nanosensor
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In this study, NaYF4:20%Yb, 2%Er upconverting nanoparticles (UCNPs) were synthesized by solvothermal method and characterized by transmission electron microscopy and upconversion fluorescence spectrometry. The results showed that the UCNP particles present good dispersion and uniform spherical shape with a size of 29 ~ 42 nm. Hydroxyl UCNPs were converted to hydrophilic carboxylic acid-functionalized ones by ligand exchange, and the streptavidin was attached on the surface of carboxylic acid-functionalized UCNPs via amide bond. The DNA nanosensors based on UCNPs with DNA probes have been successfully developed. Only the genomic DNA of Nosema bombycis can be specifically detected by the DNA nanosensors when the DNA of Bombyx mori and its pathogens was used as target DNA. When the DNA nanosensors were used to detect the DNA of N. bombycis, a broad emission peak signal appeared at 580 nm. There is linear relationship between the signal intensity and DNA concentration of N. bombycis, I580/I545 (R2 = 0.820) and I545/I654 (R2 = 0.901). The detectable minimum concentration of genomic DNA of N. bombycis was 100 ng/μL while the tested concentrations of N. bombycis genomic DNA were 3000 ng/μL, 1500 ng/μL, 1000 ng/μL, 500 ng/μL, 250 ng/μL, and 100 ng/μL, respectively. The whole detection process for target DNA takes less than 60 min.
DNA nanodevices have been developed as platforms for the manipulation of gene expression, delivery of molecular payloads, and detection of various molecular targets within cells and in other complex biological settings. Despite efforts to translate DNA nanodevices from the test tube (in vitro) to living cells, their intracellular trafficking and functionality remain poorly understood. Herein, quantitative and super-resolution microscopy approaches were employed to track and visualise, with nanometric resolution, the molecular interactions between a synthetic DNA nanosensor and transcription factors in intracellular compartments. Specifically, fluorescence resonance energy transfer microscopy, fluorescence correlation spectroscopy, fluorescence lifetime imaging microscopy and multicolour single-molecule localisation microscopy were employed to probe the specific binding of the DNA nanosensor to the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). We monitored the mobility, subcellular localisation and degradation of the DNA nanosensor inside living prostate cancer PC3 cells. Super-resolution imaging enabled the direct visualisation of the molecular interactions between the synthetic DNA nanosensors and the NF-κB molecules in cells. This study represents a significant advance in the effective detection as well as understanding of the intracellular dynamics of DNA nanosensors in a complex biological milieu.
- MeSH
- DNA vazebné proteiny MeSH
- DNA MeSH
- lidé MeSH
- NF-kappa B * genetika metabolismus MeSH
- rezonanční přenos fluorescenční energie MeSH
- signální transdukce * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
We developed membrane voltage nanosensors that are based on inorganic semiconductor nanoparticles. We provide here a feasibility study for their utilization. We use a rationally designed peptide to functionalize the nanosensors, imparting them with the ability to self-insert into a lipid membrane with a desired orientation. Once inserted, these nanosensors could sense membrane potential via the quantum confined Stark effect, with a single-particle sensitivity. With further improvements, these nanosensors could potentially be used for simultaneous recording of action potentials from multiple neurons in a large field of view over a long duration and for recording electrical signals on the nanoscale, such as across one synapse.
- MeSH
- biosenzitivní techniky metody MeSH
- elektřina * MeSH
- HEK293 buňky MeSH
- kvantové tečky chemie MeSH
- lidé MeSH
- membránové potenciály fyziologie MeSH
- nanotrubičky ultrastruktura MeSH
- povrchové vlastnosti MeSH
- studie proveditelnosti MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Research Support, N.I.H., Extramural MeSH
Development of multifunctional nanoscale sensors working under physiological conditions enables monitoring of intracellular processes that are important for various biological and medical applications. By attaching paramagnetic gadolinium complexes to nanodiamonds (NDs) with nitrogen-vacancy (NV) centres through surface engineering, we developed a hybrid nanoscale sensor that can be adjusted to directly monitor physiological species through a proposed sensing scheme based on NV spin relaxometry. We adopt a single-step method to measure spin relaxation rates enabling time-dependent measurements on changes in pH or redox potential at a submicrometre-length scale in a microfluidic channel that mimics cellular environments. Our experimental data are reproduced by numerical simulations of the NV spin interaction with gadolinium complexes covering the NDs. Considering the versatile engineering options provided by polymer chemistry, the underlying mechanism can be expanded to detect a variety of physiologically relevant species and variables.
- MeSH
- biosenzitivní techniky metody MeSH
- časové faktory MeSH
- koncentrace vodíkových iontů MeSH
- konfokální mikroskopie MeSH
- kvantová teorie MeSH
- nanodiamanty chemie ultrastruktura MeSH
- nanotechnologie metody MeSH
- optické zobrazování metody MeSH
- oxidace-redukce MeSH
- reprodukovatelnost výsledků MeSH
- transmisní elektronová mikroskopie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We show that fluorescent nanodiamonds (FNDs) are among the few types of nanosensors that enable direct optical reading of noncovalent molecular events. The unique sensing mechanism is based on switching between the negatively charged and neutral states of NV centers which is induced by the interaction of the FND surface with charged molecules.
Fluorescence resonance energy transfer (FRET) in combination with quantum dots (QDs) and their superior properties has enabled designing of the new and improved sensors. In this review, the latest novelties in development and application of FRET nanosensors employing QDs are presented. QDs offer several advantages over organic dyes - broad excitation spectra, narrow defined tunable emission peak, longer fluorescence lifetime, resistance to photobleaching and 10-100 times higher molar extinction coefficient. These properties of QDs allow multicolor QDs to be excited from one source by common fluorescent dyes without emission signal overlap and results in brighter probes comparing to conventional fluorophores. Due to these benefits, QD-FRET-based nanosensors gained a wide spread popularity in a variety of scientific areas. These sensors are most frequently applied in the domain of the nucleic acid and enzyme activity detection. Other applications are detection of peptides and low-molecular compounds, environmental pollutants, viruses, microorganisms and their toxins, QD-FRET-based immunoassays, and pH sensors.
- MeSH
- analýza selhání vybavení MeSH
- biosenzitivní techniky přístrojové vybavení MeSH
- biotest přístrojové vybavení MeSH
- design vybavení MeSH
- kvantové tečky * MeSH
- nanotechnologie přístrojové vybavení MeSH
- rezonanční přenos fluorescenční energie přístrojové vybavení MeSH
- sekvenční analýza DNA přístrojové vybavení MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
