Pu Zhang

Bio: Pu Zhang is an academic researcher from Southwest University. The author has contributed to research in topics: Materials science & Electrochemiluminescence. The author has an hindex of 19, co-authored 23 publications receiving 1343 citations.

One-pot hydrothermal synthesis of highly luminescent nitrogen-doped amphoteric carbon dots for bioimaging from Bombyx mori silk – natural proteins

Abstract: Nitrogen-doped carbon dots (CDs) have attracted great interest due to their extraordinary properties, especially their enhanced emission efficiency, and thus a facile synthesis of nitrogen-doped CDs with high emission efficiency is critical for practical applications. To improve the emission efficiency of CDs, herein we employed Bombyx mori silk, which has high nitrogen content, as a raw material to prepare photoluminescent nitrogen-doped carbon dots through one-pot hydrothermal synthesis, and found that the as-prepared CDs have a photoluminescence (PL) quantum yield of 13.9%, and display amphoteric properties depending on the pH, are highly photostable, have low toxicity and are suitable for bioimaging.

Highly Ordered and Field-Free 3D DNA Nanostructure: The Next Generation of DNA Nanomachine for Rapid Single-Step Sensing.

Abstract: Herein, by directly using Watson–Crick base pairing, a highly ordered and field-free three-dimensional (3D) DNA nanostructure is self-assembled by azobenzene (azo)-functionalized DNA nippers in a few minutes, which was applied as a 3D DNA nanomachine with an improved movement efficiency compared to traditional Au-based 3D nanomachines due to the organized and high local concentration of nippers on homogeneous DNA nanostructure. Once microRNA (miRNA) interacts with the 3D nanomachine, the nippers “open” to hybridize with the miRNA. Impressively, photoisomerization of the azo group induces dehybridization/hybridization of the nippers and miRNA under irradiation at different wavelengths, which easily solves one main technical challenge of DNA nanotechnology and biosensing: reversible locomotion in one step within 10 min. As a proof of concept, the described 3D machine is successfully applied in the rapid single-step detection of a biomarker, which gives impetus to the design of new generations of mechanical ...

Bi-directional DNA Walking Machine and Its Application in an Enzyme-Free Electrochemiluminescence Biosensor for Sensitive Detection of MicroRNAs.

Abstract: Herein, a dual microRNA (miRNA) powered bi-directional DNA walking machine with precise control was developed to fabricate an enzyme-free biosensor on the basis of distance-based electrochemiluminescence (ECL) energy transfer for multiple detection of miRNAs. By using miRNA-21 as the driving force, the DNA walker could move forth along the track and generated quenching of ECL response due to the proximity between Au nanoparticles (AuNPs) and Mn2+ doped CdS nanocrystals (CdS:Mn NCs) film as the ECL emitters, realizing ultrasensitive determination of miRNA-21. Impressively, once miRNA-155 was introduced as the driving force, the walker could move back along the track automatically, and surface plasmon resonance (SPR) occurred owing to the appropriate large separation between AuNPs and CdS:Mn NCs, achieving an ECL enhancement and realizing ultrasensitive detection of miRNA-155. The bi-directional movement of the DNA walker on the track led to continuous distance-based energy transfer from CdS:Mn NCs film by ...

Rapid synthesis of highly luminescent and stable Au20 nanoclusters for active tumor-targeted imaging in vitro and in vivo

Abstract: Rapid synthesis of protein-stabilized Au20 nanoclusters (Au20NCs) with high fluorescence quantum yield (QY) up to ∼15% is successfully achieved by manipulating the reaction kinetics. The as-obtained Au20NCs, identified by mass spectrometry, have an average size of 2.6 nm, with strong fluorescence emission at 620 nm (2.00 eV) upon excitation at either 370 nm (3.35 eV) or 470 nm (2.64 eV). The advantages of the as-obtained Au20NCs, including small sizes, high fluorescence QY, excellent photostability, non-toxicity, and good stability in biological media, make them ideal candidates as good luminescent probes for optical imaging in vitro and in vivo. Our results demonstrate that the uptake of Au20NCs by both cancer cells and tumor-bearing nude mice can be improved by receptor-mediated internalization, compared with that by passive targeting. Because of their selective accumulation at the tumor sites, the Au20NC probes can be used as potential indicators for cancer diagnosis. This work not only provides a new understanding of the rapid synthesis of highly luminescent Au20NCs but also demonstrates that the functionalized-Au20NCs are excellent probes for active tumor-targeted imaging in vitro and in vivo.

Versatile and Ultrasensitive Electrochemiluminescence Biosensor for Biomarker Detection Based on Nonenzymatic Amplification and Aptamer-Triggered Emitter Release.

Abstract: Electrochemiluminescence (ECL), as a sensitive and controllable assay, offers a considerable opportunity for multiple types of biomarkers detection. However, constructing such a biosensor remains a significant challenge. Herein, an ultrasensitive and versatile ECL biosensor was constructed to detect multiple types of biomarkers from breast cancer by taking the strategies of nonenzymatic catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR) amplification, as well as aptamer-triggered emitter release. Concretely, with the appearance of target 1 microRNA-21 (miRNA-21), abundant double-stranded DNA (dsDNA) polymers were generated on this biosensing surface via amplification circuits of CHA and HCR, which could be intercalated into substantial ([Ru(bpy)2dppz]Cl2) as ECL indicators to obtain an obvious enhancement of ECL signal for target 1 detection with a detection limit (0.1 fM). Furthermore, in the presence of target 2 human mucin 1 (MUC1) protein, the ECL signal had a distinct decrease, b...

Atomically Precise Colloidal Metal Nanoclusters and Nanoparticles: Fundamentals and Opportunities

Abstract: Colloidal nanoparticles are being intensely pursued in current nanoscience research. Nanochemists are often frustrated by the well-known fact that no two nanoparticles are the same, which precludes the deep understanding of many fundamental properties of colloidal nanoparticles in which the total structures (core plus surface) must be known. Therefore, controlling nanoparticles with atomic precision and solving their total structures have long been major dreams for nanochemists. Recently, these goals are partially fulfilled in the case of gold nanoparticles, at least in the ultrasmall size regime (1–3 nm in diameter, often called nanoclusters). This review summarizes the major progress in the field, including the principles that permit atomically precise synthesis, new types of atomic structures, and unique physical and chemical properties of atomically precise nanoparticles, as well as exciting opportunities for nanochemists to understand very fundamental science of colloidal nanoparticles (such as the s...

Glowing Graphene Quantum Dots and Carbon Dots: Properties, Syntheses, and Biological Applications

Abstract: The emerging graphene quantum dots (GQDs) and carbon dots (C-dots) have gained tremendous attention for their enormous potentials for biomedical applications, owing to their unique and tunable photoluminescence properties, exceptional physicochemical properties, high photostability, biocompatibility, and small size. This article aims to update the latest results in this rapidly evolving field and to provide critical insights to inspire more exciting developments. We comparatively review the properties and synthesis methods of these carbon nanodots and place emphasis on their biological (both fundamental and theranostic) applications.

Gold nanorods and their plasmonic properties

Abstract: Gold nanorods have been receiving extensive attention owing to their extremely attractive applications in biomedical technologies, plasmon-enhanced spectroscopies, and optical and optoelectronic devices. The growth methods and plasmonic properties of Au nanorods have therefore been intensively studied. In this review, we present a comprehensive overview of the flourishing field of Au nanorods in the past five years. We will focus mainly on the approaches for the growth, shape and size tuning, functionalization, and assembly of Au nanorods, as well as the methods for the preparation of their hybrid structures. The plasmonic properties and the associated applications of Au nanorods will also be discussed in detail.

Review on recent advances in nitrogen-doped carbons: preparations and applications in supercapacitors

Abstract: It is of great interest to develop new carbon-based materials as electrodes for supercapacitors because the conventional electrodes of activated carbons in supercapacitors cannot meet the ever-increasing demands for high energy and power densities for electronic devices. Due to their high electronic conductivity and improved hydrophilic properties, together with their easy syntheses and functionalization, N-doped carbons have shown a great potential in energy storage and conversion applications. In this review, after a brief introduction of electrochemical capacitors, we summarize the advances, in the recent six years, in the preparation methods of N-doped carbons for applications in supercapacitors. We also discuss and predict futuristic research trends towards the design and syntheses of N-doped carbons with unique properties for electrochemical energy storage.