Quantum dot-to-dye-based fluorescent ratiometric immunoassay for GFAP: a biomarker for ischaemic stroke and glioblastoma multiforme.

in The Analyst by Susan Varghese, Anju S Madanan, Merin K Abraham, Ali Ibrahim Shkhair, Geneva Indongo, Greeshma Rajeevan, B K Arathy, Sony George

TLDR

  • A new immunoassay probe for detecting glial fibrillary acidic protein (GFAP) in patients with ischaemic stroke and glioblastoma multiforme has been developed.
  • The probe offers a cost-effective and sensitive detection method with potential applications in clinical settings.
  • Future studies will focus on validating the probe's performance and exploring its applications in the diagnosis of other neurological disorders.

Abstract

Ischaemic stroke and glioma, as leading causes of mortality and long-term disability, pose critical challenges to healthcare systems, necessitating innovative approaches to enable early and cost-effective diagnosis for timely intervention. Glial fibrillary acidic protein (GFAP), an astrocyte-produced protein, is highly responsive to both ischaemic stroke and glioblastoma multiforme, with its levels correlating to the extent of brain damage. In this study, we present the development of an immunoassay probe for the ratiometric fluorescent detection of glial fibrillary acidic protein (GFAP), employing a monoclonal GFAP antibody-conjugated silicon quantum dots (Ab@SiQDs) and rhodamine B dye (RhB)-based immunoprobe. The developed probe exhibited a fluorescence emission shift from 580 nm to 530 nm in response to GFAP, demonstrating a linear detection range from 31.15 pg mLto 243 pg mL, with a limit of detection of 0.7 pg mL. Additionally, the immunoprobe showed high selectivity for GFAP, effectively discriminating it from other potential interfering biomolecules and ions. The probe was also capable of detecting GFAP in spiked serum samples, achieving a recovery rate ranging from 83% to 111%. Notably, a cost-effective paper strip assay was developed, offering significant potential for the visual detection of GFAP under ultraviolet illumination.

Overview

  • The study aimed to develop an immunoassay probe for the ratiometric fluorescent detection of glial fibrillary acidic protein (GFAP) in response to ischaemic stroke and glioblastoma multiforme.
  • The probe consists of a monoclonal GFAP antibody-conjugated silicon quantum dots (Ab@SiQDs) and rhodamine B dye (RhB)-based immunoprobe.
  • The primary objective is to enable early and cost-effective diagnosis for timely intervention in patients with ischaemic stroke and glioblastoma multiforme.

Comparative Analysis & Findings

  • The developed probe exhibited a fluorescence emission shift from 580 nm to 530 nm in response to GFAP.
  • The probe demonstrated a linear detection range from 31.15 pg/mL to 243 pg/mL, with a limit of detection of 0.7 pg/mL.
  • The immunoprobe showed high selectivity for GFAP, effectively discriminating it from other potential interfering biomolecules and ions.

Implications and Future Directions

  • The probe has the potential to enable early detection and diagnosis of ischaemic stroke and glioblastoma multiforme, allowing for timely intervention.
  • The cost-effective paper strip assay offers significant potential for the visual detection of GFAP under ultraviolet illumination.
  • Future studies should focus on validating the probe's performance in clinical settings and exploring its potential applications in the diagnosis of other neurological disorders.
Read Full Article