A quantum dot microspheres-based highly specific and sensitive three-dimensional microarray for multiplexed detection of inflammatory factors

Nanotechnology. 2021 Sep 6;32(48). doi: 10.1088/1361-6528/ac1bdd.

Abstract

The development trend ofin vitrodiagnostics is to obtain various biological information from a sample at extremely low concentration and volume, which has promoted its progress in accurate and sensitive multiplexed detection. Here, we developed a single color quantum dot (QD) based three-dimensional (3D) structure matrix microarray and conducted the detection of two inflammatory factors (C-reactive protein (CRP) and serum amyloid A (SAA)) by a self-built fluorescence detection system. This strategy increased detection sensitivity by immobilizing the antibody specifically on the 3D substrate because it captured more than about 7 times of 'effective' antibodies compared to the two-dimensional (2D) plane. Compared to the dual QDs-2D fluorescence-linked immunosorbent assay, the limit of detection (LOD) of 3D microarray based on QDs modified with amphiphilic polymers has been further improved to 0.11 ng ml-1for SAA assay and to 0.16 ng ml-1for CRP assay, respectively. By using QD microspheres (SiO2@QDs@SiO2-COOH, containing approximately 200-300 hydrophobic QDs on per SiO2sphere) as fluorescent labels, the LOD for CRP and SAA of 3D microarray reached as high as 15 pg ml-1and 86 pg ml-1, and the sensitivity was further improved by 28-fold and 425-fold, respectively. Because of its excellent performance, this QD microspheres-based 3D microarray has great application potential for highly sensitive and multiplexed quantitative detection of other biomarkers, small molecules, and antibiotic residues in biomedicine and food safety.

Keywords: 3D structure microarray; SiO2@QDs@SiO2-COOH microspheres; aqueous quantum dot; inflammatory factors; multiplexed detection.

MeSH terms

  • Antibodies, Immobilized / chemistry
  • Biomarkers / analysis
  • C-Reactive Protein / analysis
  • Immunoassay
  • Limit of Detection
  • Microarray Analysis / instrumentation*
  • Microspheres*
  • Quantum Dots / chemistry*
  • Serum Amyloid A Protein / analysis
  • Silicon Dioxide / chemistry

Substances

  • Antibodies, Immobilized
  • Biomarkers
  • Serum Amyloid A Protein
  • Silicon Dioxide
  • C-Reactive Protein