Issue 16, 2020

Biomolecular detection, tracking, and manipulation using a magnetic nanoparticle-quantum dot platform

Abstract

Fluorescent and magnetic materials play a significant role in biosensor technology, enabling sensitive quantification and separations with applications in diagnostics, purification, quality control, and therapeutics. Here, we present a magneto–fluorescent biosensor/separations platform consisting of quantum dots (QDs) and superparamagnetic iron oxide nanoparticles (SPIONs) that are separately encapsulated in amphiphilic block co-polymer micelles conjugated to DNA or protein (i.e., single-stranded (ss) DNA derived from the mRNA of the tumor suppressor protein p53 or avidin protein). Analytes were detected via an aggregation sandwich assay upon binding of at least 1 QD and 1 SPION-containing micelle to result in a fluorescent/magnetic composite. Multiplexed isolation of protein and DNA biomolecules was demonstrated by using QDs of varying emission wavelength; QD fluorescence intensity could be correlated with analyte concentration. Sequential or parallel biomolecule separation was achieved by adding appropriately functionalized SPION-containing micelles and applying user-controlled magnetic fields via patterned magnetic disks and wires. QD fluorescence was used to continuously visualize analyte separation during this process. This QD/SPION platform is simple to use, demonstrates ∼10−16 M sensitivity in analyte detection (comparable to competing QD biosensors based on energy transfer) with specificity against 1 and 2 basepair mismatches in DNA detection, molecular separations capability in solutions of ∼10−10 M, and permits simultaneous or parallel, multiplexed separation of protein and DNA. Thus, this versatile platform enables self-assembly-based rapid, sensitive, and specific detection and separation of biomolecules, simultaneously and with real-time visualization. This technology demonstrates potential for nanoscale assembly, biosensing, and bioseparations.

Graphical abstract: Biomolecular detection, tracking, and manipulation using a magnetic nanoparticle-quantum dot platform

  • This article is part of the themed collection: Biosensors

Supplementary files

Article information

Article type
Paper
Submitted
05 Huk 2019
Accepted
17 N’w 2019
First published
23 N’w 2019

J. Mater. Chem. B, 2020,8, 3534-3541

Author version available

Biomolecular detection, tracking, and manipulation using a magnetic nanoparticle-quantum dot platform

K. D. Mahajan, G. Ruan, G. Vieira, T. Porter, J. J. Chalmers, R. Sooryakumar and J. O. Winter, J. Mater. Chem. B, 2020, 8, 3534 DOI: 10.1039/C9TB02481F

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