Modular Weaving DNAzyme in Skeleton of DNA Nanocages for Photoactivatable Catalytic Activity Regulation.

DNAzymes exhibit tremendous application potentials in the field of biosensing and gene regulation due to its unique catalytic function. However, spatiotemporally controlled regulation of DNAzyme activity remains a daunting challenge, which may cause nonspecific signal leakage or gene silencing of the catalytic systems. Here, we report a photochemical approach via modular weaving active DNAzyme into the skeleton of tetrahedral DNA nanocages (TDN) for light-triggered on-demand liberation of DNAzyme and thus conditional control of gene regulation activity.

Modular Engineering of DNAzyme-Based Sensors for Spatioselective Imaging of Metal Ions in Mitochondria.

DNAzyme-based sensors remain at the forefront of metal-ion imaging efforts, but most lack the subcellular precision necessary to their applications in specific organelles. Here, we seek to overcome this limitation by presenting a DNAzyme-based biosensor technology for spatiotemporally controlled imaging of metal ions in mitochondria. A DNA nanodevice was constructed by integrating an optically activatable DNAzyme sensor and an upconversion nanoparticle with an organelle-targeting signal.

Near-infrared-emitting upconverting BiVO nanoprobes for in vivo fluorescent imaging.

Near-infrared (NIR) emitting BiVO:Yb,Tm nanoparticles are synthesized by a new solvothermal strategy using solvents of oleic acid and methanol. The obtained BiVO:Yb,Tm samples show an average particle size of ≈164 nm and exhibit an asymmetry monoclinic crystal structure of BiVO. At NIR excitation of 980 nm, the BiVO:Yb,Tm sample exhibits a nearly single NIR emission at ≈796 nm with extremely weak blue emissions from Tm ions.

Enzyme-triggered DNA nanomimosa: A ratiometric nanoprobe for RNase H activity sensing in living cells.

Since ribonuclease H (RNase H) exhibits its importance in a variety of cellular processes. It is necessary to establish strategy for RNase H detection. In this work, we are enlightened by mimosa, a natural plant which can fold in response to stimuli, to construct a DNA tetrahedron-based nanoprobe, termed DNA nanomimosa, to sensing RNase H activity based on fluorescent resonance energy transfer (FRET).

Polydopamine nanodots-based cost-effective nanoprobe for glucose detection and intracellular imaging.

The cellular glucose detection remains a vital topic, which could provide some essential information about the glucose-based pathological and physiological processes. In this study, a smart polydopamine nanodots-based cost-effective fluorescence turn-on nanoprobe (denoted as PDA-Ag-GOx) for intracellular glucose detection is established. Silver nanoparticles (AgNPs) are directly formed in one step by the reduction of fluorescent polydopamine nanodots (PDADs) which have much phenolic hydroxyls on the surface.

A dual-functional biomimetic-mineralized nanoplatform for glucose detection and therapy with cancer cells .

Glucose detection is a crucial topic in the diagnosis of numerous diseases, such as hypoglycemia or diabetes mellitus. Research indicates that people with diabetes mellitus are at a higher risk of developing various types of cancer. A nanoplatform that combines both diabetes diagnosis and cancer therapy might be regarded as a more effective way to solve the above-mentioned problem.

One-step G-quadruplex-based fluorescence resonance energy transfer sensing method for ratiometric detection of uracil-DNA glycosylase activity.

Uracil-DNA glycosylase (UDG) is a crucial enzyme in base excision repair (BER) pathway. It can repair the uracil-induced DNA lesions and maintain the integrity of genome. In this paper, we developed a facile and ratiometric strategy for UDG activity detection using fluorescence resonance energy transfer (FRET).

Enhanced in Vivo Blood-Brain Barrier Penetration by Circular Tau-Transferrin Receptor Bifunctional Aptamer for Tauopathy Therapy.

The lack of blood-brain barrier (BBB) penetrating ability has hindered the delivery of many therapeutic agents for tauopathy treatment. In this study, we report the synthesis of a circular bifunctional aptamer to enhance the in vivo BBB penetration for better tauopathy therapy. The circular aptamer consists of one reported transferrin receptor (TfR) aptamer to facilitate TfR-aptamer recognition-induced transcytosis across BBB endothelial cells, and one Tau protein aptamer that we recently selected to inhibit Tau phosphorylation and other tauopathy-related pathological events in the brain.

Label-free fluorescent assay of T4 polynucleotide kinase phosphatase activity based on G-quadruplexe-thioflavin T complex.

T4 polynucleotide kinase phosphatase (T4 PNKP) is a bifunctional tool enzyme with 5'-kinase and 3'-phosphatase activities. Considering its important roles in the repair of strand breaks, assay of T4 PNKP activity is of great importance. In this work, we proposed a novel label-free sensing strategy for T4 PNKP activity based on G-quadruplexe-thioflavin T fluorescent indicator.

Rapid and sensitive detection of potassium ion based on K(+)-induced G-quadruplex and guanine chemiluminescence.

A simple and rapid method for detection of potassium ion (K(+)) based on a guanine chemiluminescence (CL) system is presented. In this system, one guanine-rich DNA molecule is used as the recognition element. K(+) can cause the guanine-rich DNA to form a G-quadruplex conformation, resulting in remarkable quenching of the guanine CL intensity of guanine-rich DNA.

[Comparison of bacterial diversity of polluted and unpolluted sediment by brominated flame retardant].

Objective: By using brominated flame retardant we compared the bacterial diversity of highly polluted river sediment with that of nearby unpolluted lake.

Method: Total DNA was extracted from unpolluted and highly polluted sediment sample by brominated flame retardant in Guiyu of China. The 16S rRNA gene was amplified by PCR using bacterial primer 27F and 1500R.