In this article, we describe a carbon nanotube (CNT)-based lateral flow biosensor (LFB) for rapid and sensitive detection of DNA sequence. Amine-modified DNA detection probe was covalently immobilized on the shortened multi-walled carbon nanotubes (MWCNTs) via diimide-activated amidation between the carboxyl groups on the CNT surface and amine groups on the detection DNA probes. Sandwich-type DNA hybridization reactions were performed on the LFB and the captured MWCNTs on test zone and control zone of LFB produced the characteristic black bands, enabling visual detection of DNA sequences.
View Article and Find Full Text PDFIn this work, we present a simple and fast approach for simultaneous detection of nucleic acid and protein using gold nanoparticles (GNPs) and a lateral flow device (LFD). Sandwich-type immunoreactions and DNA hybridizations were performed simultaneously on the LFD by using DNA- and antibody-functionalized GNPs. The captured GNPs, due to the DNA hybridization and immunoreaction events on the LFD, produced characteristic red bands that could be used for the qualitative detections of DNA and/or protein.
View Article and Find Full Text PDFBiosens Bioelectron
April 2014
We report a DNA-gold nanoparticle (DNA-GNP) based lateral flow nucleic acid biosensor for visual detection of microRNA (miRNA)-215 in aqueous solutions and biological samples with low-cost and short analysis time. Sandwich-type hybridization reactions among GNP-labeled DNA probe, miRNA-215 and biotin-modified DNA probes were performed on the lateral flow device. The accumulation of GNPs on the test zone of the biosensor enables the visual detection of miRNA-215.
View Article and Find Full Text PDFHere, we describe a simple and sensitive approach for visual detection of gene mutations based on isothermal strand-displacement polymerase reactions (ISDPR) and lateral flow strip (LFS). The concept was first demonstrated by detecting the R156H-mutant gene of keratin 10 in Epidermolytic hyperkeratosis (EHK). In the presence of biotin-modified hairpin DNA and digoxin-modified primer, the R156H-mutant DNA triggered the ISDPR to produce numerous digoxin- and biotin-attached duplex DNA products.
View Article and Find Full Text PDFWe report a sensitive method for visual detection of mercury ions (II) (Hg²⁺) in aqueous solution by using gold nanoparticles (Au-NPs) and thymine (T)-rich hairpin DNA probes. The thiolated hairpin DNA probe was immobilized on the Au-NP surface through a self-assembling method. Another thymine-rich, digoxin-labeled DNA probe was introduced to form DNA duplexes on the Au-NP surface with thymine-Hg²⁺-thymine (T-Hg²⁺-T) coordination in the presence of Hg²⁺.
View Article and Find Full Text PDFIn this article, we describe an ultrasensitive nucleic acid biosensor (NAB) based on horseradish peroxidase (HRP)-gold nanoparticle (Au-NP) dual labels and lateral flow strip biosensor (LFSB). The results presented here expand on prior work (Mao et al., 2009a) by optimizing the preparation of HRP-Au-NP-DNA conjugates.
View Article and Find Full Text PDFWe report a simple, fast, and sensitive approach for visual detection of single-nucleotide polymorphism (SNP) based on hairpin oligonucleotide-functionalized gold nanoparticle (HO-Au-NP) and lateral flow strip biosensor (LFSB). The results presented here expand on prior work ( Mao , X. , Xu , H.
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