Triplex‐basierte “molecular beacons” als modulare Sonden zur DNA‐Detektion

Abstract

Einstellbare „Signalfeuer“: Eine Triplexbildung wurde zur Konstruktion einer Haarnadelsonde genutzt, die sich bei Bindung der Ziel‐DNA (rot) öffnet. Der Triplex‐basierte „molecular beacon“ besteht aus einem einzelnen DNA‐Strang (blau), einem Fluorophor/Fluoreszenzlöscher‐Paar (rote, blaue Kreise) und einem stammbildenden Oligomer (schwarz). Der modulare Aufbau ermöglicht den Einbau weiterer Funktionalitäten, z. B. von Löschern, zur Konstruktion von „superquenched beacons“.

Gold‐Nanorod‐Based Sensing of Sequence Specific HIV‐1 Virus DNA by Using Hyper‐Rayleigh Scattering Spectroscopy

“…[8][9][10][11][12][29][30][31][32][33][34] Colloidal gold seeds ( % 1.5 nm diameter) were first prepared by mixing aqueous solutions of hexadecylcetyltri-A C H T U N G T R E N N U N G methylammonium bromide (CTAB, 0.1 m, 4.75 mL) and hydrogen tetrachloroaurateA C H T U N G T R E N N U N G (III) hydrate (0.01 m,.2 mL). An aqueous solution of sodium borohydride (0.01 m, .6 mL) was then added.…”

“…The absorption spectra of rod-shaped gold nanoparticles, known as gold nanorods, exhibits two surface plasmon absorption bands. [8][9][10][11][12] A strong, long-wavelength band in the near-infrared region is due to the longitudinal oscillation of the conduction band electrons, and a weak, short-wavelength band around 520 nm is due to the transverse electronic oscillations. The longitudinal absorption band is very sensitive to the aspect ratio and by increasing the aspect ratio (length divided by width), the longitudinal absorption maximum shifts to longer wavelength with an increase in the absorption intensity.…”

“…Keywords: DNA · gold · human immunodeficiency virus · nanostructures · sensors surface plasmon resonance (LSPR) and ease of bioconjugation and potential noncytotoxicity. [1][2][3][4][5][6][7] Conjugates of gold nanoparticles with oligonucleotides are of great current interest, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] because of the potential use of the programmability of DNA base pairing to organize nanocrystals in space and the multiple ways of providing a signature for the detection of a precise DNA sequence. After a pioneering work by Mirkin et al [28] several groups [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] incl...…”

Fluorescence Detection of Single‐Nucleotide Polymorphisms with a Single, Self‐Complementary, Triple‐Stem DNA Probe

“…For example, enzymatic SNP-detection methods, such as endonuclease digestion, [5,6] primer extension, [7] and ligation assays, [8] are very sensitive and specific even at room temperature, but are complex, multistep techniques that often require separation of the resultant products before the presence of the target sequence can be determined. These limitations have motivated the development of simpler fluorescence-based assays with molecular beacons, [9][10][11] binary probes, [12,13] forced intercalation of thiazole orange (FIT) probes, [14] and base-discriminating fluorescent (BDF) probes. [15] Molecular beacons (MBs) are stem-loop oligonucleotides with self-complementary 5' and 3' ends that bring a fluorophore-quencher pair into close proximity in the absence of a target.…”

Metal‐Ion‐Dependent Folding of a Uranyl‐Specific DNAzyme: Insight into Function from Fluorescence Resonance Energy Transfer Studies

“…[31] FRET has been widely used to detect the ion-induced folding of the hammerhead ribozyme, [19b, 32] hairpin ribozyme, [33] hepatitis delta virus (HDV) ribozyme, [34] Neurospora Varkud satellite (VS) ribozyme, [35] Group II intron ribozyme, [36] Diels–Alderase ribozyme, [30c, 37] and the DNA and RNA Holliday junctions. [38] FRET has also been used in the study of other RNA or DNA constructs, including the duplex, [39] bulged duplex, [40] triplex, [41] guanine quadruplex, [42] and i -motif. [43] Herein, we report FRET studies of metal-ion-dependent folding of the 39E DNAzyme–substrate complex and correlate this folding with the activity.…”