Quantification of DNA through a fluorescence biosensor based on click chemistry

Abstract

A simple, sensitive and selective fluorescence biosensor for determination of DNA using CuS particles based on click chemistry is reported. Biotin-modified capture DNA was modified on Streptavidin MagneSphere Paramagnetic Particles (PMPs) and hybridized with target DNA (hepatitis B virus DNA had been chosen as an example), then bound target DNA was hybridized with DNA-CuS particles and formed a sandwich like structure. CuS particles on the sandwich structures can be destroyed by acid to form Cu(II), and Cu(II) can be reduced to Cu(I) by sodium ascorbate, which in turn catalyzes the reaction between a weak-fluorescent 3-azido-7-hydroxycoumarin and propargyl alcohol to form a fluorescent 1,2,3-triazole compound. Using this method, target DNA concentration can be determined by a change in the fluorescence intensity of the system. It is found that the fluorescence increase factor has a direct linear relationship to the logarithm of target DNA concentrations in the range of 0.1 to 100 nM, and the detection limit is 0.04 nM (S/N = 3). The proposed sensor not only allows high sensitivity and good reproducibility, but also has a good selectivity to single-nucleotide mismatches.

Frequency-selective electrokinetic enrichment of biomolecules in physiological media based on electrical double-layer polarization

“…At 5 MHz field (70 V rms /cm plus 1.5 V DC /cm), while the fluorescence intensity of anti-mouse-IgG does not rise above background level, the respective intensity for PSA is enhanced ~7.5-fold. Based on linear rise of fluorescence intensity versus logarithm of biomarker concentration 33,34 , this suggests ~10 3 -fold concentration enrichment in ~30 s, as validated previously 22 . The nDEP dispersion (Fig.…”

Recent trends in click chemistry as a promising technology for virus-related research

“…To quantify viral DNA, biotin-labeled capture DNA was immobilized onto Streptavidin MagneSphere Paramagnetic Particles and hybridized with hepatitis B viral DNA, followed by hybridizing the target DNA with DNA-CuS particles to form a sandwich like structure (Fig. 3c) (Yue et al, 2014). Then, the CuS particles were acidized to form Cu(II) and Fig.…”

“…later reduced to Cu(I) by sodium ascorbate. The resulting Cu(I) catalyzed the formation of a fluorescent 1,2,3-triazole compound between a weakly fluorescent 3-azido-7-hydroxycoumarin and propargyl alcohol (Yue et al, 2014). It was found that there was a direct linear relationship between the fluorescence intensity and the target DNA concentrations in the range of 0.1-100 nM, and the detection limit is 0.04 nM (Yue et al, 2014).…”

“…The resulting Cu(I) catalyzed the formation of a fluorescent 1,2,3-triazole compound between a weakly fluorescent 3-azido-7-hydroxycoumarin and propargyl alcohol (Yue et al, 2014). It was found that there was a direct linear relationship between the fluorescence intensity and the target DNA concentrations in the range of 0.1-100 nM, and the detection limit is 0.04 nM (Yue et al, 2014). Thomson et al reported an amplificationfree HSV assay, in which magnetic nanoparticles were linked with a copolymer of hydroxyl-and azide-terminated oligoethylene glycol methacrylate, followed by the conjugation of the alkyne-labeled HSspecific DNA capture-probes (Thomson and Cooper, 2013;Thomson et al, 2012).…”

“…Moreover, numerous stable triazoles are produced via click reactions, and thus, whether these triazoles are safe for animals or humans as well as the metabolic pathways of triazoles in biological systems need to be further investigated . Furthermore, as proteins or nucleic acids can be easily digested by protease or nuclease, respectively (Picard-Lafond and Morin, 2017;Qi et al, 2017;Thomson and Cooper, 2013;Thomson et al, 2012;Yue et al, 2014), protease degradation needs to be considered during the modification of peptide or protein, while (Antunes et al, 2015). The presence of the target antigen NS1 triggers MNP agglutination and the formation of nanoclusters with rapid kinetics enhanced by external magnetic actuation (Antunes et al, 2015).…”