Highly sensitive luminol electrochemiluminescence immunosensor based on platinum-gold alloy hybrid functionalized zinc oxide nanocomposites for catalytic amplification

• Published in: Sensors and actuators. B, Chemical Chemical, 2018-11, Vol.273, p.466-472
• Main Authors: Huang, Xiaomei, Deng, Xiang, Qi, Wenjing, Wu, Di
• Format: Article
• Language: English
• Subjects: Amplification; Biocompatibility; Catalysis; Catalytic activity; Electrochemiluminescence; Glucose oxidase; Gold; Gold alloys; Gold base alloys; Graphene; Hydrogen peroxide; Immunosensor; Immunosensors; Luminol; Nanocomposites; Nanoparticles; Platinum; Platinum-gold alloy hybrid functionalized zinc oxide nanocomposites (Pt-Au@ZnONPs); Sensitivity; Substrates; Surface area; Zinc oxide; Zinc oxides
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2018.06.056

A highly sensitive sandwiched luminol electrochemiluminescence (ECL) immunosensor for sensitive detection of alpha-fetoprotein (AFP) was developed based on in situ generation of hydrogen peroxide working with platinum-gold alloy hybrid functionalized zinc oxide nanocomposites (Pt-Au@ZnONPs) as signal amplification. [Display omitted] •The improved surface area and excellent biocompatibility of platinum-gold alloy hybrid functionalized zinc oxide nanocomposites (Pt-Au@ZnONPs) were used for binding the secondary antibody (Ab2) and glucose oxidase (GOD).•Pt-Au@ZnONPs and the loaded GOD amplified luminol ECL signals and promoted the luminal ECL response by efficiently catalyzing glucose to produce hydrogen peroxide (H2O2) in situ as a coreactant of luminol.•Pt-Au@ZnONPs catalyzed H2O2 to generate various reactive oxygen species that accelerated the ECL reaction of luminol, thus enhancing the ECL intensity of luminol and improving the sensitivity of the immunosensor. A highly sensitive sandwiched luminol electrochemiluminescence (ECL) immunosensor has been constructed based on the double catalysis effect and multiamplification strategy of platinum-gold alloy hybrid functionalized zinc oxide nanocomposites (Pt-Au@ZnONPs). First, the improved surface area and excellent biocompatibility of Pt-Au@ZnONPs were used for binding the secondary antibody (Ab2) and glucose oxidase (GOD) to obtain the novel bioconjugate Pt-Au@ZnONPs-GOD-Ab2. Pt-Au@ZnONPs and the loaded GOD amplified luminol ECL signals and promoted the luminol ECL response by efficiently catalyzing glucose to produce hydrogen peroxide (H2O2) in situ as a coreactant of luminol. Then, Pt-Au@ZnONPs catalyzed H2O2 to generate various reactive oxygen species (ROSs) that accelerated the ECL reaction of luminol, thus enhanced the ECL intensity of luminol and improved the sensitivity of the immunosensor. Second, gold nanoparticles decorated reduced graphene sheets (AuNPs@GS) with large specific surface area, good biocompatibility, high conductivity, and high catalytic activity were prepared and used as substrate of the immunosensor to capture the primary antibody (Ab1). Experimental results demonstrated that the proposed ECL immunosensor showed a sensitive response for the detection of α-1-fetoprotein (AFP) from 0.1 pg mL−1 to 200 ng mL−1 with detection limit of 0.03 pg mL−1 (S/N = 3). The as-proposed luminol ECL immunosensor has excellent sensitivity, stability, and specificity, which makes it very promising for cl