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A novel multifunctional nanoprobe was designed for cancer cell targeted multilayer imaging of two cancer biomarkers. Based on the proposed method, in situ imaging of membrane MUC1 mucin and cytoplasmic microRNA miR-21 coupled with precise photodynamic therapy was achieved. [ABSTRACT FROM AUTHOR]

Cation-exchange-based chemiluminescence amplification (CXCLAmp) was developed in this study. After amplification by rolling circle amplification (RCA), the proposed RCA–CXCLAmp strategy was used to detect miRNA sensitively. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are short non-coding RNAs that are involved in the epigenetic regulation of cellular processes. To identify more miRNAs which are involved in the macrophage inflammatory response to lipopolysaccharide (LPS) stimulation and dissect the mechanisms more clearly, microRNA profiling of LPS-treated RAW264.7 macrophage cells was performed by initial high-throughput array-based screen and further real-time RT-PCR validation; bioinformatics approaches were used to analyze the target genes of the differentially expressed miRNAs. Compared to the untreated control, two microRNAs (miR-146a and miR-155) with more than twofold higher expression and two microRNAs (miR-27a* and miR-532-5p) with twofold lower expression were detected by array-based screen, which can be validated by qRT-PCR, and more than 1,000 candidate target genes were detected by at least of one of four different algorithms (TargetScan, PicTar, miRDB, and microRNA.org); with gene ontology classification, we were able to correlate the upregulation and downregulation of miRNA to the differential expression of inflammation-related candidate target gene during LPS-induced inflammation. Our findings may provide the basic information for the precise roles of miRNAs in the macrophage inflammatory response to LPS stimulation in the future. [ABSTRACT FROM AUTHOR]

A novel method of catalytic hairpin assembly (CHA) induced dual signal enhancement is developed for rapid detection of miRNA based on fluorescence light-up silver nanocluster (Ag NC). By the hybridization of a hairpin DNA and a single-stranded DNA, a unique probe is firstly designed. In the terminals of this probe, DNA-Ag NCs can be formed and display very weak fluorescence. In the presence of the target miRNA, the reaction of CHA can be triggered, forming two kinds of double-stranded complexes, in which the terminal DNA-Ag NCs are in close proximity to G-rich overhangs and the fluorescent signal can be dramatically enhanced. Compared with many other enzyme-based amplification strategies, this one exhibits distinct advantages of simplicity in experimental operation and a rapid detection process (within 1 h). Moreover, this assay exhibits an excellent selectivity and is successfully applied in the detection of miRNAs in complex biological media, which confirms the reliability and practicality of this protocol. A novel method of catalytic hairpin assembly (CHA) induced dual signal enhancement is developed, which has been used for rapid detection of miRNA based on fluorescence light-up silver nanocluster. Image 1 • A novel method of catalytic hairpin assembly induced dual signal enhancement is developed. • The method is used for miRNA detection based on fluorescence light-up silver nanocluster. • This assay has the advantages of simplicity in experimental operation and a rapid detection process. [ABSTRACT FROM AUTHOR]

Abstract A sensitive surface-enhanced Raman scattering (SERS) approach has been developed for detection of microRNA (miRNA) based on target-triggered dual signal amplification including strand displancement amplification (SDA) and hybridization chain reaction (HCR). With the assistant of polymerase and nicking endonuclease (NEase), target miRNA combines with the single stranded template DNA to generate a great amount of trigger DNA which can induce HCR. Coupled the dual cycle amplification of SDA and HCR with the dual enhancement of gold nanoparticles (AuNPs), a low detection limit of 0.5 fM for miRNA is obtained using the proposed strategy. With high sensitivity, universality, rapid analysis, and high selectivity, this method has a great potential for detecting biomolecules with trace amounts in bioanalysis and clinical biomedicine. Highlights • A novel method of dual cycle amplification and dual signal enhancement assisted SERS detection for miRNA is developed. • This method allows the transduction of miRNA detection into DNA-based signal amplification. • This assay has the advantages of wide dynamic range, high sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

Despite the great promise of cancer theranostic platforms, accurate diagnosis and effective treatment are still highly challenging. In this work, nanodevice for intracellular miRNAs detection and artificially controlled drug releasement was developed based on upconverting nanoparticles (UCNPs). For analysis aspect, DNAzymes amplified miRNA-21 detection was carried out, giving excellent sensitivity with detection limits of 1.8 × 10-11 M. Moreover, intracellular fluorescence imaging permitted in situ diagnoses of miRNA-21 expression in living cells. Once the test identifies tumor markers, treatment can be performed. Here, artificially controlled chemo-gene synergetic therapy nanodevice was obtained by integrating UCNPs with photocleavable linkers (PC-linkers). In vitro and in vivo experiments verified the potential application of prepared nanodevice in cancer theranostics. [ABSTRACT FROM AUTHOR]

• DNA walker was employed with signal amplification. • The cation exchange reaction was used to change the PEC signal. • The proposed strategy exhibited an excellent sensitivity, specificity and was used in real sample assay. MicroRNAs (miRNAs), a kind of important biomarker, are traced and quantitatively detected in early clinical analysis. An ultrasensitive photoelectrochemical (PEC) sensing platform was constructed for microRNA 141 (miR-141) detection based on target triggered DNA walker amplification and silver nanoparticle assisted cation exchange. In this protocol, DNA walker was made of assembled DNA structure on the surface of gold nanoparticles (AuNPs), which powered by target to generate intermediate DNA. After hybridization and endonuclease digestion, the intermediate DNA was converted to numerous silver ions through the T7 exonuclease-aided recycling and acidolysis. Then, the released silver ions were introduced to CdSe QDs and initiated the ion exchange reaction on the electrode, resulting in largely change of PEC signal. The CdSe QDs/TiO 2 composites with high photocatalytic activity were employed as PEC substrate. The photocurrent was decreased after ion exchange reaction. Through introducing amazing signal amplification strategy, the developed PEC "on-off" biosensor permitted a detection limit down to 3.0 aM for miR-141, and with a linear range from 1.0 × 10−17 to ×10-13 M. [ABSTRACT FROM AUTHOR]