Swelling of Serum-Stable DNA Nanoparticles upon Target-Induced Conformational Rearrangement of Sensing Probes for the Signal-On Detection of Cancer-Related Genes

Abstract

Nuclease-resistant assay probes are of significant importance for biochemical analysis and disease diagnosis. In this contribution, a reconfigurable lipidic moiety-attached DNA nanoparticle (LDN) is constructed from a cholesterol-conjugated multifunctional hairpin-type DNA probe (Chol-DP) by hydrophobicity-mediated self-assembly. The LDN holds high serum stability and displays a low false-positive signal even in a complex biological milieu. The hydrophobic cholesterol moiety enables the hydrophobicity-mediated assembly, while hydrophilic DNA sequence serves as a recognition element and a polymerization template. The initiator-activated strand displacement amplification (SDA) reaction can convert the hairpin-shaped probe into rigid double-stranded DNA (dsDNA), causing the conformational rearrangement-based LDN swelling that can be used to reliably and fluorescently signal the cancer-related p53 gene. The size increase and structural reconfiguration are confirmed by dynamic light scattering (DLS) analysis and confocal microscopy imaging, respectively. Target p53 is specifically detected down to 10 pM. The whole assay process involved only several simple mixing steps. Recovery test and blind test further confirm the feasibility of the use of the LDN for the detection of target DNA in a complex biological milieu, indicating a promising nanotool for biomedical applications.

Intelligent Reconfiguration‐Promoted Cellular Internalization of Core–Shell DNA Nanoprobe Equipped with Successive Dual Stimuli‐Responsive Protective Satellites for Amplification Fluorescence Imaging of Tumor Cells

“…If a DNA tetrahedron without palindromic ends was involved, the assembled product, ES‐NC 0 , is irregular in shape and the height obviously increases (15–35 nm) (Figure S12, Supporting Information), which is possible because of the formation of uncontrollable multilayered structure owing to the hydrophobicity‐mediated random assembly. [ 57 ] If more palindromic bases were introduced at the vertexes of a tetrahedron, the DNA nanoclusters aggregate into more irregular assemblies with a width of 300 nm or even larger (see ES‐NC 6 and ES‐NC 8 in Figures S13 and S14, Supporting Information, respectively). Thus, ES‐NC was used in the subsequent experiments.…”

A label-free activatable biosensor for in situ detection of exosomal microRNAs based on DNA-AgNCs and hairpin type nucleic acid probes

“…In addition, hairpin-shaped nucleic acid probes are oen used as tools for detecting specic nucleic acid sequences due to hybrid complementary properties. 20,21 They have the advantages of high sensitivity, strong specicity, and good stability, and are suitable for RNA imaging in live cells. Hence, we envisage that the advantage of hairpin-shaped nucleic acid probes in target miRNA binding-triggered conformational alteration might be ingeniously utilized to switch the uorescence activation of DNA-AgNCs, thus laying a substantial foundation for the development of a label-free and "signal on" sensor for in situ analysis of exosomal miRNA.…”