Graphene Nanomaterials for Non-Enzymatic Electrochemical Sensors for Glucose: History
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Subjects: Nanoscience & Nanotechnology
Contributor:
Angeliki Brouzgou

The high conductivity of graphene material (or its derivatives) and its very large surface area enhance the direct electron transfer, improving non-enzymatic electrochemical sensors sensitivity and its other characteristics. The offered large pores facilitate analyte transport enabling glucose detection even at very low concentration values. Herein classified the enzymeless graphene-based glucose electrocatalysts’ synthesis methods that have been followed into the last few years into four main categories: (i) direct growth of graphene (or oxides) on metallic substrates, (ii) in-situ growth of metallic nanoparticles into graphene (or oxides) matrix, (iii) laser-induced graphene electrodes and (iv) polymer functionalized graphene (or oxides) electrodes. The increment of the specific surface area and the high degree reduction of the electrode internal resistance were recognized as their common targets.

  • graphene-based nanomaterials
  • synthesis
  • reduced graphene oxide
  • glucose electrooxidation mechanism
  • electrochemical sensor
  • cobalt oxide nanomaterial
  • copper oxide nanomaterial
  • nickel oxide nanomaterial
  • direct growth
  • in-situ growth
  • laser-induced
  • polymer functi

1. Direct Growth (or Deposition) of Graphene (or Its Oxides) onto Metallic Substrates

Graphene is usually used independently serving as support to metallic nanoparticles. However, recently in the pursuit of more stable electrochemical glucose sensors, direct growth of graphene nanosheets onto conducting substrates is suggested. The higher advantage of this synthesis method is the omission of the placement step of the graphene-based nanoelectrode onto the electrode’s substrate. In such a way there is not any risk of destroying graphene’s structure, thus the cost lowers and this is a timesaving procedure [1]. Furthermore, the direct growth of graphene leads to an induced-defect 3D structure that minimizes the internal resistances, therefore increases sensor’s response. The created defects are desirable for achieving higher mass transport of the analyte and of the charge, which is required according to our analysis of glucose electrooxidation reaction (GER) mechanism.
Currently, according to our literature research, the CVD synthesis is suggested as the most appropriate method for the graphene direct growth onto metallic substrates [2][3][4]; due to its reproducibility and the high-quality graphene-based electrodes that gives. Following a CVD synthesis route single or multilayer graphene with higher surface area can be produced. Moreover, by varying the experimental conditions the produced graphene layer can be grown onto various substrates giving a layer with a great uniform thickness.
Recently, Wang et al. [2] following the CVD method, they initially grown a graphene layer onto a Cu substrate and then via the electrochemical deposition technique they placed Cu nanoparticles (Figure 1A). The as-resulted electrode was directly used for glucose sensing. They reported a wide linear range of 0.02–2.3 mM, a low detection limit (1.39 μM, S/N = 3), good sensitivity (379.31 μAmM−1cm−2), excellent selectivity and quick response (<5 s). The good sensitivity and stability were attributed to the full coverage of the bilayer graphene from the electrodeposited monolayer of the Cu nanoparticles (Figure 1A). The uniformly dispersion of Cu nanoparticles onto graphene film highly increased the electrodes conductivity. Additionally, the growth of thin graphene layer onto the metallic substrate increased the electron transfer rate between the platform and the catalyst, which is necessary for the quick response of a sensor.
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Figure 1. (A) CuNPs-graphene/Cu bioelectrode fabrication steps and its amperometric response to glucose injection [2]; (B) Synthesis procedure of Cu/Ni-EG/pNi, and the respective amperometric response to glucose injection [5]. (C) TEM images and amperometric response of Ag vertically deposited onto 3D nickel foam graphene and its amperometric response to glucose injection [6]; (D) Synthesis procedure of the CuFe-O/graphene onto nickel foam substrate and its amperometric response to glucose injection [7] and (E) Ni2+ and Co co-reduction onto ITO for the Ni/reduced graphene oxide (rGO)/indium tin oxide (ITO) synthesis and its amperometric response to glucose injection [8].

2. In-Situ Growth of Metallic Nanoparticles into Graphene Nanosheets

The use of graphene material as support enhanced the electrocatalytic activity, of the non-precious metals, receiving a lot of attention for glucose sensing [9][10][11]. However, the uniform dispersion of them onto graphene support, without increasing the electrode’s internal resistance and at the same time acquiring a high catalytic performance, remains a challenge. According to many research groups [12][13][14][15][16][17][18][19][20], an in-situ growth of the metallic nanoparticles inside graphene (or its derivatives) matrix, ensures homogeneous distribution of the nanoparticles and enrichment of the electron transport efficiency. Therefore, the formation of an inside nanostructured matrix with graphene (metal-graphene matrix composites), enhances significantly the electrocatalytic activity towards GER.
One of the most common approaches that is adopted when in-situ fabrication synthesis route is followed, is the application of metallic organic frameworks (MOFs) to the role of the precursor. The MOFs are being formed by the combination of inorganic element (metal element) being surrounded by organic linkers. Specifically, they own a cage-like structure which imparts its crystalline porous structure and an extremely huge internal surface area. Those special characteristics along with their functionable structures, chemical tunability and high compatibility, have make MOFs very attractive materials for a variety of applications [21].
A characteristic example of in-situ growth of 2D MOF onto electrochemical EG surface synthesis method is depicted in Figure 2B [16]. Aiming at developing a high sensitive and stable NiCo-MOF-EG electrode for glucose sensing, Liu et al. [16] followed an in-situ strategy. The MOF nucleation happened preferentially giving very thin nanosheets, as it is shown in Figure 2B, via an easy and fast procedure. The special 2D MOF interconnected porous structure offered a very high specific surface area which facilitated the electrons transfer via metal ion to glucose molecule.
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Figure 2. (A) In-Situ synthesis procedure of Ni2P/graphene and the respective amperometric response to glucose injection [15]; (B) In-Situ synthesis process of a NiCo-MOF-exfoliated graphene electrocatalyst and the respective amperometric response to glucose injection [16]; (C) In-Situ synthesis of graphene@ZIF-67 heterostructure and the respective amperometric response after the glucose injection [17]; (D) In-Situ growth of MOF into physically exfoliated graphene, functionalized the used MOF (ZIF-67) using phytic acid [22] and (E) In-Situ synthesis Ni@C@rGO nanosheets and the resulting amperometric response to glucose detection [23].

3. Laser-Induced Graphene-Based Electrode Synthesis and Functionalization

Laser induced method for graphene synthesis and functionalization is very promising [24]. Using laser tools, the synthesis and functionalization processes are accurately controllable, cost much less than other methods that use chemical agents, also allow the direct growth and functionalization of graphene onto the desired substrate. Moreover, laser methods have great reproducibility since the synthesis process is controlled by the laser operational characteristics, such as wavelength, energy density, etc, and not by chemicals. One way that has been followed by research groups [25] to overcome this challenge is the creation of surface (or structural) defects using more controllable techniques, such as with the use of laser.
It has been found [26] that under the appropriate functional conditions, the laser-engraved defects can be in balance with electrical conductivity. Thus, the created channels and pathways make much easier the charge and ions transport leading to faster response and higher sensitivity of a sensor [27]. Another important advantage of the laser induced graphene electrodes, is the on-site construction of them onto flexible substrates/platforms; in combination with the fact that the raw materials are of lower cost without requiring any post-treatment steps, it seems to gain significant ground as a synthesis strategy. Following this synthesis method the degree of functionalization and the functional groups (-OH, -COOH and others) that are created depend on the operational characteristics of laser, such as wavelength, energy density, etc., [24].
Characteristically, recently, Zhang et al. [28] constructed a 3D porous LIG (Laser induced graphene, with flake shape) electrode deposited onto a flexible substrate for glucose detection, having PI as polymeric substrate and using the produced gas through carbonization process (Figure 3A). Then, Cu nanoparticles were deposited onto LIG by a substrate-assisted electroless deposition process [29]. The resulting graphene nanosheets owned crumples and curves along with small holes, while a lot of graphene edges were present at the laser induced substrate. The graphene ‘defects’ were the channels for the electrons (being provided by the metal) delivery via the metal-carbon ‘bond’ and so the key for glucose electrooxidation reaction evolution. The sensitivity of the Cu-LIG nanoelectrode was estimated 495 μAmM−1cm−2 and the detection limit, 0.39 μM (Figure 3A).
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Figure 3. (A) Cu NPs-LIG synthesis procedure and the respective amperometric response to glucose injection [28]; (B) Direct laser engraved graphene (DLEG) decorated with pulse deposited copper nanocubes and the respective amperometric response to glucose injection [30] (Taping Kapton tape on a thin sheet of PVC (a). Direct laser reduction of the Kapton tape to graphene forming sensor electrodes (b,c). A DREG 3-electrode platform, prepared for further modification (d).) and (C) LIG assisted encapsulation of Co3O4 nanoparticles synthesis method and the respective amperometric response to glucose injection [31].

4. Polymer Functionalized Graphene-Based Electrodes

Graphene functionalization is a strategy that aims at its surface modification for altering graphene’s chemical and physical properties, mainly reducing the cohesive forces that are deployed between the sheets [26]. This is separated into two main categories, non-covalent and covalent functionalization [27]; meaning that in the first case covalent bonds are created, while in the second one the bonds are related to Van der Waals forces.
Graphene as material displays aggregations through Van der Waal interactions, and when defects and functionalities (such as oxygen groups) are in excess, its conductivity and consequently electrocatalytic activity of the graphene-based catalyst, are negatively affected. Therefore, for eliminating such phenomena, organic conducting polymers (with very good electrical conductivity) are used as graphene modifiers and via non-covalent bonding they stabilize graphene’s structure.
Figure 4A shows the structure of a poly-(dimethyl diallyl ammonium chloride (PDDA) functionalized graphene with CuO nanoparticles and the respective amperometric response, to glucose detection. According to catalyst synthesis process the poly-(dimethyl diallyl ammonium chloride (PDDA) polymer, was firstly homogenously dispersed into the graphite oxide solution and then followed the addition of the reducing agent which led to the reduction of graphite oxide to graphene. Its high sensitivity (4982.2 μAmM−1cm−2) and the low detection limit (0.20 μM) were attributed to synergistic effects as well as to the large area that PDDA-graphene offered to metal oxides [32]. Another noteworthy asset of this kind of electrode was its successful testing under human serum without the need of any pretreatment step.
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Figure 4. (A) Poly-(dimethyl diallyl ammonium chloride (PDDA) functionalized graphene decorated with CuO nanoparticles and its respective amperometric response to glucose injection [32]; and (B) PAA covered Ni-rGO synthesis procedure (left) and its respective amperometric response to glucose injection [33].

5. Conclusions

Graphene (or derivatives) structure offer conduction channels improving GER kinetics. More precisely graphene (or its derivatives) significantly reduces electrode’s internal resistance enabling GER via the formation of redox pair peaks, corresponding to the M(II)/M(III) or (M(III)/M(IV)) couple formation. As the resistance is low the charge transfer becomes easier and the metal oxide couples that are responsible for GER progress, are created faster. These faster processes lead to higher stability, sensitivity as well as quicker response of glucose electrochemical sensor operation. For faster and continuous metal couples formation and so higher sensitivity four synthesis methods are mainly recognized among literature works: (i) direct growth of graphene (or oxides) on metallic substrates, (ii) in-situ growth of metallic nanoparticles into graphene (or oxides) matrix, (iii) laser-induced graphene electrodes and (iv) polymer functionalized graphene (or oxides) electrodes. Comparatively, the direct growth of graphene onto metallic substrates and the laser induced graphene electrodes synthesis methods, are more mature. Those two methods use fewer chemical reagents and present higher reproducibility. Moreover, the electrode that presented the highest sensitivity to glucose detection was prepared via the direct growth of graphene onto metallic substrate.

This entry is adapted from the peer-reviewed paper 10.3390/s22010355

References

  1. Singh, V.K.; Kumar, S.; Pandey, S.K.; Srivastava, S.; Mishra, M.; Gupta, G.; Malhotra, B.; Tiwari, R.; Srivastava, A. Fabrication of sensitive bioelectrode based on atomically thin CVD grown graphene for cancer biomarker detection. Biosens. Bioelectron. 2018, 105, 173–181.
  2. Wang, S.; Zhao, L.; Xu, R.; Ma, Y.; Ma, L. Facile fabrication of biosensors based on Cu nanoparticles modified as-grown CVD graphene for non-enzymatic glucose sensing. J. Electroanal. Chem. 2019, 853, 113527.
  3. Soganci, T.; Ayranci, R.; Harputlu, E.; Ocakoglu, K.; Acet, M.; Farle, M.; Unlu, C.G.; Ak, M. An effective non-enzymatic biosensor platform based on copper nanoparticles decorated by sputtering on CVD graphene. Sens. Actuators B Chem. 2018, 273, 1501–1507.
  4. Jiang, J.; Zhang, P.; Liu, Y.; Luo, H. A novel non-enzymatic glucose sensor based on a Cu-nanoparticle-modified graphene edge nanoelectrode. Anal. Methods-R. Soc. Chem. 2017, 9, 2205–2210.
  5. Ren, Z.; Mao, H.; Luo, H.; Liu, Y. Glucose sensor based on porous Ni by using a graphene bottom layer combined with a Ni middle layer. Carbon 2019, 149, 609–617.
  6. Usman, M.; Pan, L.; Farid, A.; Riaz, S.; Khan, A.S.; Peng, Z.Y.; Khan, M.A. Ultra-fast and highly sensitive enzyme-free glucose sensor based on 3D vertically aligned silver nanoplates on nickel foam-graphene substrate. J. Electroanal. Chem. 2019, 848, 113342.
  7. Jeong, H.; Kwac, L.K.; Hong, C.G.; Kim, H.G. Direct growth of flower like-structured CuFe oxide on graphene supported nickel foam as an effective sensor for glucose determination. Mater. Sci. Eng. C 2021, 118, 111510.
  8. Kurt Urhan, B.; Demir, Ü.; Öznülüer Özer, T.; Öztürk Doğan, H. Electrochemical fabrication of Ni nanoparticles-decorated electrochemically reduced graphene oxide composite electrode for non-enzymatic glucose detection. Thin Solid Films 2020, 693, 137695.
  9. Brouzgou, A.; Lo Vecchio, C.; Baglio, V.; Aricò, A.S.; Liang, Z.X.; Demin, A.; Tsiakaras, P. Glucose electrooxidation reaction in presence of dopamine and uric acid over ketjenblack carbon supported PdCo electrocatalyst. J. Electroanal. Chem. 2019, 855, 113610.
  10. Brouzgou, A.; Tsiakaras, P. Electrocatalysts for glucose electrooxidation reaction: A review. Top. Catal. 2015, 58, 1311–1327.
  11. Brouzgou, A.; Podias, A.; Tsiakaras, P. PEMFCs and AEMFCs directly fed with ethanol: A current status comparative review. J. Appl. Electrochem. 2013, 43, 119–136.
  12. Jiang, D.; Chu, Z.; Peng, J.; Luo, J.; Mao, Y.; Yang, P.; Jin, W. One-step synthesis of three-dimensional Co(OH)2/rGO nano-flowers as enzyme-mimic sensors for glucose detection. Electrochim. Acta 2018, 270, 147–155.
  13. Zhang, X.; Zhang, Z.; Liao, Q.; Liu, S.; Kang, Z.; Zhang, Y. Nonenzymatic glucose sensor based on in situ reduction of Ni/NiO-graphene nanocomposite. Sensors 2016, 16, 1791.
  14. Yang, H.; Bao, J.; Qi, Y.; Zhao, J.; Hu, Y.; Wu, W.; Wu, X.; Zhong, D.; Huo, D.; Hou, C. A disposable and sensitive non-enzymatic glucose sensor based on 3D graphene/Cu2O modified carbon paper electrode. Anal. Chim. Acta 2020, 1135, 12–19.
  15. Zhang, Y.; Xu, J.; Xia, J.; Zhang, F.; Wang, Z. MOF-Derived Porous Ni2P/Graphene Composites with Enhanced Electrochemical Properties for Sensitive Nonenzymatic Glucose Sensing. ACS Appl. Mater. Interfaces 2018, 10, 39151–39160.
  16. Liu, B.; Wang, X.; Liu, H.; Zhai, Y.; Li, L.; Wen, H. 2D MOF with electrochemical exfoliated graphene for nonenzymatic glucose sensing: Central metal sites and oxidation potentials. Anal. Chim. Acta 2020, 1122, 9–19.
  17. Chen, X.; Liu, D.; Cao, G.; Tang, Y.; Wu, C. In situ synthesis of a sandwich-like ZIF-67 heterostructure for highly sensitive nonenzymatic glucose sensing in human serums. ACS Appl. Mater. Interfaces 2019, 11, 9374–9384.
  18. Farid, M.M.; Goudini, L.; Piri, F.; Zamani, A.; Saadati, F. Molecular imprinting method for fabricating novel glucose sensor: Polyvinyl acetate electrode reinforced by MnO2/CuO loaded on graphene oxide nanoparticles. Food Chem. 2016, 194, 61–67.
  19. Mao, W.; He, H.; Ye, Z.; Huang, J. Three-dimensional graphene foam integrated with Ni(OH)2 nanosheets as a hierarchical structure for non-enzymatic glucose sensing. J. Electroanal. Chem. 2019, 832, 275–283.
  20. Cui, N.; Guo, P.; Yuan, Q.; Ye, C.; Yang, M.; Yang, M.; Chee, K.W.A.; Wang, F.; Fu, L.; Wei, Q.; et al. Single-Step Formation of Ni Nanoparticle-Modified Graphene–Diamond Hybrid Electrodes for Electrochemical Glucose Detection. Sensors 2019, 19, 2979.
  21. Karimi, M.; Mehrabadi, Z.; Farsadrooh, M.; Bafkary, R.; Derikvandi, H.; Hayati, P.; Mohammadi, K. Chapter 4—Metal–organic framework. In Interface Science and Technology; Ghaedi, M., Ed.; Elsevier: London, UK, 2021; Volume 33, pp. 279–387.
  22. Sun, S.; Tang, Y.; Wu, C.; Wan, C. Phytic acid functionalized ZIF-67 decorated graphene nanosheets with remarkably boosted electrochemical sensing performance. Anal. Chim. Acta 2020, 1107, 55–62.
  23. Hao, J.; Li, C.; Wu, C.; Wu, K. In-situ synthesis of carbon-encapsulated Ni nanoparticles decorated graphene nanosheets with high reactivity toward glucose oxidation and sensing. Carbon 2019, 148, 44–51.
  24. Huang, L.; Su, J.; Song, Y.; Ye, R. Laser-Induced Graphene: En Route to Smart Sensing. Nano-Micro Lett. 2020, 12, 157.
  25. Rodriguez, R.D.; Khalelov, A.; Postnikov, P.S.; Lipovka, A.; Dorozhko, E.; Amin, I.; Murastov, G.V.; Chen, J.-J.; Sheng, W.; Trusova, M.E. Beyond graphene oxide: Laser engineering functionalized graphene for flexible electronics. Mater. Horiz. 2020, 7, 1030–1041.
  26. Reghunath, R.; devi, K.; Singh, K.K. Recent advances in graphene based electrochemical glucose sensor. Nano-Struct. Nano-Objects 2021, 26, 100750.
  27. Yang, G.-h.; Bao, D.-d.; Liu, H.; Zhang, D.-q.; Wang, N.; Li, H.-t. Functionalization of Graphene and Applications of the Derivatives. J. Inorg. Organomet. Polym. Mater. 2017, 27, 1129–1141.
  28. Zhang, Y.; Li, N.; Xiang, Y.; Wang, D.; Zhang, P.; Wang, Y.; Lu, S.; Xu, R.; Zhao, J. A flexible non-enzymatic glucose sensor based on copper nanoparticles anchored on laser-induced graphene. Carbon 2020, 156, 506–513.
  29. Qu, L.; Dai, L. Substrate-Enhanced Electroless Deposition of Metal Nanoparticles on Carbon Nanotubes. J. Am. Chem. Soc. 2005, 127, 10806–10807.
  30. Tehrani, F.; Bavarian, B. Facile and scalable disposable sensor based on laser engraved graphene for electrochemical detection of glucose. Sci. Rep. 2016, 6, 27975.
  31. Zhao, J.; Zheng, C.; Gao, J.; Gui, J.; Deng, L.; Wang, Y.; Xu, R. Co3O4 nanoparticles embedded in laser-induced graphene for a flexible and highly sensitive enzyme-free glucose biosensor. Sens. Actuators B Chem. 2021, 347, 130653.
  32. Yang, J.; Lin, Q.; Yin, W.; Jiang, T.; Zhao, D.; Jiang, L. A novel nonenzymatic glucose sensor based on functionalized PDDA-graphene/CuO nanocomposites. Sens. Actuators B Chem. 2017, 253, 1087–1095.
  33. Bairagi, P.K.; Verma, N. Electro-polymerized polyacrylamide nano film grown on a Ni-reduced graphene oxide-polymer composite: A highly selective non-enzymatic electrochemical recognition element for glucose. Sens. Actuators B Chem. 2019, 289, 216–225.
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