Publications by authors named "Ai-Xian Zheng"

Background: Standard and proper antituberculosis (anti-TB) treatment is essential for patients with TB, and rifamycin antibiotics are key components of anti-TB therapy. Therapeutic drug monitoring (TDM) of rifamycin antibiotics can shorten the time to response and complete treatment of TB. Notably, antimicrobial activities of the major active metabolites of rifamycin are similar to those of their parent compounds.

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Prerelease of RNA molecules than chemotherapeutic drugs with a sufficient interval is a vital prerequisite for RNA/drug co-delivery strategy to overcome multidrug resistance (MDR) of cancer cells, but how to precisely control their release at different time points is still a grand challenge up to now. This study aims to on-demand remotely manipulate RNA and drug release in real time through single delivery system to sequentially play their respective roles for optimizing and enhancing their synergistic antitumor effects. To this end, a photoresponsive mesoporous silica nanoparticle (PMSN) is fabricated as a co-delivery vehicle of P-glycoprotein (P-gp) short-hairpin RNA (shRNA) and photocaged prodrug of doxorubicin (DOX), by which the orthogonal and sequential release of shRNA and DOX can be achieved using an external light.

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We developed a facile one-step approach to synthesize DNA-templated Ag/Pt bimetallic nanoclusters (DNA-Ag/Pt NCs), which possess highly-efficient peroxidase-like catalytic activity. With this finding, an aptamer based sandwich-type strategy is employed to design a label-free colorimetric aptasensor for the protein detection with high sensitivity and selectivity.

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In recent years, considerable efforts have been devoted to the construction of efficient enzyme mimetics, which have significant advantages of simple synthesis, good stability and design flexibility. In this paper, we described that graphene dots (GDs) possess highly-efficient peroxidase-like catalytic activity, and its activity is much higher than graphene oxide (GO) with large size. They can catalyze the oxidation of peroxidase substrate 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H2O2 to produce a blue product, which can be used for H2O2 detection by measuring the absorbance change.

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A simple turn-on and homogeneous aptasensor, which relies on target induced formation of silver nanoclusters (Ag NCs), was developed for the determination of platelet-derived growth factor B-chain homodimer (PDGF-BB). The aptasensor contains two hairpin DNA probes termed as P1 and P2. P1 consists of the aptamer sequence of PDGF-BB.

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In this work, we developed a simple and general method for highly sensitive detection of proteins and small molecules based on cyclic enzymatic signal amplification (CESA) and hairpin aptamer probe. Our detection system consists of a hairpin aptamer probe, a linker DNA, two sets of DNA-modified AuNPs, and nicking endonuclease (NEase). In the absence of a target, the hairpin aptamer probe and linker DNA can stably coexist in solution.

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Aptamers have many advantages, such as simple synthesis, good stability, high binding affinity and wide applicability, making them suitable candidates for protein detection. Since the disease-related protein may be present in very small amounts in biological samples, the development of amplification paths for aptasensors is essential. In this paper, we develop a simple and enzyme-free amplified aptasensor for protein detection via target-catalyzed hairpin assembly.

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A simple, highly sensitive and enzyme-free DNAzyme sensor based on target-catalyzed hairpin assembly is developed, which permits detection of 0.1 pM target DNA. Furthermore, this DNAzyme sensor is capable of detecting target DNA in real samples because of its high selectivity.

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A simple and highly sensitive homogeneous aptasensor is developed, which relies on nicking enzyme. The sensitivity of this newly proposed aptasensor is about three orders of magnitude higher than that of traditional homogeneous aptasensors. Furthermore, it is capable of detecting target protein in real samples.

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Peptide-protein interactions have critical roles in biology. Monitoring peptide-protein interactions plays an important role in investigating molecular recognition, screening drugs, and designing biosensors. In this paper, we develop a novel fluorescent approach to monitor peptide-protein interactions based on the assembly of pyrene-labeled peptide and graphene oxide (GO).

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