Bimetallic Pt/Pd encapsulated mesoporous-hollow CeO2 nanospheres for signal amplification toward electrochemical peptide-based biosensing for matrix metalloproteinase 2
Graphical abstract
Based on specific target-induced cleavage of peptide, a sensitive electrochemical biosensor for MMP-2 was constructed by using Pt/Pd/mhCeO2NS as nanocarriers and electrocatalysts.
Introduction
Development of simple, rapid, accurate, and sensitive method for the assay of disease-related proteins, especially cancer biomarkers, is of great importance for many aspects of modern clinical and biomedical fields [1]. Currently, immunoassay protocols based on antibody-antigen interaction is a common approach in the quantitative detection of target biomarkers [2], [3], [4], [5]. Nevertheless, there are some fundamental shortcomings to these approaches such as the requirement of costly antibodies, long incubation time and easily denaturing of antibodies with temperature change [6], [7]. Thus, it is necessary to develop new methods for protein assays. Peptides, with simple and defined structure, which was obtained using phage display technique, exhibit tremendous potential to act as the substitute for bioassay due to their advantages, including versatility, reliability, cost effectiveness, resistance to harsh environments [8], [9]. Several biosensors based on target induced cleavage of peptide have been employed to detect some proteases such as matrix metalloproteinases (MMPs) [10], prostate-specific antigen [11], collagenase [12], cathepsin B [13], caspase [14] and thrombin [15].
MMPs, as a class of zinc-dependent endopeptidases, have received extensive attention because their over-expression was observed in many human cancers [16], [17]. Among them, MMP-2 has been recognized as a biomarker of breast cancer, protease cancer and ovarian cancer [18], [19], [20], [21]. Since a specific peptide with the amino acid sequence PLGVR has been identified as a substrate to measure MMP-2, several peptide-based assay platforms have been explored for the determination of MMP-2, such as fluorescence [22], surface plasmon resonance [23], photoluminescence assays [24]. However, electrochemical methods, which possess such distinct merits as high sensitivity, cheapness, and small size, have been rarely used for detection of MMP-2 in clinical samples [25]. Thus, it is meaningful to search for more sensitive and effective electrochemical platform for the detection of MMP-2 based on specific peptide cleavage induced by target.
To improve the sensitivity of the electrochemical method, various nanomaterials with versatile properties have been extensively employed for signal amplification [26]. Particularly, notched mesoporous-hollow ceria nanospheres (mhCeO2NS), with uniform pore distribution, high surface area, and rigid framework, are desirable to be served as supporting materials to immobilize biomolecules [27], even though CeO2 nanoparticles suffer from low electron conductivity [28]. However, this could be greatly improved by forming nanocomposites of CeO2 with bimetallic Pt/PdNPs, which are of unique electronic conductivity and catalytic property [29]. According to previous reports [30], from the chemistry stand point, lanthanide ions such as cerium (CeO2) are hard Lewis acids. And they have high affinity with hard ligands such as phosphate and carboxyl groups. As a result, we attempted in this work to decorate Pt/PdNPs onto the surface of mhCeO2NS by using l-lysine with NH2 and COOH as a bridge and linker [30], resulting in the formation of Pt/Pd/mhCeO2NS due to the strong interaction between NH2 and metal NPs [31], [32]. Then, Pt/Pd/mhCeO2NS were served as nanocarriers to anchor streptavidin (SA) and electroactive Thi to obtain the proposed nanoprobes SA/Thi/Pt/Pd/mhCeO2NS. Meanwhile, a specific peptide labeled with biotin (biotin-GPLGVRGKGGC, P1) was firstly oriented onto the electrode surface electrodeposited with Au. Then the introduction of target MMP-2 resulted in the specific recognition and cleavage of P1 at a certain site between G and V. Through the high affinity of SA to biotin in remained peptides not cleaved by MMP-2, SA/Thi/Pt/Pd/mhCeO2NS could be bound to the resultant electrode surface. So the electrochemical response could be detected due to the presence of Thi. Based on our observations, the developed peptide-based detecting platform for MMP-2 exhibited improved analytical performance, which was originated from the desired conductivity and catalytic activity of Pt/Pd/mhCeO2NS as nanocarriers and signal enhancer, indicating the potential application for other proteases detection.
Section snippets
Reagents and material
Matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-7 (MMP-7) were bought from Sino Biological Inc., (Beijing, China). Ammonium cerium (IV) nitrate ((NH4)2Ce(NO3)6) and l-lysine were from KeLong Bio. Co., Ltd. (Chengdu, China). Glutaraldehyde (GA) was obtained from Beijing Chemical Reagent Co., (Beijing, China). Palladium potassium chloride (K2PdCl4), chloroplatinic acid (H2PtCl6), gold chloride (HAuCl4), streptavidin (SA), bovine serum albumin (BSA), hemoglobin (Hb), l-cysteine (l
Characterizations of prepared nanoparticles
The morphology and size of CeO2 precursor, mhCeO2NS, and Pt/Pd/mhCeO2NS were investigated by SEM. As shown in Fig. 1A , CeO2 precursors have uniform shapes with a diameter of ∼80 nm. After calcination at 300 °C for 2 h, the obtained mhCeO2NS have rough surface and gaps between every nanospheres could be clearly observed. Moreover, the center of every mhCeO2NS was dark and the edge was bright, which were attributed to that the morphology of the prepared mhCeO2NS was a hollow structure at nanoscale (
Conclusion
In this work, a sensitive electrochemical peptide-based biosensor for MMP-2 detection was successfully fabricated based on the target induced peptide cleavage and the employment of mesoporous-hollow CeO2 nanospheres encapsulated with bimetallic Pt/PdNPs (Pt/Pd/mhCeO2NS) as nanocarriers and signal enhancer. Owing to the great catalytic capacity of Pt/Pd/mhCeO2NS, the amplified electrochemical response was successfully achieved, and the analytical performance of the proposed peptide-based
Acknowledgements
This work was financial supported by NNSF of China (21275119) and Fundamental Research Funds for the Central Universities (XDJK2013A008).
Wenju Xu is an associate professor of chemistry in Southwest University, China. She received her Ph.D. degree in analytical chemistry from Southwest University, China in 2009. Her main areas of interest are chemical sensors and electrochemical biosensors.
References (38)
- et al.
All-graphene composite materials for signal amplification toward ultrasensitive electrochemical immunosensing of tumor marker
Biosens. Bioelectron.
(2015) - et al.
A multi-walled carbon nanotubes-poly(l-lysine) modified enantioselective immunosensor for ofloxacin by using multi-enzyme-labeled gold nanoflower as signal enhancer
Biosens. Bioelectron.
(2015) - et al.
Application of SnO2 nanocrystal as novel electrochemiluminescence signal reporter for sensitive immunoassay with nanoporous PtRu alloy enhancement
Sens. Actuators B: Chem.
(2014) - et al.
Electrochemical immunosensor based on hyperbranched structure for carcinoembryonic antigen detection
Biosens. Bioelectron.
(2014) - et al.
Quantitative electrochemical detection of cathepsin B activity in complex tissue lysates using enhanced AC voltammetry at carbon nanofiber nanoelectrode arrays
Biosens. Bioelectron.
(2014) - et al.
Tryptophan-contained peptide-functional nanomaterials as general spectrofluorometric reagents for enzyme
Talanta
(2008) - et al.
Preparation and assembly of collagen–DNA complex on an electrode surface and its application to protein analysis
Electrochim. Acta
(2013) - et al.
A graphene oxide-based FRET sensor for rapid and sensitive detection of matrix metalloproteinase 2 in human serum sample
Biosens. Bioelectron.
(2013) - et al.
Clinical significance of serum MMP-2 and MMP-7 in patients with ovarian cancer
Anal. Biochem.
(2004) - et al.
A graphene oxide platform for energy transfer-based detection of protease activity
Biosens. Bioelectron.
(2011)
A sensitive electrochemical aptasensor based on palladium nanoparticles decorated graphene–molybdenum disulfide flower-like nanocomposites and enzymatic signal amplification
Anal. Chim. Acta
Fabrication and application of amperometric glucose biosensor based on a novel PtPd bimetallic nanoparticle decorated multi-walled carbon nanotube catalyst
Biosens. Bioelectron.
Positive potential operation of a cathodic electrogenerated chemiluminescence immunosensor based on luminol and graphene for cancer biomarker detection
Anal. Chem.
CMC-modified cellulose biointerface for antibody conjugation
Biomacromolecules
Tag-and-modify approach to site-selective protein modification
Acc. Chem. Res.
Nuclec acid and peptide aptamers: fundamentals and bioanalytical aspects
Angew. Chem. Int. Ed.
A general way to assay protein by coupling peptide with signal reporter via supermolecule formation
Anal. Chem.
A graphene oxide–peptide fluorescence sensor tailor-made for simple and sensitive detection of matrix metalloproteinase 2
Chem. Commun.
Electrogenerated chemiluminescence peptide-based biosensor for the determination of prostate-specific antigen based on target induced cleavage of peptide
Anal. Chem.
Cited by (43)
A disposable immunosensor for the detection of salivary MMP-8 as biomarker of periodontitis
2024, BioelectrochemistryOverview on peptide-based electrochemical biosensors
2023, International Journal of Electrochemical ScienceEnhanced sensing performance of Au-decorated TiO<inf>2</inf> nanospheres with hollow structure for formaldehyde detection at room temperature
2022, Sensors and Actuators B: ChemicalPeptide-based nanomaterials: Self-assembly, properties and applications
2022, Bioactive Materials
Wenju Xu is an associate professor of chemistry in Southwest University, China. She received her Ph.D. degree in analytical chemistry from Southwest University, China in 2009. Her main areas of interest are chemical sensors and electrochemical biosensors.
Pei Jing is MS candidate in the College of Chemistry and Chemical Engineering, Southwest University, China. Her main areas of interest are electrochemical biosensors.
Huayu Yi is MS candidate in the College of Chemistry and Chemical Engineering, Southwest University, China. Her main areas of interest are electrochemical biosensors.
Shuyan Xue is MS candidate in the College of Chemistry and Chemical Engineering of Southwest University, China. Her main areas of interest are electrochemical biosensors.
Ruo Yuan is a professor of chemistry in Southwest University, China. He received a Ph.D. degree in analytical chemistry from Hunan University, China in 1994. The main research interests of professor Yuan are chemical sensors and biosensors.
- 1
These authors contributed equally to this work.