Publications by authors named "De-Man Han"

Background: The progress of modern research is constantly fueled by the convergence of multiple technologies. Despite the enormous potential of both fluorescence (FL) and photoelectrochemical (PEC) technologies, the development of synergistic PEC-FL sensing platforms that combine the advantages of both is still in its early stages due to their relatively recent inception. Hydrogen sulfide (HS), possessing dual irritant and asphyxiating traits, poses challenges for environmental preservation and human health.

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Article Synopsis
  • The study focuses on a new nanopore sensor that uses a DNA walker and an autocatalytic reaction to detect DNA methyltransferases (MTases), important for understanding gene regulation and cancer.
  • The sensor operates by methylating and cleaving a hairpin DNA structure in the presence of Dam MTase, triggering a series of reactions that amplify the signal and produce numerous DNA nanowires.
  • This enhanced detection mechanism can identify extremely low levels of Dam MTase and can be adapted for M.SssI MTase, showcasing its potential in advanced biosensing applications.
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Innovative signal amplification and transduction play pivotal roles in bioanalysis. Herein, cascading CRISPR/Cas and the nanozyme are integrated with electronic amplification in an organic photoelectrochemical transistor (OPECT) to enable triple signal amplification, which is exemplified by the miRNA-triggered CRISPR/Cas13a system and polyoxometalate nanozyme for OPECT detection of miRNA-21. The CRISPR/Cas13a-enabled release of glucose oxidase could synergize with peroxidase-like SiW to induce catalytic precipitation on the photogate, inhibiting the interfacial mass transfer and thus the significant suppression of the channel current.

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The functionalization of metal-organic frameworks (MOFs) with organic small molecules by in situ postsynthetic modification has garnered considerable attention. However, the precise engineering of recognition sites using this method remains rarely explored in optically controlled bioelectronics. Herein, employing the Schiff base reaction to embed the small molecule (THBA) into a Zr-MOF, we fabricated a hydroxyl-rich MOF on the surface of titanium dioxide nanorod arrays (U6H@TiO NRs) to develop light-sensitive gate electrodes with tailored recognition capabilities.

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In conventional chromatographic ligand screening, underperforming ligands are often dismissed. However, this practice may inadvertently overlook potential opportunities. This study aims to investigate whether these underperforming ligands can be repurposed as valuable assets.

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In contrast to the conventional fluorescence enhancement resulting from the cessation of the photoinduced electron transfer effect upon capturing nitric oxide (NO) by o-phenylenediamine, we found an interesting fluorescence quench within small molecule fluorophores characterized by intramolecular hydrogen bonding. Herein, the integration of a push-pull electron system with intramolecular hydrogen bonding onto an ultra-small fluorophore was employed to fabricate a hydrogen bond-tuned single benzene core fluorescent probe with an exceptional fluorescence quantum yield of 26 %, denoted as HSC-1. By virtue of its small size and low molecular weight (mere 192 g/mol), it demonstrated superior solubility and biocompatibility.

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Al-rich (Si/Al = 4-6) Cu-SSZ-13 has been recognized as one of the potential catalysts to replace the commercial Cu-SSZ-13 (Si/Al = 10-12) towards ammonia-assisted selective catalytic reduction (NH-SCR). However, poor hydrothermal stability is a great obstacle for Al-rich zeolites to meet the catalytic applications containing water vapor. Herein, we demonstrate that the hydrothermal stability of Al-rich Cu-SSZ-13 can be dramatically enhanced Pr-ion modification.

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Reticular heterojunctions on the basis of metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) have sparked considerable interest in recent research endeavors, which nevertheless have seldom been studied in optoelectronic biosensing. In this work, its utilization for organic photoelectrochemical transistor (OPECT) detection of the important cancer biomarker of neuron-specific enolase (NSE) is reported. A MOF@COF@CdS quantum dots (QDs) heterojunction is rationally designed to serve as the photogating module against the polymeric channel.

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A facile route for exponential magnification of transconductance () in an organic photoelectrochemical transistor (OPECT) is still lacking. Herein, photoresponsive hydrogen-bonded organic frameworks (PR-HOFs) have been shown to be efficient for magnification in a typical poly(ethylene dioxythiophene):poly(styrenesulfonate) OPECT. Specifically, 450 nm light stimulation of 1,3,6,8-tetrakis (p-benzoic acid) pyrene (H4TBAPy)-based HOF could efficiently modulate the device characteristics, leading to the considerable magnification over 78 times from 0.

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Photocatalytic degradation is a promising method for controlling the increasing contamination of the water environment due to pharmacologically active compounds (PHACs). Herein, oxygen vacancy (OV)-modulated Z-scheme CuWO/CuBiO hybrid systems were fabricated thermal treatment by loading of CuWO nanoparticles with OVs on CuBiO surfaces. The synthesized CuWO/CuBiO hybrid samples exhibited an enhanced photodegradation ability to remove PHACs under visible-light irradiation.

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In this study, a polyethyleneimine (PEI)/Zr-functionalized nanofluidic sensing platform based on nonlinear hybridization chain reaction (NHCR) was developed for PNK activity assay. With the existence of PNK, the hairpin H was cleaved by λ exonuclease, liberating the initiator T-DNA. Then T-DNA triggered the nonlinear HCR in solution and the reaction products were absorbed onto the nanopore, which changed the surface charge of nanofluidic device and could be detected by current-voltage characteristic curves.

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The sensitive detection of neuron-specific enolase (NSE) as a biomarker for lung cancer at an early stage is critical but has long been a challenge. The emergence of polarity-switchable photoelectrochemical (PEC) bioanalysis has opened up new avenues for developing highly sensitive NSE sensors. In this study, we present such a biosensor depending on the bioinduced AgI transition on MOF-on-MOF-derived semiconductor heterojunctions.

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The accurate and ultrasensitive detection of multiple methyltransferases was in great request for clinical diagnosis and epigenetic therapy. Here, a novel fluorescence assay was proposed for ultrasensitive CpG methyltransferase (M.SssI) and DNA adenine methyltransferase (Dam) activity detection based on hyperbranched rolling circle amplification (HRCA) and DNA walkers.

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Metal selenides, as potential alternative candidates for sodium storage, have promising applicability due to their high theoretical specific capacity. However, their huge volume change and sluggish electrode kinetics during sodium ion uptake and release processes can result in insufficient cycling life and inferior rate performance, hindering their practical application. Herein, nitrogen (N)-doped carbon-confined cobalt selenide anchored on multiwalled carbon nanotube networks (denoted as CoSe@NC/MWCNTs) was designed and successfully built through a selenization process with ZIF-67 MOF as the template.

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DNA methylation is catalyzed by a family of DNA methyltransferases that play crucial roles in various biological processes. Therefore, an ultrasensitive methyltransferase assay is highly desirable in biomedical research and clinical diagnosis. However, conventional assays for the detection of DNA methyltransferase activity often involve radioactive labeling, costly equipment, and laborious operation.

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Precisely onsite monitoring of hypochlorite (ClO ) is of great significance to guide its rational use, reducing/avoiding its potential threat toward food safety and human health. Considering ClO could quench fluorescence of curcumin (CCM) by oxidizing the o-methoxyphenol of CCM into benzoquinone, a portable ratiometric fluorescence sensor integrated with smartphone was designed for realizing the visual point-of-care testing (POCT) of ClO . The amphiphilic phospholipid polymer was used as carrier to wrap curcumin, forming a novel liposome-encapsulated CCM, which provided a scaffold to bind with [Ru(bpy) ] through electrostatic interaction, thus assembling [Ru(bpy) ] -functionalized liposome-encapsulated CCM ([Ru(bpy) ] @CCM-NPs).

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The photoanode, photosystem II (PSII)/hierarchical inverse opal (IO) TiO, is coupled to the complementary photocathode, PbS quantum dots (QDs)/DNA probes, which is then integrated into a two-compartment photoelectrochemical (PEC) cell to achieve a self-powered system to enable photocathodic detection of microRNA-10b from HeLa cells. In such a system, all of the PSII catalytic products, i.e.

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Molybdenum disulfide (MoS2) has been regarded as a promising anode material in the field of sodium-ion batteries (SIBs), with the advantages of high theoretical capacity and large interlayer spacings. Unfortunately, its intrinsic poor electrical conductivity and large volume changes during the sodiation/desodiation reactions still limit its practical application. To deal with this shortcoming, we built MoS2 nanosheet/multiwalled carbon nanotube (denoted as MoS2-MSs/MWCNTs) composites with a three-dimensional (3D) micro-spherical structure, assembled in situ from MoS2 nanosheets.

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Cytoplasmic microviscosity (CPMV) plays essential roles in governing the diffusion-mediated cellular processes and has been recognized as a reliable indicator of the cellular response of many diseases and malfunctions. Current CPMV studies are exclusively established by probe-assisted optical methods, which nevertheless necessitate the complicated synthesis and delivery of optical probes into cells and thus the issues of biocompatibility and bio-orthogonality. Using twin nanopipettes integrated with a patch-clamp system, a practical electrochemical single-cell measurement is presented, which is capable of real-time and long-term CPMV detection without cell disruption.

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Emerging nanopipette tools have demonstrated substantial potential for advanced single-cell analysis, which plays vital roles from fundamental cellular biology to biomedical diagnostics. Highly recyclable nanopipettes with easy and quick regeneration are of special interest for precise and multiple measurements. However, existing recycle strategies are generally plagued by operational complexity and limited efficiency.

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Article Synopsis
  • The study explores a new method for photoelectrochemical (PEC) bioanalysis using nanopores that open and close depending on the target substance being analyzed.
  • It utilizes a setup with ascorbic acid in one chamber and a modified porous alumina membrane to control the movement of the acid, which affects the electrical response measured from a photoelectrode.
  • The method demonstrated effective detection of a specific protein (FABP) with strong sensitivity, selectivity, and potential for reuse, showing promise for broader applications in PEC analysis.
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The oxidative cross-coupling between the α-C(sp)-H bond of amide in DMAc and the inert -C(sp)-H bond of benzamides is achieved for the first time by nickel catalysis, with the assistance of 8-aminoquinolyl group in the presence of a silver oxidant. Notably, the selectivity of conversion can be perfectly controlled by modulating the oxidant additives, and the products from the coupling of the C(sp)-H bond adjacent to nitrogen of amides with benzamides are approached through the use of peroxide.

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In this paper, an ultrasensitive nanochannel sensor has been proposed for label-free Ochratoxin A (OTA) assay in combination with graphene oxide (GO) and catalyzed hairpin assembly (CHA). The high-performance sensor is segmented into two parts. One is composed of graphene oxide (GO) and DNA probes.

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Recently emerged liposomal photoelectrochemical (PEC) bioanalysis has brought new opportunities for biosensor development. This work presents the new concept of liposome-assisted enzymatic modulation of plasmonic photoelectrochemistry for PEC bioanalysis, which was exemplified by an Au nanoclusters (NCs)-sensitized nanoporous TiO nanotubes (Au NC@TiO NT) photoelectrode and an alkaline phosphatase (ALP)-loaded liposomal immunoassay of heart-type fatty acid binding protein in a 96-well plate. After sandwich immunorecognition and subsequent lysis treatment, enzymatically generated ascorbic acid by the released ALP was directed to reduce Au into Au nanoparticles using the Au NCs as seeds, leading to the in situ change of the photoelectrochemistry of the electrode and corresponding reduction of the photocurrent.

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Liposome-assisted photoelectrochemical (PEC) bioanalysis represents one of the latest frontiers in the arena of PEC bioanalysis. This work reports a general enzyme-amplified liposomal PEC bioanalysis protocol via the use of enzyme-loaded liposomes to boost the biocatalytic precipitation (BCP) effect. In the representative system, the horseradish peroxidase (HRP)-loaded liposome (HRPLL) and the Au nanoclusters (NCs)/Au nanoparticles (NPs)/TiO nanotubes (NTs) framework (AATF) were used as liposomal label and photoelectrode, respectively.

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