A novel three-dimensionally structured DNA probe is reported to realize in situ"off-on" imaging of intracellular telomerase activity. The probe consists of a DNA tetrahedron and a hairpin DNA on one of the vertices of the DNA tetrahedron. It is composed of four modified DNA segments: S1-Au nanoparticle (NP) inserting a telomerase strand primer (TSP) and S2-S4, three Cy5 dye modified DNA segments. Fluorescence of Cy5 at three vertices of the DNA tetrahedron is quenched by the Au NP at the other vertex due to the effective fluorescence resonance energy transfer (FRET) ("off" state). When the probe meets telomerase, the hairpin structure changes to rod-like through complementary hybridization with the telomerase-triggered stem elongation product, resulting in a large distance between the Au NP and Cy5 and the recovery of Cy5 fluorescence ("on" state). The molar ratio of 3 : 1 between the reporter (Cy5) and the target related TSP makes the probe show high sensitivity and recovery efficiency of Cy5 in the presence of telomerase extracted from HeLa cells. Given the functional and compact nanostructure, the mechanically stable and noncytotoxic nature of the DNA tetrahedron, this FRET-based probe provides more opportunities for biosensing, molecular imaging and drug delivery.
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http://dx.doi.org/10.1039/c6an00241b | DOI Listing |
ACS Nano
January 2025
State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
Higher-order DNA nanomaterials have emerged as programmable tools for probing biological processes, constructing metamaterials, and manipulating mechanically active nanodevices with the multifunctionality and high-performance attributes. However, their utility is limited by intricate mixtures formed during hierarchical multistage assembly, as standard techniques like gel electrophoresis lack the resolution and applicability needed for precise characterization and enrichment. Thus, it is urgent to develop a sorter that provides high separation resolution, broad scope, and bioactive functionality.
View Article and Find Full Text PDFLangmuir
January 2025
School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
The lateral flow assay is a strip-based analytical method for the portable and convenient detection of analytes of interest. It has the advantages of visual observation, autonomous sample flow, fast coloration time, minimal tedious operation procedures, and reliance on specialized instruments. However, the rough surface of the nitrocellulose membrane renders it difficult for the immobilized nucleic acids to remain in an ordered arrangement, and the immobilized nucleic acids are also liable to be digested in a complex matrix, inducing limited sensitivity and anti-interference.
View Article and Find Full Text PDFAnal Chem
January 2025
Key Laboratory of Laboratory Medicine, Ministry of Education of China, and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou 325035, China.
An RCA product is a promising scaffold for the construction of DNA nanostructures, but so far, there is no RCA scaffold-based dynamic reconfigurable nanorobot for biological applications. In this contribution, we develop an intracellular stimuli-responsive reconfigurable coiled DNA nanosnake (N-Snake) by using incomplete aptamer-functionalized (A) DNA tetrahedrons (T) to fold a long tandemly repetitive DNA strand synthesized by rolling circle amplification reaction (R) with the help of palindromic fragment (P). A DNA-assembled product, ARTP, including spiked aptamers, can retain the structural integrity even if exposed to fetal bovine serum (FBS) for 24 h and displays substantially enhanced target molecule-dependent cellular internalization efficiency.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
New Cornerstone Science Laboratory, MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350108, People's Republic of China.
Proteolysis-targeting chimeras (PROTACs) are dual-functional molecules composed of a protein of interest (POI) ligand and an E3 ligase ligand connected by a linker, which can recruit POI and E3 ligases simultaneously, thereby inducing the degradation of POI and showing great potential in disease treatment. A challenge in developing PROTACs is the design of linkers and the modification of ligands to establish a multifunctional platform that enhances degradation efficiency and antitumor activity. As a programmable and modifiable nanomaterial, DNA tetrahedron can precisely assemble and selectively recognize molecules and flexibly adjust the distance between molecules, making them ideal linkers.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, People's Republic of China.
CRISPR-Cas-based technology, emerging as a leading platform for molecular assays, has been extensively researched and applied in bioanalysis. However, achieving simultaneous and highly sensitive detection of multiple nucleic acid targets remains a significant challenge for most current CRISPR-Cas systems. Herein, a CRISPR Cas12a based calibratable single particle counting-mediated biosensor was constructed for dual RNAs logic and ultra-sensitive detection in one tube based on DNA Tetrahedron (DTN)-interface supported fluorescent particle probes coupled with a novel synergistic cascaded strategy between CRISPR Cas13a system and strand displacement amplification (SDA).
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