Robust silica-coated quantum dot–molecular beacon for highly sensitive DNA detection

Wu, Chung Shieh; Oo, Maung Kyaw Khaing; Cupps, Jay M.; Fan, Xudong

doi:10.1016/j.bios.2011.02.049

Cited by 41 publications

(26 citation statements)

References 29 publications

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“…The alloyed TGA-capped CdZnSeS QDs were silanized according to a reported procedure (Wu et al, 2011) with modifications. The amino-silanized QDs were prepared by mixing 10 mL of 3-APTMS with 5 mL of methanol and added to 10 mL of an aqueous alloyed QD solution at room temperature with vigorous stirring.…”

Section: Silica Encapsulation Of Alloyed Cdznses Qdsmentioning

confidence: 99%

An ultrasensitive SiO2-encapsulated alloyed CdZnSeS quantum dot-molecular beacon nanobiosensor for norovirus

Adegoke

Seo

Kato

et al. 2016

Biosensors and Bioelectronics

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Ultrasensitive, rapid and selective diagnostic probes are urgently needed to overcome the limitations of traditional probes for norovirus (NV). Here, we report the detection of NV genogroup II via nucleic acid hybridization technology using a quantum dot (QD)-conjugated molecular beacon (MB) probe. To boost the sensitivity of the MB assay system, an ultrasensitive QD fluorophore with unique optical properties was synthesized, characterized and exploited as a fluorescence signal generator. Alloyed thioglycolic (TGA)-capped CdZnSeS QDs with a high photoluminescence (PL) quantum yield (QY) value of 92% were synthesized, and a modified silanization method was employed to encapsulate the thiol-capped QDs in a silica layer. The resulting highly luminescent alloyed SiO2-coated CdZnSeS QDs had a remarkable PL QY value of 98%. Transmission electron microscopy and dynamic light scattering confirmed the monodispersity of the alloyed nanocrystals, and zeta potential analysis confirmed their colloidal stability. Powder X-ray diffraction and PL lifetime measurements confirmed the surface modification of the QDs. The alloyed TGA-capped and SiO2-coated CdZnSeS QD-conjugated MB bioprobes detected extremely low concentrations of NV RNA. Ultrasensitive detection of low concentrations of NV RNA with a limit of detection (LOD) of 8.2copies/mL in human serum and a LOD of 9.3 copies/mL in buffer was achieved using the SiO2-coated CdZnSeS QD-MB probes, an increase in sensitivity of 3-fold compared with the detection limit for NV RNA using TGA-capped CdZnSeS QD-MBs. The additional merits of our detection system are rapidity, specificity and improved sensitivity over conventional molecular test probes.

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Section: Silica Encapsulation Of Alloyed Cdznses Qdsmentioning

confidence: 99%

An ultrasensitive SiO2-encapsulated alloyed CdZnSeS quantum dot-molecular beacon nanobiosensor for norovirus

Adegoke

Seo

Kato

et al. 2016

Biosensors and Bioelectronics

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“…Functionalization using alkane thiols with different end groups is well established for modification of metal surfaces (Ulman 1996). Hence, β-mercaptoethanol SAM can be used to obtain a coverage of hydroxyl functionalities on gold, facilitating silanization with TMS-PMA, which is analogous to silanization of β-mercaptoethanol modified quantum dots using amino functionalized silane (Wu et al 2011). Modification tests of gold surfaces followed by hydrogel polymerization yielded a strongly bonded hydrogel similarly as for the modified silicon nitride surfaces.…”

Section: Modification and Characterization Of Gold Electrode Microchipsmentioning

confidence: 94%

A reusable device for electrochemical applications of hydrogel supported black lipid membranes

Mech-Dorosz

Heiskanen

Bäckström

et al. 2015

Biomed Microdevices

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Black lipid membranes (BLMs) are significant in studies of membrane transport, incorporated proteins/ion transporters, and hence in construction of biosensor devices. Although BLMs provide an accepted mimic of cellular membranes, they are inherently fragile. Techniques are developed to stabilize them, such as hydrogel supports. In this paper, we present a reusable device for studies on hydrogel supported (hs) BLMs. These are formed across an ethylene tetrafluoroethylene (ETFE) aperture array supported by the hydrogel, which is during in situ polymerization covalently "sandwiched" between the ETFE substrate and a gold electrode microchip, thus allowing direct electrochemical studies with the integrated working electrodes. Using electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy and contact angle measurements, we demonstrate the optimized chemical modifications of the gold electrode microchips and plasma modification of the ETFE aperture arrays facilitating covalent "sandwiching" of the hydrogel. Both fluorescence microscopy and EIS were used to demonstrate the induced spontaneous thinning of a deposited lipid solution, leading to formation of stabilized hsBLMs on average in 10 min. The determined specific membrane capacitance and resistance were shown to vary in the range 0.31-0.49 μF/cm(2) and 45-65 kΩ cm(2), respectively, corresponding to partially solvent containing BLMs with an average life time of 60-80 min. The characterized hsBLM formation and devised equivalent circuit models lead to a schematic model to illustrate lipid molecule distribution in hydrogel-supported apertures. The functionality of stabilized hsBLMs and detection sensitivity of the platform were verified by monitoring the effect of the ion transporter valinomycin.

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“…[35] coated CdSe-ZnS core-shell QDs with a silica shell and covalently coupled them to MBs (Fig. 3d), since traditional water-soluble QDs coupled with MBs suffer from problems such as photoluminescence degradation, and chemical and colloidal instabilities in harsh environments (e.g., low-pH buffer).…”

Section: Quantum Dotsmentioning

confidence: 99%

“…When an excited-state molecule is brought close to a [29][30][31][32]40]; b MB containing a QD as a PLS and a gold nanoparticle as a quencher [33]; c MB containing a QD and an organic dye to form a dual-emission MB [34]; dMB containing a QD with a silica shell and an organic dye for a more stable dual-emission MB [35]; e MB containing a QD as a PLS and graphene oxide (GO) as a quencher [23] molecule in the ground state, an excimer is formed whose emission is redshifted from the emission of the monomer [43]. To date, pyrene has been employed as a PLS to signal the presence of small molecules [44], nucleic acids [45], and proteins [46].…”

Section: Pyrene Excimermentioning

confidence: 99%

Recent trends in molecular beacon design and applications

Huang

Martí

2011

Anal Bioanal Chem

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A molecular beacon (MB) is a hairpin-structured oligonucleotide probe containing a photoluminescent species (PLS) and a quencher at different ends of the strand. In a recognition and detection process, the hybridization of MBs with target DNA sequences restores the strong photoluminescence, which is quenched before hybridization. Making better MBs involves reducing the background photoluminescence and increasing the brightness of the PLS, which therefore involves the development of new PLS and quenchers, as well as innovative PLS-quencher systems. Heavy-metal complexes, nanocrystals, pyrene compounds, and other materials with excellent photophysical properties have been applied as PLS of MBs. Nanoparticles, nanowires, graphene, metal films, and many other media have also been introduced to quench photoluminescence. On the basis of their high specificity, selectivity, and sensitivity, MBs are developed as a general platform for sensing, producing, and carrying molecules other than oligonucleotides.

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Robust silica-coated quantum dot–molecular beacon for highly sensitive DNA detection

Cited by 41 publications

References 29 publications

An ultrasensitive SiO2-encapsulated alloyed CdZnSeS quantum dot-molecular beacon nanobiosensor for norovirus

An ultrasensitive SiO2-encapsulated alloyed CdZnSeS quantum dot-molecular beacon nanobiosensor for norovirus

A reusable device for electrochemical applications of hydrogel supported black lipid membranes

Recent trends in molecular beacon design and applications

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