Jump to main content
Jump to site search


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

Author affiliations

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

Back to tab navigation

Supplementary files

Article information


Submitted
05 Nov 2019
Accepted
17 Dec 2019
First published
23 Dec 2019

J. Mater. Chem. B, 2020, Advance Article
Article type
Paper

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, Advance Article , DOI: 10.1039/C9TB02481F

Social activity

Search articles by author

Spotlight

Advertisements