed a narrow size distribution over 10.3-12.6 nm with an average size of 11.0 nm.

3.2. Time-course studies toward TMB oxidation

To evaluate the peroxidase-like activity of the as-prepared AgNPs, the oxidation of TMB was performed by hydrogen peroxide in the presence of AgNPs as the peroxidase mimics. In this regard, the time course studies were performed by probing the blue-colored product via spectrophotometric detection at 650.0 nm. Afterward, the plot of oxidation of TMB in the presence of AgNPs as a function of time was constructed by plotting the absorbance at 650.0 nm as a function of reaction time. The results are shown in Figure 2A-B. As can be seen from these figure, the AgNPs can catalyze the oxidation of TMB to form a blue-colored product with a maximum absorbance at 650.0 nm. Based on the time-course studies, the oxidation of TMB was quickly proceed by AgNPs and the absorbance at 650 nm was reached to 1.9 after a short reaction time of 3.0 min. After this time, the color intensity of the oxidation products remained constant, revealing saturation of active nodes of nanoparticles with nanozyme-substrate.

4. Conclusions

Influence of reaction time on silver nanoparticles-catalyzed oxidation of 3,3’,5,5’-tetramethylbenzidine (TMB) was evaluated via probing the oxidation process by recording the UV-Visible absorbance of the resulting colored products of TMB oxidation by hydrogen peroxide in the presence of silver nanoparticles as peroxides mimics. The time curve of the oxidation process was constructed, revealed that the concentration of the oxidation product was increased by increasing the reaction time and then levled off because the nanozyme active nodes were saturated after a certain reaction time and consequently the steady-state condition can be observed. The maximal activity of the silver nanozymes was achieved after a very short reaction time as short as 3.0 min and after this time, the color intensity of the oxidation products remained constant, revealing saturation of active nodes of nanoparticles with nanozyme-substrate.

Acknowledgments

The authors gratefully thank the Hormozi Laboratory of Chemistry and Biochemistry for the support of this work.

Conflicts of Interest

None.

References

  1. Li, W.; Chen, B.; Zhang, H.; Sun, Y.; Wang, J.; Zhang, J.; Fu, Y. BSA-stabilized Pt nanozyme for peroxidase mimetics and its application on colorimetric detection of mercury(II) ions. Biosens. Bioelectron. 2015, 66, 251–258. [Google Scholar] [CrossRef]
  2. Jangi, A.R.H.; Jangi, M.R.H.; Jangi, S.R.H. Detection mechanism and classification of design principles of peroxidase mimic based colorimetric sensors: A brief overview. Chin. J. Chem. Eng. 2020, 28, 1492–1503. [Google Scholar] [CrossRef]
  3. Jangi, S.R.H.; Akhond, M.; Absalan, G. A novel selective and sensitive multinanozyme colorimetric method for glutathione detection by using an indamine polymer. Anal. Chim. Acta 2020, 1127, 1–8. [Google Scholar] [CrossRef]
  4. Jangi, S.R.H.; Akhond, M.; Absalan, G. A field-applicable colorimetric assay for notorious explosive triacetone triperoxide through nanozyme-catalyzed irreversible oxidation of 3, 3′-diaminobenzidine. Microchim. Acta 2020, 187, 1–10. [Google Scholar] [CrossRef]
  5. Huang, Y.; Ren, J.; Qu, X. Nanozymes: Classification, Catalytic Mechanisms, Activity Regulation, and Applications. Chem. Rev. 2019, 119, 4357–4412. [Google Scholar] [CrossRef] [PubMed]
  6. Jangi, S.R.H.; Akhond, M. Synthesis and characterization of a novel metal-organic framework called nanosized electroactive quasi-coral-340 (NEQC-340) and its application for constructing a reusable nanozyme-based sensor for selective and sensitive glutathione quantification. Microchem. J. 2020, 158, 105328. [Google Scholar] [CrossRef]
  7. Akhond, M.; Jangi, S.R.H.; Barzegar, S.; Absalan, G. Introducing a nanozyme-based sensor for selective and sensitive detection of mercury(II) using its inhibiting effect on production of an indamine polymer through a stable n-electron irreversible system. Chem. Pap. 2019, 74, 1321–1330. [Google Scholar] [CrossRef]
  8. Schmid, J.; Heider, D.; Wendel, N.J.; Sperl, N.; Sieber, V. Bacterial Glycosyltransferases: Challenges and Opportunities of a Highly Diverse Enzyme Class Toward Tailoring Natural Products. Front. Microbiol. 2016, 7, 182. [Google Scholar] [CrossRef] [PubMed]
  9. Homaei, Ahmad Abolpour, Reyhaneh Sariri, Fabio Vianello, and Roberto Stevanato. "Enzyme immobilization: an update." Journal of chemical biology 6 (2013): 185-205. [CrossRef]
  10. Jangi, S.R.H.; Akhond, M.; Dehghani, Z. High throughput covalent immobilization process for improvement of shelf-life, operational cycles, relative activity in organic media and enzymatic kinetics of urease and its application for urea removal from water samples. Process. Biochem. 2019, 90, 102–112. [Google Scholar] [CrossRef]
  11. Jangi, S.R.H.; Akhond, M. Introducing a covalent thiol-based protected immobilized acetylcholinesterase with enhanced enzymatic performances for biosynthesis of esters. Process. Biochem. 2022, 120, 138–155. [Google Scholar] [CrossRef]
  12. Garcia-Galan, C.; Berenguer-Murcia, Á.; Fernandez-Lafuente, R.; Rodrigues, R.C. Potential of Different Enzyme Immobilization Strategies to Improve Enzyme Performance. Adv. Synth. Catal. 2011, 353, 2885–2904. [Google Scholar] [CrossRef]
  13. Jangi, S.R.H.; Akhond, M. High throughput urease immobilization onto a new metal-organic framework called nanosized electroactive quasi-coral-340 (NEQC-340) for water treatment and safe blood cleaning. Process. Biochem. 2021, 105, 79–90. [Google Scholar] [CrossRef]
  14. Jangi, S.R.H. Introducing a High Throughput Nanozymatic Method for Eco-Friendly Nanozyme-Mediated Degradation of Methylene Blue in Real Water Media. Sustain. Chem. Eng. 2023, 90–99. [Google Scholar] [CrossRef]
  15. Jangi, S.R.H. Low-temperature destructive hydrodechlorination of long-chain chlorinated paraffins to diesel and gasoline range hydrocarbons over a novel low-cost reusable ZSM-5@Al-MCM nanocatalyst: a new approach toward reuse instead of common mineralization. Chem. Pap. 2023, 1–15. [Google Scholar] [CrossRef]
  16. Hormozi Jangi, S. R. , & Akhond, M. (2021). Ultrasensitive label-free enantioselective quantification of d-/l-leucine enantiomers with a novel detection mechanism using an ultra-small high-quantum yield N-doped CDs prepared by a novel highly fast solvent-free method. Sensors and Actuators B: Chemical, 339, 129901. [CrossRef]
  17. Hormozi Jangi S., R.; Akhond, M. (2020). High throughput green reduction of tris (p-nitrophenyl) amine at ambient temperature over homogenous AgNPs as H-transfer catalyst. Journal of Chemical Sciences, 132, 1-8. [CrossRef]
  18. Jangi, S.R.H.; Gholamhosseinzadeh, E. Developing an ultra-reproducible and ultrasensitive label-free nanoassay for L-methionine quantification in biological samples toward application in homocystinuria diagnosis. Chem. Pap. 2023, 1–13. [Google Scholar] [CrossRef]
  19. Dehghani, Z. , Akhond M., Hormozi Jangi S.R., Absalan G. 2024; 1. [Google Scholar] [CrossRef]
  20. Jangi, S.R.H. Synthesis and characterization of magnesium-based metal-organic frameworks and investigating the effect of coordination solvent on their biocompatibility. 2023.
  21. Amany, A. , El-Rab, S. F. G., & Gad, F. (2012). Effect of reducing and protecting agents on size of silver nanoparticles and their anti-bacterial activity. Der Pharma Chemica, 4(1), 53-65.
  22. Jangi, S.R.H. Determining kinetics parameters of bovine serum albumin-protected gold nanozymes toward different substrates. Qeios 2023. [Google Scholar] [CrossRef]
  23. Jangi, S.R.H.; Davoudli, H.K.; Delshad, Y.; Jangi, M.R.H.; Jangi, A.R.H. A novel and reusable multinanozyme system for sensitive and selective quantification of hydrogen peroxide and highly efficient degradation of organic dye. Surfaces Interfaces 2020, 21, 100771. [Google Scholar] [CrossRef]
  24. Ahmadi-Leilakouhi, B.; Jangi, S.R.H.; Khorshidi, A. Introducing a novel photo-induced nanozymatic method for high throughput reusable biodegradation of organic dyes. Chem. Pap. 2022, 77, 1033–1046. [Google Scholar] [CrossRef]
  25. Jangi, S.R.H.; Dehghani, Z. Spectrophotometric quantification of hydrogen peroxide utilizing silver nanozyme. 2023.
  26. Jangi, S.R.H. Effect of daylight and air oxygen on nanozymatic activity of unmodified silver nanoparticles: Shelf-stability. Qeios 2023. [Google Scholar] [CrossRef]
  27. Hormozi Jangi, S. R. , & Dehghani, Z. (2023). Kinetics and biochemical characterization of silver nanozymes and investigating impact of storage conditions on their activity and shelf-life. Chemical Research and Nanomaterials, 1(4), 25-33.
  28. Mishra, S.; Abdal-Hay, A.; Rather, S.U.; Tripathi, R.M.; Shekh, F.A. Recent Advances in Silver nanozymes: Concept, Mechanism, and Applications in Detection. Adv. Mater. Interfaces 2022, 9. [Google Scholar] [CrossRef]
  29. Karim, N.; Anderson, S.R.; Singh, S.; Ramanathan, R.; Bansal, V. Nanostructured silver fabric as a free-standing NanoZyme for colorimetric detection of glucose in urine. Biosens. Bioelectron. 2018, 110, 8–15. [Google Scholar] [CrossRef] [PubMed]
  30. Jiang, Z.; Li, H.; Deng, Y.; He, Y. Blue Light-Gated Reversible Silver Nanozyme Reaction Networks that Achieve Life-like Adaptivity. ACS Sustain. Chem. Eng. 2020, 8, 5076–5081. [Google Scholar] [CrossRef]
Figure 1. TEM image of as-prepared silver nanoparticles.
Figure 1. TEM image of as-prepared silver nanoparticles.
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Figure 2. Oxidation of TMB in the presence of silver nanozymes as a function of time, (A) time course radar plot and (B) corresponding histogram.
Figure 2. Oxidation of TMB in the presence of silver nanozymes as a function of time, (A) time course radar plot and (B) corresponding histogram.
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Copyright: This open access article is published under a Creative Commons CC BY 4.0 license, which permit the free download, distribution, and reuse, provided that the author and preprint are cited in any reuse.

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