title: Microfluidic paper-based multiplex colorimetric immunodevice based on the catalytic effect of Pd/Fe₃O₄@C peroxidase mimetics on multiple chromogenic reactions.
abstract: In this report, a non-toxic method was proposed for the simple synthesis of palladium nanoparticles (Pd)/Fe3O4@C peroxidase mimetics by virtue of in situ growth of Pd nanoparticles on Fe3O4@C magnetic nanoparticles. And a microfluidic paper-based multiplex colorimetric immunodevice (named α-sheet) was developed by site-selectively immobilizing multiple antigens owing to its intrinsic high-efficiency catalytic activity of peroxidase mimetics to multiple chromogenic reactions. The immunosensor platform was prepared by growing a layer of flower-like gold nanoparticles which could entrap the primary antibodies onto paper sensing zones, and the as-prepared Pd/Fe3O4@C peroxidase mimetics was used to label secondary antibodies. In the presence of 3,3',5,5'-tetramethylbenzidine and o-phenylenediamine chromogenic substrates, Pd/Fe3O4@C peroxidase mimetics catalyzed chromogenic reactions and showed different colors with respective intensity. To precisely identify the intensity, a piece of black wax printed chromatographic paper with three observing windows (named β-sheet) was flatted on α-sheet. Under the optimal condition, the proposed multiplex colorimetric immunodevice displayed wide linear ranges from 0.005 to 30 ng mL(-1) with low detection limits of 1.7 pg mL(-1) for carcinoembryonic antigen (CEA) and α-fetoprotein (α-AFP). Meanwhile, the proposed method provided provided a non-toxic, low-cost and promising tool for point-of-care diagnosis.
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Linlin
authors: L
authors: Liang
authors: Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, PR China.
authors: Shenguang
authors: S
authors: Ge
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Li
authors: L
authors: Li
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Fang
authors: F
authors: Liu
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China. Electronic address: ujn.yujh@gmail.com.
authors: Jinghua
authors: J
authors: Yu
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D002384:Catalysis; D003124:Colorimetry / Q000295:instrumentation / Q000379:methods*; D005290:Ferric Compounds / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D058185:Magnetite Nanoparticles / Q000737:chemistry; D046210:Microfluidic Analytical Techniques; D010165:Palladium / Q000737:chemistry*; D010209:Paper; D009195:Peroxidase / Q000378:metabolism*; D019095:Point-of-Care Systems
chemical_list: D014408:Biomarkers, Tumor; D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; C000499:ferric oxide; D010165:Palladium; D009195:Peroxidase
keywords: Chromogenic reactions; Paper-based multiplex colorimetric immunodevice; Pd/Fe(3)O(4)@C peroxidase mimetics; Point-of-care diagnosis