Elsevier

Biosensors and Bioelectronics

Volume 150, 15 February 2020, 111869
Biosensors and Bioelectronics

Bimetallic nanoparticles decorated hollow nanoporous carbon framework as nanozyme biosensor for highly sensitive electrochemical sensing of uric acid

https://doi.org/10.1016/j.bios.2019.111869Get rights and content

Highlights

  • Au/Co@HNCF sensor displays ultrahigh sensitivity and prominent selectivity.

  • Wide sensing range of 0.1–25 and 25–2500 μM with LOD of 0.023 μM is obtained.

  • Unique Au/Co NPs decorated hollow nanoporous carbon framework are prepared.

  • Highly active Au/Co NPs and abundant sites result in ultrahigh sensitivity.

  • Ordered nanopores and interface discrimination lead to prominent selectivity.

Abstract

An ultrasensitive electrochemical biosensor was developed to identify the low levels of uric acid (UA) in human serum. The gold/cobalt (Au/Co) bimetallic nanoparticles (NPs) decorated hollow nanoporous carbon framework (Au/Co@HNCF) was synthesized as a nanozyme by pyrolysis of the Au (III)-etching zeolitic imidazolate framework-67 (ZIF-67). The external Au NPs combined with internal Co NPs on the hollow carbon framework exhibited enhanced activity for UA oxidation, thereby generating superior signals. Accordingly, the Au/Co@HNCF biosensor presented ranking performances with a low detection limit of 0.023 μM (S/N = 3), an ultrahigh sensitivity of 48.4 μA μM-1 cm-2, and an extensive response in the linear region of 0.1–25 μM and the logarithmic region of 25–2500 μM. Owing to the ordered nanoporous framework and carbon interfacial features, the Au/Co@HNCF biosensor displayed adequate selectivity for UA sensing over a series of biomolecules. In addition, the Au/Co@HNCF biosensor was employed to quantify UA in human serum samples. The test results were basically consistent with those of a commercial apparatus, and thus demonstrated that the proposed Au/Co@HNCF biosensor was reliable for UA determination in clinical research.

Introduction

Uric acid (UA; 2,6,8-trihydroxypurine), as the ultimate metabolite of purine nucleotides, is released by the kidneys into human fluids (Jain et al., 2019). The regular window of UA in healthy human serum is generally 120–460 μM (Liu et al., 2017a). The excess value of UA is used as a momentous biomarker for many clinical diseases, such as uarthritis, nephrosis, and cardiovascular diseases (Shahamirifard et al., 2018). Recent research suggests that the below normal UA level is an important indicator of neuropapillitis, neurodegenerative diseases, sclerosis, and aplastic anemia (Lu et al., 2019; Nigam and Bush, 2019; Long et al., 2016), thus letting determination of the low UA concentrations in human fluids become a crucial challenge. Electrochemical biosensors have many characteristics, such as high accuracy, easy operation, miniaturized devices, which are regarded as the desired devices for UA monitoring (Sha et al., 2019). Nevertheless, the current electrochemical biosensors are insufficient for determination of UA at a low level. Hence, building an ultrasensitive electrochemical biosensor for UA monitoring is highly imperative.

Nanozymes, the nanomaterials with enzyme-mimetic activity, hold tremendous promise for a variety of applications, such as electrochemical sensors, catalysis, and energy conversion (Huang et al., 2019; Cai et al., 2019; Xu et al., 2018). As the substitutions to biological enzymes, nanozymes have inherent superiorities, such as high activity, strong stability (Wang et al., 2018a). Although the great breakthroughs by taking advantage of some nanozymes have been made in the fabrication of highly efficient electrochemical biosensors (Cai et al., 2019; Xu et al., 2018; Li et al., 2019; Tian et al., 2018), constructing more innovative nanozymes is highly desired. Currently, one of the prevalent problems in designing nanozymes is that the substrate can directly and casually diffuse into active sites, which leads to weak selectivity (Wu et al., 2019).

Nanozyme electrochemical biosensors need to have a highly conductive architecture with discriminative features (Maduraiveeran et al., 2018). Hence, a facile assembly of active sites and suitable architectures is a great challenge to be tackled. Metal-organic frameworks (MOFs) present ordered cavity, high metal ion contents, adjustable chemical properties, and are becoming the prospective precursors to construct porous metal-carbon hybrids (Hu et al., 2015).

For enzymatic electrochemical biosensors, the direct electron transfer (DET) between active sites of enzymes and electrode is mainly explored by adjusting the favorable enzyme orientation on electrically conductive vehicles (Lee et al., 2019; Nguyen et al., 2019). However, enzymatic electrochemical biosensors still have major limitations, such as high cost, poor stability. In this study, we explore the use of ultrafine gold/cobalt (Au/Co) nanoparticles (NPs) decorated hollow nanoporous carbon framework (Au/Co@HNCF) as a nanozyme to fabricate UA electrochemical biosensor. The Au/Co@HNCF is constructed by pyrolysis of the Au (III)-etching zeolitic imidazolate framework-67 (ZIF-67). Considering that recent studies reveal a low UA concentration is interrelated with more variety of diseases, it is vital to build a highly selective UA electrochemical biosensor that has a lower detection limit.

Section snippets

Reagents

Cobalt (II) nitrate hexahydrate, 2-methylimidazole (2-MeIm), uric acid (UA), L-serine (Ser), L-asparagine (Asp), ascorbic acid (AA), urea, glycine (Gly), L-histidine (His), glucose (Glu), dopamine (DA), N-methylpyrrolidinone (NMP), and polyvinylidene fluoride (PVDF) were purchased from J&K Chemical Reagent Company (Beijing, China). HAuCl4 solution (23.5–23.8 wt% Au) was obtained from Aladdin (Shanghai, China).

Synthesis of Au (III)-etching ZIF-67

The synthesis routes of ZIF-67 are presented in the supplementary materials.

Synthesis routes

The two-step synthesis routes for Au/Co@HNCF are presented in Fig. S1. In the first step, the Au (III) ions act as more powerful electron acceptors, thereby producing stronger coordination interactions with 2-MeIm. The etching processes proceed on the surfaces of ZIF-67 tendentiously. Thus, the core-shell architectures are acquired. In the second step, the Au (III)-etching ZIF-67 precursor is pyrolyzed into Au/Co@HNCF. The organic ligand (2-MeIm) acts as the reducing agent and carbon source

Conclusions

In summary, the unique Au/Co@HNCF as a nanozyme has been effectively constructed by pyrolysis of the Au (III)-etching ZIF-67. Benefiting from highly active Au/Co NPs, abundant catalytic sites, and hierarchically ordered porous carbon of Au/Co@HNCF, the fabricated nanozyme electrochemical biosensor for UA determination displays ultrahigh sensitivity and prominent selectivity. Moreover, the Au/Co@HNCF biosensor exhibits a very low detection limit (0.023 μM), which thus could be employed to delve

CRediT authorship contribution statement

Kaidong Wang: Methodology, Conceptualization, Software, Visualization, Validation, Writing - original draft, Writing - review & editing. Can Wu: Methodology, Formal analysis, Writing - review & editing. Feng Wang: Formal analysis, Writing - review & editing. Minghao Liao: Investigation, Formal analysis. Guoqiang Jiang: Supervision, Formal analysis, Writing - review & editing, Funding acquisition, Project administration.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work was supported by the National Natural Science Foundation of China [grant numbers 21576148, 21520102008]. The authors are grateful for the supports from Dr. Qiang Shu in the Department of Rheumatology at Qi Lu Hospital of Shangdong University in China.

References (50)

  • X. Cai et al.

    Biosens. Bioelectron.

    (2019)
  • N. Elahi et al.

    Talanta

    (2018)
  • W. Guan et al.

    Biosens. Bioelectron.

    (2014)
  • S. Jain et al.

    Biosens. Bioelectron.

    (2019)
  • S.F. Kiew et al.

    J. Control. Release

    (2016)
  • S.A. Kumar et al.

    Biosens. Bioelectron.

    (2008)
  • W.C. Lee et al.

    Biosens. Bioelectron.

    (2019)
  • Q. Li et al.

    Sens. Actuators, B

    (2018)
  • W. Li et al.

    Biosens. Bioelectron.

    (2019)
  • Y. Liu et al.

    Biosens. Bioelectron.

    (2017)
  • Q. Long et al.

    Biosens. Bioelectron.

    (2016)
  • G. Maduraiveeran et al.

    Biosens. Bioelectron.

    (2018)
  • B.J. Matsoso et al.

    J. Electroanal. Chem.

    (2019)
  • T.N. Nguyen et al.

    Biosens. Bioelectron.

    (2019)
  • A. Ozcan et al.

    Biosens. Bioelectron.

    (2010)
  • B.B. Prasad et al.

    Electrochim. Acta

    (2017)
  • R. Sha et al.

    Sens. Actuators, B

    (2019)
  • S.A. Shahamirifard et al.

    Biosens. Bioelectron.

    (2018)
  • Y. Si et al.

    Biosens. Bioelectron.

    (2018)
  • L. Tian et al.

    Biosens. Bioelectron.

    (2018)
  • Q. Wang et al.

    Trends Anal. Chem.

    (2018)
  • K. Wang et al.

    Electrochim. Acta

    (2018)
  • C. Wu et al.

    Biosens. Bioelectron.

    (2015)
  • Q. Xu et al.

    Biosens. Bioelectron.

    (2018)
  • L. Yang et al.

    Biosens. Bioelectron.

    (2016)
  • Cited by (94)

    View all citing articles on Scopus
    View full text