Issue 8, 2016

Immunoassay for tumor markers in human serum based on Si nanoparticles and SiC@Ag SERS-active substrate

Abstract

Based on a sandwich structure consisting of nano-Si immune probes and a SiC@Ag SERS-active immune substrate, a kind of ultra-sensitive immunoassay protocol is presented to detect tumor markers in human serum. The nano-Si immune probes were prepared by immobilizing the detecting antibodies onto the surfaces of SiO2-coated Si nanoparticles (NPs) which were modified with 3-(aminopropyl)trimethoxysilane, and the SiC@Ag SERS-active immune substrates were prepared by immobilizing the captured antibodies on Ag film sputtered on SiC sandpaper. To the best of our knowledge, it is the first time that Si NPs are directly used as Raman tags in an immunoassay strategy. And, the SiC@Ag SERS-active substrates exhibit excellent surface enhanced Raman scattering (SERS) performances with an enhancement factor of ∼105, owing to the plasmonic effect of the Ag film on the rough surface of the SiC sandpaper. In our experiments, the sandwich immunoassay structure has been successfully applied to detect prostate specific antigen (PSA), α-fetoprotein (AFP) and carbohydrate antigen 19-9 (CA19-9) in a human serum sample and the limit of detections are as low as 1.79 fg mL−1, 0.46 fg mL−1 and 1.3 × 10−3 U mL−1, respectively. It reveals that the proposed immunoassay protocol has demonstrated a high sensitivity for tumor markers in human serum and a potential practicability in biosensing and clinical diagnostics.

Graphical abstract: Immunoassay for tumor markers in human serum based on Si nanoparticles and SiC@Ag SERS-active substrate

Supplementary files

Article information

Article type
Paper
Submitted
02 ጃንዩ 2016
Accepted
15 ማርች 2016
First published
15 ማርች 2016

Analyst, 2016,141, 2534-2541

Immunoassay for tumor markers in human serum based on Si nanoparticles and SiC@Ag SERS-active substrate

L. Zhou, J. Zhou, Z. Feng, F. Wang, S. Xie and S. Bu, Analyst, 2016, 141, 2534 DOI: 10.1039/C6AN00003G

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