3D SERS substrate based on nanocone forests for miRNA detections

Surface-enhanced Raman scattering(SERS)is a powerful technology for obtaining vibrational information from molecules that present in different chemical or biological environments.This paper presents a 3D SERS substrate based on nanocone forests.The substrates are prepared by using plasma treatment technique,which is a simple,fast and high-throughput approach.The SERS substrate based on nanocone forests exhibits high sensitivity.In the experiment,miRNA with a concentration as low as 10-10 M can be achieved.Meanwhile,the proposed SERS substrate shows a high uniformity over a large area.These experimental results demonstrate great potential of the 3D SERS substrate in wide applications.

Magnetic covalent organic framework nanospheres-based miRNA biosensor for sensitive glioma detection

Sensitive detection and accurate diagnosis/prognosis of glioma remain urgent challenges.Herein,dispersed magnetic covalent organic framework nanospheres(MCOF)with uniformed Fe3O4 nano-assembly as cores and high-crystalline COF as shells were prepared by monomer-mediated in-situ interface growth strategy.Based on the unique interaction between MCOF and hairpin DNA,a fluorescent signal amplified miRNA biosensor was constructed.It could realize the sensitive detection of miRNA-182 in different matrixes,where the detection limit,linearity range and determination coefficient(R^(2))in real blood samples reached 20 fM,0.1 pM-10 pM and 0.991,respectively.Also,it possessed good stability and precision as observed from the low intra-day/inter-day RSD and high extraction recovery.As a result,it could quantify miRNA-182 in serum of glioma patients,the concentration of which was significantly higher than that of healthy people and obviously decreased after surgery.Finally,a proof-of-concept capillary chip system using this biosensor was proposed to realize the visualized detection of miRNA-182 in microsample.These findings suggest a robust way for sensitive detection and accurate diagnosis/prognosis of glioma.

Zeptomole Imaging of Cytosolic MicroRNA Cancer Biomarkers with A Light-Controlled Nanoantenna

Detecting and quantifying intracellular microRNAs(miRNAs)are a critical step in resolving a cancer diagnostic and resolving the ensemble of gene products that orchestrate the living state of cells.However,the nanoprobe for detecting low abundance miRNAs in cell cytosol is restricted by either the"one-to-one"signaltrigger model or di culty for cytosol delivery.To address these challenges,we designed a lightharvesting nanoantenna-based nanoprobe,which directs excitation energy to a single molecule to sensitively detect cytosolic miRNA.With light irradiation,the light-harvesting nanoantenna e ectively disrupted lysosomal structures by generationof reactive oxygen species,substantially achieved cytosol delivery.The nanoantenna containing>4000 donor dyes can e ciently transfer excitation energy to one or two acceptors with 99%e ciency,leading to unprecedented signal amplification and biosensing sensitivity.The designed nanoantenna can quantify cytosolic miR-210 at zeptomolar level.The fluorescence lifetime of the donor exhibited good relationship with miR-210 concentration in the range of 0.032 to 2.97 amol/ngRNA.The zeptomole sensitivity of nanoantenna provides accurate bioimaging of miR-210 both in multiple cell lines and in vivo assay,which creates a pathway for the creation of miRNA toolbox for quantitative epigenetics and personalized medicine.

MicroRNA: a new and promising potential biomarker for diagnosis and prognosis of ovarian cancer

Epithelial ovarian cancer(EOC) is the leading cause of death among all gynecological malignancies. Despite the technological and medical advances over the past four decades, such as the development of several biological markers(mRNA and proteins biomarkers), the mortality rate of ovarian cancer remains a challenge because of its late diagnosis, which is specifically attributed to low specificities and sensitivities. Under this compulsive scenario, recent advances in expression biology have shifted in identifying and developing specific and sensitive biomarkers, such as micro RNAs(miRNAs) for cancer diagnosis and prognosis. MiRNAs are a novel class of small non-coding RNAs that deregulate gene expression at the posttranscriptional level, either by translational repression or by mRNA degradation. These mechanisms may be involved in a complex cascade of cellular events associated with the pathophysiology of many types of cancer. MiRNAs are easily detectable in tissue and blood samples of cancer patients. Therefore, miRNAs hold good promise as potential biomarkers in ovarian cancer. In this review, we attempted to provide a comprehensive profile of key miRNAs involved in ovarian carcinoma to establish mi RNAs as more reliable non-invasive clinical biomarkers for early detection of ovarian cancer compared with protein and DNA biomarkers.

Photoluminescent two-dimensional SiC quantum dots for cellular imaging and transport

Two-dimensional （2D） ultrathin SiC has received intense attention due to its broad band gap and resistance to large mechanical deformation and external chemical corrosion. However, the synthesis and application of ultrasmall 2D SiC quantum dots （QDs） has not been explored. Herein, we synthesize a type of monolayered 2D SiC QDs with advanced photoluminescence （PL） properties via a facile hydrothermal route. Their average size and thickness can be easily adjusted by altering the reaction time. The ultrasmall 2D SiC QDs exhibit a long fluorescence lifetime of 2.59 ps due to efficient quantum confinement. The applications of SiC QDs are demonstrated through labeling A549, HeLa, and NHDF cells and delivering agents for intracellular low-abundant microRNA （miRNA） detection. This advance in preparing photoluminescent SiC QDs is of great significance for broadening their potential in biomedical and optical applications.