Hanmei Deng

Bio: Hanmei Deng is an academic researcher from Southwest University. The author has contributed to research in topics: Biosensor & Photocurrent. The author has an hindex of 8, co-authored 11 publications receiving 132 citations.

In Situ Formation of Multifunctional DNA Nanospheres for a Sensitive and Accurate Dual-Mode Biosensor for Photoelectrochemical and Electrochemical Assay.

Abstract: Herein a photoelectrochemical (PEC) and electrochemical (EC) dual-mode biosensor with cationic N,N-bis(2-(trimethylammonium iodide)propylene)perylene-3,4,9,10-tetracarboxydiimide (PDA+)-decorated multifunctional DNA spheres in situ generated on an electrode was proposed for sensitive and accurate detection of miRNA-141. By employing a target-related ternary "Y" structure cleavage cycling reaction, the target DNA was converted into massive output DNA anchored on a TiO2 substrate, and hence triggering the rolling circle amplification (RCA) reaction. Upon addition of magnesium ions and PDA+, the long DNA tails of the RCA product were condensed in situ to form multifunctional DNA spheres. Notably, the distance between DNA spheres and TiO2 substrate was short, thus forming an effective PDA+-TiO2 sensitization structure with fast electron transfer for acquiring an extremely enhanced PEC signal with assistance of ascorbic acid (AA). Meanwhile, cationic PDA+ with a large planar π-π skeleton enabled favorable redox-activity and substantial loading on DNA spheres, directly producing an obviously well-defined cathodic peak for implementing EC biodetection on the same sensing platform. This approach not only avoided difficult assembly of diverse signal indicators but also significantly improved the sensitivity by utilizing cleavage cycling amplification and RCA strategies. Moreover, the distinct dual-response signals from two different transduction mechanisms and independent signal transduction can mutually support accuracy improvement. As a result, detection ranges of 0.1 fM to 1 nM for PEC and 2 fM to 500 pM for EC were obtained for miRNA-141, providing a universal and efficient biosensing method with promising applications in bioanalysis and early disease diagnosis.

Ultrasensitive Photoelectrochemical Detection of Multiple Metal Ions Based on Wavelength-Resolved Dual-Signal Output Triggered by Click Reaction.

Abstract: In this work, a click reaction-triggered wavelength-resolved dual-signal output photoelectrochemical (PEC) biosensor with DNAzymes-assisted cleavage recycling amplification was proposed for sensiti...

Methylene blue sensitized photoelectrochemical biosensor with 3,4,9,10-Perylene tetracarboxylic acid film as photoelectric material for highly sensitive Pb2+ detection

Abstract: It is of great significance to explore reliable and sensitive methods for the trace detection of lead ions (Pb2+), which may cause serious adverse effect to human health Herein, we proposed a methylene blue (MB) sensitized signal-on photoelectrochemical (PEC) biosensor with 3,4,9,10-perylene tetracarboxylic acid (PTCA) film as photoelectric material for highly sensitive Pb2+ detection First, PTCA was modified on the electrode surface, manifesting wonderful film-forming property and acquiring a satisfactory initial PEC signal Afterward, Pb2+-dependent DNAzyme modified on electrode was cleaved by target Pb2+, followed by hybridizing MB assembled 3D DNA networks with the exposed Pb2+ catalytic strand Significantly, in the presence of sensitizer MB, the PEC signal of PTCA was extraordinarily increased and the designed biosensor performed a high sensitivity with a detection limit down to 003 pM Therefore, with enzyme-free assembly of MB embedded 3D DNA networks, this dye-sensitized strategy exhibited effective and uncomplicated amplification technology for Pb2+ detection

Novel D-A-D-Type Supramolecular Aggregates with High Photoelectric Activity for Construction of Ultrasensitive Photoelectrochemical Biosensor.

Abstract: In this work, hydrazine-functionalized perylene diimide derivative supramolecular (HPDS), a novel self-enhanced donor–acceptor-donor (D-A-D) type aggregates with excellent photoelectric activity, w...

Recent advances in photoelectrochemical biosensors for analysis of mycotoxins in food

Abstract: Mycotoxins, highly toxic secondary metabolites of fungus, have brought considerable threats to human health. It is of great significance to develop low-cost, rapid and efficient analytical methods for monitoring mycotoxins in foodstuffs. Photoelectrochemical (PEC) biosensors have been promising tools for mycotoxin detection thanks to their superior properties. Photoactive materials play important roles in the biosensing systems as transducer converting chemical information into detectable PEC signal. Signal strategies based on specific recognition elements also affects a lot on the analytical performance of PEC biosensors. This paper provides a comprehensive review on photoactive materials and signal strategies used in the PEC biosensors for mycotoxin monitoring. The future prospects in this field are also discussed.

Advances in photocatalysis based on fullerene C60 and its derivatives: Properties, mechanism, synthesis, and applications

Abstract: Fullerenes possess high chemical stability, large specific surface area, good electrical conductivity and unique three-dimensional structure. In this paper, we provide a general overview of the latest research results of fullerene-based photocatalysts. Firstly, the current status of semiconductor materials and fullerenes in photocatalytic applications are briefly introduced. Secondly, introduced action mechanisms of photocatalysts modified by fullerene C60 and its derivatives, including basic structure, exclusive properties and its effect in photocatalysis and material preparation process. Thirdly, factors affecting material effectiveness and the synthesis strategy of composite photocatalyst modified by fullerene are introduced. Meanwhile, the application advances of the photocatalysts are introduced, including in the degradation of pollutants, organic synthesis, hydrogen production, antibacterial and disinfection in water. Finally, the development trends of fullerenes and their derivatives in photocatalysis are also summarized, including theoretical calculations, the morphological structure control, stable derivatives and increase the selectivity, and new other types of fullerene materials.

Integrating CRISPR-Cas12a with a DNA circuit as a generic sensing platform for amplified detection of microRNA

Abstract: CRISPR-based diagnostics (CRISPR-Dx) has shown great promise in molecular diagnostics, but its utility in the sensing of microRNA (miRNA) biomarkers is limited by sensitivity, cost and robustness Here, we describe a CRISPR-Dx method for the sensitive and cost-effective detection of miRNAs by rationally integrating CRISPR-Cas12a with DNA circuits In this work, a modular catalytic hairpin assembly (CHA) circuit is designed to convert and amplify each target into multiple programmable DNA duplexes, which serve as triggers to initiate the trans-cleavage activity of CRISPR-Cas12a for further signal amplification Such rational integration provides a generic assay for the effectively amplified detection of miRNA biomarkers By simply tuning the variable regions in the CHA modules, this assay achieves sub-femtomolar sensitivity for different miRNA biomarkers, which improves the detection limit of CRISPR-Dx in the analysis of miRNA by 3–4 orders of magnitude With the usage of the proposed assay, the sensitive assessment of miR-21 levels in different cancer cell lines and clinical serum samples has been achieved, providing a generic method for the sensitive detection of miRNA biomarkers in molecular diagnosis