A universal green synthesis approach for Glu-FeO quantum dots (QDs) with ultrasmall size (∼3.3 nm) and enhanced catalysis was demonstrated using glutamic acid (Glu) as a dopant. Abundant carboxylic groups and amino groups on the surfaces with a zeta potential of -6.
View Article and Find Full Text PDFThe rapid and accurate detection of miRNAs is of great significance for early diagnosis and treatment of cancer. Hence, a novel enzyme-free and label-free electrochemical biosensor based on bio-barcode amplification for detecting miRNAs was presented. Sandwich structures constructed of magnetic nanoparticles modified with DNA probes, gold nanoparticles with numerous barcoded DNA strands that hybridized with target miRNAs were fabricated as the amplifier.
View Article and Find Full Text PDFMercury ion (Hg) is the most widespread and highly toxic environmental pollutant, which exerts numerous adverse effects on environmental and human health. There is an urgent need to develop a convenient method for detecting Hg. Herein, a novel dual-mode sensor based on colorimetric and Tyndall effect of gold nanoparticles was developed for ultra-sensitive determination of Hg.
View Article and Find Full Text PDFSilver(I) ions (Ag) are harmful to humans and can be bioaccumulated in organisms. Although numerous methods for Ag analysis have been established, new strategies are still in urgent need. Here, we propose a colorimetric sensor based on polyadenine (polyA)-mediated DNA-functionalized gold nanoparticles (AuNPs) for the specific measurement of Ag ions.
View Article and Find Full Text PDFDNA methyltransferase (MTase) is an important regulatory enzyme in various biological processes. However, current methods for investigating MTase activity are still limited in terms of sensitivity and/or generality. Herein, we proposed a dual amplification fluorescence strategy for the ultrasensitive detection of DNA adenine methylation methyltransferase (Dam MTase) activity based on strand displacement amplification (SDA) coupled with rolling circle amplification (RCA).
View Article and Find Full Text PDFDNA methylation catalyzed by DNA adenine methylation methyltransferase (Dam MTase) is strongly connected with a variety of biological processes, hence, monitoring Dam MTase activity is of great importance. Here, we developed a rapid and sensitive fluorescence sensing strategy for the detection of Dam MTase activity based on methylation-blocked enzymatic recycling amplification. In this fluorescence sensing system, Dam MTase-induced methylation blocked the subsequent reactions.
View Article and Find Full Text PDFRolling circle amplification (RCA) has become an increasingly important amplification technique in nucleic acid analysis, immunoassay, and molecular diagnosis due to its high specificity and sensitivity. However, the accurate quantification of RCA products the extensively used fluorescent signaling method has been challenged primarily by the non-specific and sequence-independent binding of the fluorescent dyes to DNA. Here, we have developed a signal-on E-DNA sensor for accurate quantification of the RCA products with high specificity and sensitivity.
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