Oropesa-Nuñez R, Zardán Gómez de la Torre T, Stopfel H, Svedlindh P, Strömberg M, Gunnarsson K. Insights into the Formation of DNA-Magnetic Nanoparticle Hybrid Structures: Correlations between Morphological Characterization and Output from Magnetic Biosensor Measurements.
ACS Sens 2020;
5:3510-3519. [PMID:
33141554 PMCID:
PMC7706118 DOI:
10.1021/acssensors.0c01623]
[Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
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Understanding
the binding mechanism between probe-functionalized
magnetic nanoparticles (MNPs) and DNA targets or amplification products
thereof is essential in the optimization of magnetic biosensors for
the detection of DNA. Herein, the molecular interaction forming hybrid
structures upon hybridization between DNA-functionalized magnetic
nanoparticles, exhibiting Brownian relaxation, and rolling circle
amplification products (DNA-coils) is investigated by the use of atomic
force microscopy in a liquid environment and magnetic biosensors measuring
the frequency-dependent magnetic response and the frequency-dependent
modulation of light transmission. This approach reveals the qualitative
and quantitative correlations between the morphological features of
the hybrid structures with their magnetic response. The suppression
of the high-frequency peak in the magnetic response and the appearance
of a new peak at lower frequencies match the formation of larger sized
assemblies upon increasing the concentration of DNA-coils. Furthermore,
an increase of the DNA-coil concentration induces an increase in the
number of MNPs per hybrid structure. This study provides new insights
into the DNA–MNP binding mechanism, and its versatility is
of considerable importance for the mechanistic characterization of
other DNA-nanoparticle biosensor systems.
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