Efficient detection of single circulating tumor cell in blood using Raman mapping based on Aptamer-SERS bio-probe coupled with micropore membrane filtration

Talanta. 2024 Jan 15:267:125220. doi: 10.1016/j.talanta.2023.125220. Epub 2023 Sep 21.

Abstract

Rapid and accurate detection of rare circulating tumor cells (CTCs) in human blood still remains a challenge. We present a surface enhanced Raman spectroscopy (SERS) method based on aptamer-SERS bio-probe recognition coupled with micropore membrane filtration capture for the detection of CTCs at single cell level. The parylene micropore membrane with optimized micropore size installed on a filtration holder could capture bio-probe labeled CTCs by gravity in less than 10 s, and only with very less white blood cells (WBCs) residual. In order to facilitate the synthesis of the aptamer-SERS bio-probe, ethyl acetate dehydration method was established. The bio-probe can be rapidly synthesized within 2 h by binding SH-aptamer to 4- mercaptobenzoic acid (4-MBA) modified AuNPs with the help of ethyl acetate. The SERS bio-probe with selected specific aptamer could distinguish single human non-small cell lung cancer A549 cells from residual WBCs on membrane efficiently and reliably based on their Raman signal intensity difference at 1075 cm-1. Through the filter membrane coupled with aptamer-SERS bio-probe system, even 20 A549 cells in blood solution simulating CTCs sample can be detected, which the recovery rate and recognition rate are more than 90%. This method is rapid, reliable and cost-effective, which indicates a good prospect in clinical application for CTCs detection.

Keywords: Aptamer; Circulating tumor cells; Micropore membrane; Size-based isolation; Surface enhanced Raman spectroscopy.

MeSH terms

  • Aptamers, Nucleotide* / chemistry
  • Biosensing Techniques* / methods
  • Carcinoma, Non-Small-Cell Lung*
  • Gold / chemistry
  • Humans
  • Lung Neoplasms* / diagnosis
  • Metal Nanoparticles* / chemistry
  • Neoplastic Cells, Circulating*
  • Spectrum Analysis, Raman / methods

Substances

  • ethyl acetate
  • Gold
  • Aptamers, Nucleotide