Synthesis of Fe₃C@C from Pyrolysis of Fe₃O₄-Lignin Clusters and Its Application for Quick and Sensitive Detection of PrPSc through a Sandwich SPR Detection Assay.

Chenglong Yuan,Weikai Wang,Yanjun Li,Zhichao Lou,Lintian Yang

doi:10.3390/ijms20030741

Chenglong Yuan, Weikai Wang + Show 3 more

Open Access

https://doi.org/10.3390/ijms20030741

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Abstract

The prion protein (PrPSc) has drawn widespread attention due to its pathological potential to cause prion diseases. Herein, we successfully synthesized Fe3C@C by carbonizing Fe3O4-lignin clusters, which were prepared through a facile hydrogen bonding interaction between ≡Fe-OH and hydroxyl groups of lignin. Our in-depth investigation confirmed that the composites were Fe3C@C core/shell particles. We constructed a novel sandwich surface plasmon resonance (SPR) detection assay for sensitive PrPSc detection, utilizing bare gold surface and aptamer-modified Fe3C@C (Fe3C@C-aptamer). Due to the highly specific affinity of Fe3C@C-aptamer towards PrPSc, the sandwich type SPR sensor exhibited excellent analytical performance towards the discrimination and quantitation of PrPSc. A good linear relationship was obtained between the SPR responses and the logarithm of PrPSc concentrations over a range of 0.1–200 ng/mL. The detection sensitivity for PrPSc was improved by ~10 fold compared with the SPR direct detection format. The required detection time was only 20 min. The specificity of the present biosensor was also confirmed by PrPC and other reagents as controls. This proposed approach could also be used to isolate and detect other highly pathogenic biomolecules with similar structural characteristics by altering the corresponding aptamer in the Fe3C@C conjugates.

Highlights

The prion protein has drawn great attention due to its pathological potential to cause prion diseases, which are recognized as highly contagious and scarcely incurable [1]
PrPSc can introduce the transformation of normal PrPC, PrPSc is supposed to be a marker for transmissible spongiform encephalopathy infections and to be a causative agent [5,6]
Numerous traditional methods have been introduced for the detection of PrPSc, such as protein misfolding cyclic amplification [7], ELISA [8], micromechanical resonator arrays [9], fluorescence correlation spectroscopy [10], fluorescence in situ hybridization (FISH) [11], and immune-quantitative real-time PCR assays [12]

Summary

Introduction

The prion protein has drawn great attention due to its pathological potential to cause prion diseases, which are recognized as highly contagious and scarcely incurable [1]. Numerous traditional methods have been introduced for the detection of PrPSc, such as protein misfolding cyclic amplification [7], ELISA [8], micromechanical resonator arrays [9], fluorescence correlation spectroscopy [10], fluorescence in situ hybridization (FISH) [11], and immune-quantitative real-time PCR assays [12] These methods have been proven to be with good sensitivity and some of them are commonly used in practical tests. These methods normally require practiced experimental skills and expensive instruments, and are time- and labor-intensive, making them difficult to be used for the high-throughput detection or routine testing Compared with these methods, surface plasmon resonance (SPR) biosensors are supposed to be commercialized approaches with higher precisions and sensitivities, which have been used in the field of theranostics (therapeutics and diagnostics), pharmaceutics, food safety, environmental monitoring and homeland security [13,14]. It is important for the fabrication of a novel SPR-based detection assay for the detection of PrPSc with ultra-sensitivity and high-specificity

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Conclusion