Integrated graphene quantum dot decorated functionalized nanosheet biosensor for mycotoxin detection


Decoration of graphene quantum dots (GQDs) on molybdenum disulfide (MoS2) nanosheets serves as an active electrode material which enhances the electrochemical performance of the analyte detection system. Herein, ionic surfactant cetyltrimethylammonium bromide (CTAB)-exfoliated MoS2 nanosheets decorated with GQD material are used to construct an electrochemical biosensor for aflatoxin B1 (AFB1) detection. An antibody of AFB1 (aAFB1) was immobilized on the electrophoretically deposited MoS2@GQDs film on the indium tin oxide (ITO)-coated glass surface using a crosslinker for the fabrication of the biosensor. The immunosensing study investigated by the electrochemical method revealed a signal response in the range of 0.1 to 3.0 ng/mL AFB1 concentration with a detection limit of 0.09 ng/mL. Also, electrochemical parameters such as diffusion coefficient and heterogeneous electron transfer (HET) were calculated and found to be 1.67 × 10−5 cm2/s and 2 × 10−5 cm/s, respectively. The effective conjugation of MoS2@GQDs that provides abundant exposed edge sites, large surface area, improved electrical conductivity, and electrocatalytic activity has led to an excellent biosensing performance with enhanced electrochemical parameters. Validation of the fabricated immunosensor was performed in a spiked maize sample, and a good percentage of recoveries within an acceptable range were obtained (80.2 to 98.3%).

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  1. 1.

    Moretti A, Logrieco AF, Susca A. Mycotoxins: an underhand food problem. Mycotoxigenic Fungi: Springer; 2017. p. 3–12.

  2. 2.

    Abbas HK, Accinelli C, Shier WT. Biological control of aflatoxin contamination in U.S. crops and the use of bioplastic formulations of Aspergillus flavus biocontrol strains to optimize application strategies. J Agric Food Chem. 2017;65(33):7081–7.

    CAS  PubMed  Google Scholar 

  3. 3.

    Neme K, Mohammed A. Mycotoxin occurrence in grains and the role of postharvest management as a mitigation strategies. A review. Food Control. 2017;78:412–25.

    CAS  Google Scholar 

  4. 4.

    Guo W, Wu L, Fan K, Nie D, He W, Yang J, et al. Reduced graphene oxide-gold nanoparticle nanoframework as a highly selective separation material for aflatoxins. Sci Rep. 2017;7(1):14484.

    PubMed  PubMed Central  Google Scholar 

  5. 5.

    Bhardwaj H, Pandey MK, Rajesh, Sumana G. Electrochemical aflatoxin B1 immunosensor based on the use of graphene quantum dots and gold nanoparticles. Microchim Acta. 2019;186(8):592.

    Google Scholar 

  6. 6.

    Guan Z, Lian C-S, Hu S, Ni S, Li J, Duan W. Tunable structural, electronic, and optical properties of layered two-dimensional C2N and MoS2 van der Waals heterostructure as photovoltaic material. J Phys Chem C. 2017;121(6):3654–60.

    CAS  Google Scholar 

  7. 7.

    Hoshide T, Zheng Y, Hou J, Wang Z, Li Q, Zhao Z, et al. Flexible lithium-ion fiber battery by the regular stacking of two-dimensional titanium oxide nanosheets hybridized with reduced graphene oxide. Nano Lett. 2017;17(6):3543–9.

    CAS  PubMed  Google Scholar 

  8. 8.

    Seh ZW, Fredrickson KD, Anasori B, Kibsgaard J, Strickler AL, Lukatskaya MR, et al. Two-dimensional molybdenum carbide (MXene) as an efficient electrocatalyst for hydrogen evolution. ACS Energy Lett. 2016;1(3):589–94.

    CAS  Google Scholar 

  9. 9.

    Huang K-J, Liu Y-J, Wang H-B, Wang Y-Y, Liu Y-M. Sub-femtomolar DNA detection based on layered molybdenum disulfide/multi-walled carbon nanotube composites, Au nanoparticle and enzyme multiple signal amplification. Biosens Bioelectron. 2014;55:195–202.

    CAS  PubMed  Google Scholar 

  10. 10.

    Koppens FHL, Mueller T, Avouris P, Ferrari AC, Vitiello MS, Polini M. Photodetectors based on graphene, other two-dimensional materials and hybrid systems. Nat Nanotechnol. 2014;9:780.

    CAS  PubMed  Google Scholar 

  11. 11.

    Song Y, Luo Y, Zhu C, Li H, Du D, Lin Y. Recent advances in electrochemical biosensors based on graphene two-dimensional nanomaterials. Biosens Bioelectron. 2016;76:195–212.

    CAS  PubMed  Google Scholar 

  12. 12.

    Chen Y, Fan Z, Zhang Z, Niu W, Li C, Yang N, et al. Two-dimensional metal nanomaterials: synthesis, properties, and applications. Chem Rev. 2018;118(13):6409–55.

    CAS  PubMed  Google Scholar 

  13. 13.

    Su S, Sun H, Cao W, Chao J, Peng H, Zuo X, et al. Dual-target electrochemical biosensing based on DNA structural switching on gold nanoparticle-decorated MoS2 nanosheets. ACS Appl Mater Interfaces. 2016;8(11):6826–33.

    CAS  PubMed  Google Scholar 

  14. 14.

    Huang J, He Y, Jin J, Li Y, Dong Z, Li R. A novel glucose sensor based on MoS2 nanosheet functionalized with Ni nanoparticles. Electrochim Acta. 2014;136:41–6.

    CAS  Google Scholar 

  15. 15.

    Ataca C, Ciraci S. Functionalization of single-layer MoS2 honeycomb structures. J Phys Chem C. 2011;115(27):13303–11.

    CAS  Google Scholar 

  16. 16.

    Vilian AE, Dinesh B, Kang S-M, Krishnan UM, Huh YS, Han Y-K. Recent advances in molybdenum disulfide-based electrode materials for electroanalytical applications. Microchim Acta. 2019;186(3):203.

    Google Scholar 

  17. 17.

    Gupta A, Arunachalam V, Vasudevan S. Water dispersible, positively and negatively charged MoS2 nanosheets: surface chemistry and the role of surfactant binding. J Phys Chem Lett. 2015;6(4):739–44.

    CAS  PubMed  Google Scholar 

  18. 18.

    McAteer D, Gholamvand Z, McEvoy N, Harvey A, O’Malley E, Duesberg GS, et al. Thickness dependence and percolation scaling of hydrogen production rate in MoS2 nanosheet and nanosheet–carbon nanotube composite catalytic electrodes. ACS Nano. 2016;10(1):672–83.

    CAS  PubMed  Google Scholar 

  19. 19.

    Li Z, Ye R, Feng R, Kang Y, Zhu X, Tour JM, et al. Graphene quantum dots doping of MoS2 monolayers. Adv Mater. 2015;27(35):5235–40.

    CAS  PubMed  Google Scholar 

  20. 20.

    Zhang Z, Zhang J, Chen N, Qu L. Graphene quantum dots: an emerging material for energy-related applications and beyond. Energy Environ Sci. 2012;5(10):8869–90.

    CAS  Google Scholar 

  21. 21.

    Yan X, Song Y, Zhu C, Song J, Du D, Su X, et al. Graphene quantum dot–MnO2 nanosheet based optical sensing platform: a sensitive fluorescence “Turn Off–On” nanosensor for glutathione detection and intracellular imaging. ACS Appl Mater Interfaces. 2016;8(34):21990–6.

    CAS  PubMed  Google Scholar 

  22. 22.

    Lukowski MA, Daniel AS, Meng F, Forticaux A, Li L, Jin S. Enhanced hydrogen evolution catalysis from chemically exfoliated metallic MoS2 nanosheets. J Am Chem Soc. 2013;135(28):10274–7.

    CAS  PubMed  Google Scholar 

  23. 23.

    Zhang S-L, Yue H, Liang X, Yang W-C. Liquid-phase Co-exfoliated graphene/MoS2 nanocomposite for methanol gas sensing. J Nanosci Nanotechnol. 2015;15(10):8004–9.

    CAS  PubMed  Google Scholar 

  24. 24.

    Coleman JN, Lotya M, O’Neill A, Bergin SD, King PJ, Khan U, et al. Two-dimensional nanosheets produced by liquid exfoliation of layered materials. Science. 2011;331(6017):568.

    CAS  PubMed  Google Scholar 

  25. 25.

    Bhardwaj H, Singh C, Kotnala R, Sumana G. Graphene quantum dots-based nano-biointerface platform for food toxin detection. Anal Bioanal Chem. 2018;410(28):7313–23.

    CAS  PubMed  Google Scholar 

  26. 26.

    Bhardwaj H, Singh C, Pandey M, Sumana G. Star shaped zinc sulphide quantum dots self-assembled monolayers: preparation and applications in food toxin detection. Sensors Actuators B Chem. 2016;231:624–33.

    CAS  Google Scholar 

  27. 27.

    Bhardwaj H, Sumana G, Marquette CA. A label-free ultrasensitive microfluidic surface plasmon resonance biosensor for aflatoxin B1 detection using nanoparticles integrated gold chip. Food Chem. 2020;307:125530.

    PubMed  Google Scholar 

  28. 28.

    Park JH, Kim Y-P, Kim I-H, Ko S. Rapid detection of aflatoxin B1 by a bifunctional protein crosslinker-based surface plasmon resonance biosensor. Food Control. 2014;36(1):183–90.

    CAS  Google Scholar 

  29. 29.

    Tralamazza SM, Bemvenuti RH, Zorzete P, de Souza GF, Corrêa B. Fungal diversity and natural occurrence of deoxynivalenol and zearalenone in freshly harvested wheat grains from Brazil. Food Chem. 2016;196:445–50.

    CAS  PubMed  Google Scholar 

  30. 30.

    Cole RJ, Cox RH. Handbook of toxic fungal metabolites. Academic Press; 1981.

  31. 31.

    Zhao XS, Kong WJ, Wang S, Wei JH, Yang MH. Simultaneous analysis of multiple mycotoxins in Alpinia oxyphylla by UPLC-MS/MS. World Mycotoxin J. 2017;10(1):41–51.

    CAS  Google Scholar 

  32. 32.

    Wang D, Song L, Zhou K, Yu X, Hu Y, Wang J. Anomalous nano-barrier effects of ultrathin molybdenum disulfide nanosheets for improving the flame retardance of polymer nanocomposites. J Mater Chem A. 2015;3(27):14307–17.

    CAS  Google Scholar 

  33. 33.

    Mukherjee S, Maiti R, Midya A, Das S, Ray SK. Tunable direct bandgap optical transitions in MoS2 nanocrystals for photonic devices. ACS Photonics. 2015;2(6):760–8.

    CAS  Google Scholar 

  34. 34.

    Li Y, Wang J, Tian X, Ma L, Dai C, Yang C, et al. Carbon doped molybdenum disulfide nanosheets stabilized on graphene for the hydrogen evolution reaction with high electrocatalytic ability. Nanoscale. 2016;8(3):1676–83.

    CAS  PubMed  Google Scholar 

  35. 35.

    Zhou K, Liu J, Zeng W, Hu Y, Gui Z. In situ synthesis, morphology, and fundamental properties of polymer/MoS2 nanocomposites. Compos Sci Technol. 2015;107:120–8.

    CAS  Google Scholar 

  36. 36.

    Wang C, Jin J, Sun Y, Yao J, Zhao G, Liu Y. In-situ synthesis and ultrasound enhanced adsorption properties of MoS2/graphene quantum dot nanocomposite. Chem Eng J. 2017;327:774–82.

    CAS  Google Scholar 

  37. 37.

    Ali MA, Kamil Reza K, Srivastava S, Agrawal VV, John R, Malhotra BD. Lipid–lipid interactions in aminated reduced graphene oxide interface for biosensing application. Langmuir. 2014;30(14):4192–201.

    CAS  PubMed  Google Scholar 

  38. 38.

    Yan Y, Ge X, Liu Z, Wang J-Y, Lee J-M, Wang X. Facile synthesis of low crystalline MoS 2 nanosheet-coated CNTs for enhanced hydrogen evolution reaction. Nanoscale. 2013;5(17):7768–71.

    CAS  PubMed  Google Scholar 

  39. 39.

    Liu Y-M, Zhou M, Liu Y-Y, Huang K-J, Cao J-T, Zhang J-J, et al. A novel sandwich electrochemiluminescence aptasensor based on molybdenum disulfide nanosheet–graphene composites and Au nanoparticles for signal amplification. Anal Methods. 2014;6(12):4152–7.

    CAS  Google Scholar 

  40. 40.

    Hu SW, Yang LW, Tian Y, Wei XL, Ding JW, Zhong JX, et al. Non-covalent doping of graphitic carbon nitride with ultrathin graphene oxide and molybdenum disulfide nanosheets: an effective binary heterojunction photocatalyst under visible light irradiation. J Colloid Interface Sci. 2014;431:42–9.

    CAS  PubMed  Google Scholar 

  41. 41.

    Ohno R, Ohnuki H, Wang H, Yokoyama T, Endo H, Tsuya D, et al. Electrochemical impedance spectroscopy biosensor with interdigitated electrode for detection of human immunoglobulin A. Biosens Bioelectron. 2013;40(1):422–6.

    CAS  PubMed  Google Scholar 

  42. 42.

    Veth C, Dragicevic D, Merten C. Thermal characterizations of a large-format lithium ion cell focused on high current discharges. J Power Sources. 2014;267:760–9.

    CAS  Google Scholar 

  43. 43.

    Guo T, Wang L, Sun S, Wang Y, Chen X, Zhang K, et al. Layered MoS2@ graphene functionalized with nitrogen-doped graphene quantum dots as an enhanced electrochemical hydrogen evolution catalyst. Chin Chem Lett. 2019;30(6):1253–60.

    CAS  Google Scholar 

  44. 44.

    Guo B, Yu K, Li H, Qi R, Zhang Y, Song H, et al. Coral-shaped MoS2 decorated with graphene quantum dots performing as a highly active electrocatalyst for hydrogen evolution reaction. ACS Appl Mater Interfaces. 2017;9(4):3653–60.

    CAS  PubMed  Google Scholar 

  45. 45.

    Song D, Wang Y, Lu X, Gao Y, Li Y, Gao F. Ag nanoparticles-decorated nitrogen-fluorine co-doped monolayer MoS2 nanosheet for highly sensitive electrochemical sensing of organophosphorus pesticides. Sensors Actuators B Chem. 2018;267:5–13.

    CAS  Google Scholar 

  46. 46.

    Vasilescu I, Eremia SAV, Kusko M, Radoi A, Vasile E, Radu G-L. Molybdenum disulphide and graphene quantum dots as electrode modifiers for laccase biosensor. Biosens Bioelectron. 2016;75:232–7.

    CAS  PubMed  Google Scholar 

  47. 47.

    Balasubramanian P, Balamurugan TST, Chen S-M, Chen T-W, Lin P-H. A novel, efficient electrochemical sensor for the detection of isoniazid based on the B/N doped mesoporous carbon modified electrode. Sensors Actuators B Chem. 2019;283:613–20.

    CAS  Google Scholar 

  48. 48.

    Chandra S, Gäbler C, Schliebe C, Lang H, Bahadur D. Fabrication of a label-free electrochemical immunosensor using a redox active ferrocenyl dendrimer. New J Chem. 2016;40(11):9046–53.

    CAS  Google Scholar 

  49. 49.

    Wang Z, Chen T, Chen W, Chang K, Ma L, Huang G, et al. CTAB-assisted synthesis of single-layer MoS 2–graphene composites as anode materials of Li-ion batteries. J Mater Chem A. 2013;1(6):2202–10.

    Google Scholar 

  50. 50.

    Srivastava S, Ali MA, Umrao S, Parashar UK, Srivastava A, Sumana G, et al. Graphene oxide-based biosensor for food toxin detection. Appl Biochem Biotechnol. 2014;174(3):960–70.

    CAS  PubMed  Google Scholar 

  51. 51.

    Srivastava S, Kumar V, Ali MA, Solanki PR, Srivastava A, Sumana G, et al. Electrophoretically deposited reduced graphene oxide platform for food toxin detection. Nanoscale. 2013;5(7):3043–51.

    CAS  PubMed  Google Scholar 

  52. 52.

    Kalita P, Singh J, Kumar Singh M, Solanki PR, Sumana G, Malhotra B. Ring like self assembled Ni nanoparticles based biosensor for food toxin detection. Appl Phys Lett. 2012;100(9):093702.

    Google Scholar 

  53. 53.

    Yagati A, Chavan S, Baek C, Lee M-H, Min J. Label-free impedance sensing of aflatoxin B1 with polyaniline nanofibers/Au nanoparticle electrode array. Sensors. 2018;18(5):1320.

    Google Scholar 

  54. 54.

    Foguel M, Furlan Giordano G, de Sylos C, Carlos I, Pupim Ferreira A, Benedetti A, et al. A low-cost label-free AFB1 impedimetric immunosensor based on functionalized CD-trodes. Chemosensors. 2016;4(3):17.

    Google Scholar 

  55. 55.

    Li Z, Ye Z, Fu Y, Xiong Y, Li Y. A portable electrochemical immunosensor for rapid detection of trace aflatoxin B 1 in rice. Anal Methods. 2016;8(3):548–53.

    CAS  Google Scholar 

  56. 56.

    Masoomi L, Sadeghi O, Banitaba MH, Shahrjerdi A, Davarani SSH. A non-enzymatic nanomagnetic electro-immunosensor for determination of aflatoxin B1 as a model antigen. Sensors Actuators B Chem. 2013;177:1122–7.

    CAS  Google Scholar 

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We thank Director, CSIR-National Physical Laboratory, New Delhi, India, for providing facilities. We sincerely thank Prof. B.D. Malhotra and Dr. R.K. Kotnala for interesting discussions. H.B. thanks Dr. Chandan Singh, Dr. Shipra Solanki, and Dr. Razi Ahmad for suggestions.

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Correspondence to Gajjala Sumana.

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Bhardwaj, H., Marquette, C.A., Dutta, P. et al. Integrated graphene quantum dot decorated functionalized nanosheet biosensor for mycotoxin detection. Anal Bioanal Chem 412, 7029–7041 (2020).

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  • Molybdenum disulfide
  • Graphene quantum dots
  • Electrochemical impedance spectroscopy
  • Immunosensor
  • Aflatoxin B1