Issue 6, 2020

Synergistic effect of a “stellate” mesoporous SiO2@Au nanoprobe and coffee-ring-free hydrophilic–hydrophobic substrate assembly in an ultrasensitive SERS-based immunoassay for a tumor marker

Abstract

In the field of surface-enhanced Raman scattering (SERS)-based immunoassays utilizing a sandwich structure, one of the main barriers to overcome is the development of an immunoprobe and substrate with ultrahigh sensitivity and relatively good reproducibility. In this work, a novel gold (Au)-coated “stellate” mesoporous SiO2 (SMSiO2) hybrid structure was proposed and applied as an immunoprobe. It was noticed that the SMSiO2 matrix with an appropriate coating amount of Au nanoparticles (NPs) demonstrated a much higher SERS intensity than solid SiO2 (SSiO2)@Au NPs with an enhancement ratio of 2.6. Electromagnetic “hot spots” existed around the sharp edges and ultrasmall nanogaps of the multibranched SiO2 matrix were verified to be the main reason responsible for the conspicuous enhancement given by the simulation results. Meanwhile, a hydrophilic–hydrophobic SERS-active immunosubstrate was prepared by linking antibodies onto the hydrophilic Ag-deposited sandpaper assembled with hydrophobic-treated filter paper. Such a novel substrate maintained excellent SERS homogeneity with quite a low relative standard deviation (RSD) of 12.85% arising from the elimination of the coffee-ring effect. The constructed sandwich immunoassay structure using the developed immunoprobe and the substrate was successfully employed in a specific assay for the ferritin (FER) antigen and exhibited an extensive dynamic linear range from 1 × 10−5 to 3 × 10−13 g mL−1 with an ultralow limit of detection (LOD) of 3.16 × 10−14 g mL−1. The simplicity and versatility of this strategy demonstrated its superior sensitivity for tumor markers and it can be expected to have potential practical application in the clinical diagnoses of cancer.

Graphical abstract: Synergistic effect of a “stellate” mesoporous SiO2@Au nanoprobe and coffee-ring-free hydrophilic–hydrophobic substrate assembly in an ultrasensitive SERS-based immunoassay for a tumor marker

Supplementary files

Article information

Article type
Paper
Submitted
15 Oct 2019
Accepted
08 Dec 2019
First published
10 Dec 2019

J. Mater. Chem. C, 2020,8, 2142-2154

Synergistic effect of a “stellate” mesoporous SiO2@Au nanoprobe and coffee-ring-free hydrophilic–hydrophobic substrate assembly in an ultrasensitive SERS-based immunoassay for a tumor marker

Z. Yang, H. Liu, Y. Tian, Y. Chen, Z. Niu, C. Zhou, F. Wang, C. Gu, S. Tang, T. Jiang and J. Zhou, J. Mater. Chem. C, 2020, 8, 2142 DOI: 10.1039/C9TC05646G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements