In this study, we demonstrate how palladium@platinum nanoparticles (Pd@Pt NPs) can be used as a nanozyme for the detection of Staphylococcus aureus (S. aureus) on a paper-based analytical device. Pt was doped with Pd to form bimetallic NPs that serve as a peroxidase mimetic, which can enhance the reaction area with a substrate (3, 3', 5, 5'-tetramethylbenzidine, TMB). After material characterization, we show the peroxidase-like activity of the Pd@Pt NPs featured a 13-times higher binding affinity value (K) for TMB compared to horseradish peroxidase, which is currently widely used in immunoassays. By incorporating the Pd@Pt NPs in a paper-based immunoassay, we can detect protein A, the biomarker of S. aureus, within 30 min with a detection limit of 9.56 ng/mL. We have also successfully validated this nanozyme-immobilized paper-based analytical device (nPAD) for the detection of human immunoglobulin G to demonstrate the capability of the Pd@Pt NPs for different target analytes. This highly sensitive, rapid, and portable nPAD design has the potential for personalized medicine and point-of-care testing, which could expand on-site prognoses in resource-limited settings.
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http://dx.doi.org/10.1016/j.bios.2022.114669 | DOI Listing |
Talanta
March 2025
National Key Laboratory of Veterinary Public Health Security, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China; Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, China Agricultural University, Beijing, 100193, China. Electronic address:
The inherent limitations of natural enzymes hinder their stable application under harsh conditions, highlighting the urgent need for a stable alternative signal tracer. Herein, core-shell palladium@platinum (Pd@Pt) nanoparticles (NPs) with mesoporous and dendritic nanostructures were synthesized using a modified ultrasound-assisted chemical reduction method, resulting in a 25 % improvement in relative activity compared to previously reported methods. The yielding nanoparticles exhibited enhanced peroxidase-like activity with specific activity of 54.
View Article and Find Full Text PDFFood Chem
March 2025
Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing 100083, China. Electronic address:
A press-actuated slidable microfluidic colorimetric biosensor was designed for rapid, sensitive and multi-channel detection of Salmonella. The nickel mesh sheet (NMS) modified with capture antibodies was employed for capturing target bacteria, and metal organic frameworks decorated with palladium (Pd) and platinum (Pt) nanoparticles (MIL-88@Pd/Pt NPs) modified with detection antibodies were used for amplifying colorimetric signals. The capture efficiency of the immune NMS reached 83 %, and the detection limit of this colorimetric biosensor was 35 CFU/mL in 20 min.
View Article and Find Full Text PDFACS Nano
November 2024
Centre for X-ray and Nano Science CXNS, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany.
We studied the adsorption of CO on Pd/Pt nanoparticles (NPs) with varying compositions using polarization-dependent Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS) and theoretical calculations (DFT). We prepared PtPd alloy NPs via physical vapor codeposition on α-AlO(0001) supports. Our morphological and structural characterization by scanning electron microscopy and grazing incidence X-ray diffraction revealed well-defined, epitaxial NPs.
View Article and Find Full Text PDFTalanta
June 2024
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China; Department of Chemistry, Sungkyunkwan University, Suwon, 16419, Republic of Korea. Electronic address:
The improvement of electrochemiluminescence (ECL) performance relies on the electron transfer efficiency between luminophore and coreactant. An ultrasensitive ECL micro-reactor with confinement-enhanced performance was prepared by using the covalent organic framework-LZU1-functionalized metal-organic framework (MOF@COF-LZU1) as a platform to assemble enormous N,N-dibutyl-2-hydroxyethylamine (DBAE) and tris(4,4'-dicarboxylic acid-2,2'-bipyridyl) ruthenium(II) [Ru(dcbpy)] into its pore channels. Compared to individual substances of γ-CD-MOF and COF-LZU1, the synergistic effects can conduce to the enhancement of the intensity, durability and sensitivity of the micro-reactor.
View Article and Find Full Text PDFNanoscale
March 2024
Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan.
In this study, we demonstrate that palladium-platinum bimetallic nanoparticles (Pd@Pt NPs) as the nanozyme, combined with a multi-layer paper-based analytical device and DNA hybridization, can successfully detect . This nanozyme has peroxidase-like properties, which can increase the oxidation rate of the substrate. Compared with horseradish peroxidase, which is widely used in traditional detection, the Michaelis constants of Pd@Pt NPs are fourteen and seventeen times lower than those for 3,3',5,5'-tetramethylbenzidine and HO, respectively.
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