Elongation and Ligation-Mediated Differential Coding for Label-Free and Locus-Specific Analysis of 8-Oxo-7,8-dihydroguanine in DNA.

Oxidative DNA damage is closely associated with the occurrence of numerous human diseases and cancers. 8-Oxo-7,8-dihydroguanine (8-oxoG) is the most prevalent form of DNA damage, and it has become not only an oxidative stress biomarker but also a new epigenetic-like biomarker. However, few approaches are available for the locus-specific detection of 8-oxoG because of the low abundance of 8-oxoG damage in DNA and the limited sensitivity of existing assays. Herein, we demonstrate the elongation and ligation-mediated differential coding for label-free and locus-specific analysis of 8-oxoG in DNA. This assay is very simple without the involvement of any specific labeled probes, complicated steps, and large sample consumption. The utilization of Bsu DNA polymerase can specifically initiate a single-base extension reaction to incorporate dATP into the opposite position of 8-oxoG, endowing this assay with excellent selectivity. The introduction of cascade amplification reaction significantly enhances the sensitivity. The proposed method can monitor 8-oxoG with a limit of detection of 8.21 × 10-19 M (0.82 aM), and it can identify as low as 0.001% 8-oxoG damage from a complex mixture with excessive undamaged DNAs. This method can be further applied to measure 8-oxoG levels in the genomic DNA of human cells under diverse oxidative stress, holding prospect potential in the dynamic monitoring of critical 8-oxoG sites, early clinical diagnosis, and gene damage-related biomedical research.

RNA methylation-driven assembly of fluorescence-encoded nanostructures for sensitive detection of m6A modification writer METTL3/14 complex in human breast tissues.

N6-methyladenosine (m6A) is an ubiquitous post-transcriptional modification catalyzed by METTL3/14 complex in eukaryotic mRNAs. The abnormal METTL3/14 complex activity affects multiple steps of RNA metabolism and may induce various diseases. Herein, we demonstrate the RNA methylation-driven assembly of fluorescence-encoded nanostructures for sensitive detection of m6A modification writer METTL3/14 complex in human breast tissues. METTL3/14 complex can catalyze the methylation of RNA probe to prevent it from being cleaved by MazF. The intact RNA probe is recognized by the magnetic bead (MB)-capture probe conjugates to induce duplex-specific nuclease (DSN)-assisted cyclic digestion, exposing numerous shorter ssDNAs with 3'-OH end. The shorter ssDNAs on the MB surface can act as the primers to initiate terminal deoxynucleotidyl transferase (TdT)-enhanced tyramide signal amplification (TSA), forming the Cy5 fluorescence-encoded nanostructures. After magnetic separation, the Cy5 fluorescence-encoded nanostructures are digested by DNase I to release abundant Cy5 fluorophores that can be simply quantified by fluorescence measurement. This assay achieves good specificity and high sensitivity with a detection limit of 58.8 aM, and it can screen METTL3/14 complex inhibitors and quantify METTL3/14 complex activity at the single-cell level. Furthermore, this assay can differentiate the METTL3/14 complex level in breast cancer patient tissues and healthy volunteer tissues.

Deamination-triggered exponential signal amplification for chemiluminescent detection of cytosine deaminase at the single-cell level.

We construct a sensitive chemiluminescent biosensor for sensitive detection of cytosine deaminase APOBEC3A based on deamination-triggered exponential signal amplification. This biosensor displays good specificity and high sensitivity, and it can screen APOBEC3A inhibitors and measure endogenous APOBEC3A at the single-cell level, with prospective applications in disease diagnostics and therapy.

Construction of Multiple DNAzymes Driven by Single Base Elongation and Ligation for Single-Molecule Monitoring of FTO in Cancer Tissues.

Fat mass and obesity-associated proteins (FTO) play an essential role in the reversible regulation of N6-methyladenosine (m6A) epigenetic modification, and the overexpression of FTO is closely associated with the occurrence of diverse human diseases (e.g., obesity and cancers). Herein, we demonstrate the construction of multiple DNAzymes driven by single base elongation and ligation for the single-molecule monitoring of FTO in cancer tissues. When target FTO is present, the m6A-RNA is specifically demethylated and subsequently acts as a primer to combine with the padlock probe, initiating single-base elongation and ligation reaction to generate a closed template probe. Upon the addition of phi29 DNA polymerase, a rolling circle amplification (RCA) reaction is initiated to produce large numbers of Mg2+-dependent DNAzyme repeats. Subsequently, the DNAzymes cyclically digest the signal probes, liberating numerous Cy5 molecules that can be precisely counted by single-molecule imaging. Taking advantage of the sequence specificity of the polymerase/ligase-mediated gap-filling and ligation as well as the high amplification efficiency of RCA, this biosensor shows excellent specificity and high sensitivity with a detection limit of 5.96 × 10-16 M. It can be applied to screen FTO inhibitors and quantify FTO activity at the single-cell level. Moreover, the proposed strategy can accurately distinguish the FTO expression level in tissues of healthy individuals and breast cancer patients, providing a new platform for drug discovery, m6A modification-related research, and clinical diagnostics.

Ultrasonic/electrical dual stimulation response nanocomposite bioelectret for controlled precision drug release.

Electret materials have attracted extensive attention because of their permanent polarization and electrostatic effect. However, it is one of problem that needs to be solved in biological application to manipulate the change of surface charge of electret by external stimulation. In this work, a drug-loaded electret with flexibility and no cytotoxicity was prepared under relatively mild conditions. The electret can release the charge through stress change and ultrasonic stimulation, and the drug release can be accurately controlled with the help of ultrasonic and electric double stimulation response. Here, the dipoles like particles of carnauba wax nanoparticles (nCW) are fixed in the matrix based on the interpenetrating polymer network structure, and "frozen" oriented dipolar particles that are treated by thermal polarization and cooled at high field strength. Subsequently, the charge density of the prepared composite electret can reach 101.1 â€‹nC/m2 at the initial stage of polarization and 21.1 â€‹nC/m2 after 3 weeks. In addition, the stimulated change of electret surface charge flow under cyclic tensile stress and cyclic compressive stress can generate a current of 0.187 â€‹nA and 0.105 â€‹nA at most. The ultrasonic stimulation results show that when the ultrasonic emission power was 90% (Pmax â€‹= â€‹1200 â€‹W), the current of 0.472 â€‹nA can be generated. Finally, the drug release characteristics and biocompatibility of the nCW composite electret containing curcumin were tested. The results showed that it not only had the ability to accurately control the release by ultrasound, but also triggered the electrical effect of the material. The prepared drug loaded composite bioelectret provides a new way for the construction, design and testing of the bioelectret. Its ultrasonic and electrical double stimulation response can be accurately controlled and released as required, and it has broad application prospects.

Controllable assembly of dendritic DNA nanostructures for ultrasensitive detection of METTL3-METTL14 m6A methyltransferase activity in cancer cells and human breast tissues.

N6-Methyladenosine (m6A) is a reversible chemical modification in eukaryotic messenger RNAs and long noncoding RNAs. The aberrant expression of RNA methyltransferase METTL3-METTL14 complex may change the m6A methylation level and cause multiple diseases including cancers. The conventional METTL3-METTL14 assays commonly suffer from time-consuming procedures and poor sensitivity. Herein, we develop a controllable amplification machinery based on MazF-activated terminal deoxynucleotidyl transferase (TdT)-assisted dendritic DNA structure assembly for ultrasensitive detection of METTL3-METTL14 complex activity in cancer cells and breast tissues. The presence of METTL3-METTL14 complex catalyzes the formation of m6A in detection probe, effectively preventing the cleavage of methylated detection probes by MazF. The methylated detection probes with 3'-OH termini can function as the primers for template-free polymerization catalyzed by TdT on magnetic beads (MBs), producing long chains of poly-thymidine (poly-T) sequences. Then poly-T sequences hybridize with signal probes that contain poly-adenine (poly-A) sequence, inducing TdT-mediated polymerization and the subsequent hybridization with more poly-A signal probes for generating dendritic DNA nanostructures assembled on MBs. After magnetic separation and elevated temperature treatment, the signal probes are disassembled from MBs to generate a high fluorescence signal. This method possesses excellent specificity and high sensitivity with a limit of detection (LOD) of 2.61 × 10-15 M, and it can accurately quantify cellular METTL3-METTL14 complex at single-cell level. Furthermore, it can screen inhibitors, evaluate kinetic parameters, and discriminate breast cancer tissues from normal tissues.

CRISPR/Cas-Based MicroRNA Biosensors.

As important post-transcriptional regulators, microRNAs (miRNAs) play irreplaceable roles in diverse cellular functions. Dysregulated miRNA expression is implicated in various diseases including cancers, and thus miRNAs have become the valuable biomarkers for disease monitoring. Recently, clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas) system has shown great promise for the development of next-generation biosensors because of its precise localization capability, good fidelity, and high cleavage activity. Herein, we review recent advance in development of CRISPR/Cas-based biosensors for miRNA detection. We summarize the principles, features, and performance of these miRNA biosensors, and further highlight the remaining challenges and future directions.

Enzymatic DNA repairing amplification-powered construction of an Au nanoparticle-based nanosensor for single-molecule monitoring of cytosine deaminase activity in cancer cells.

APOBEC3A (A3A) is a cytidine deaminase with critical roles in molecular diagnostics. Herein, we demonstrate the enzymatic DNA repairing amplification-powered construction of an Au nanoparticle-based nanosensor for single-molecule monitoring of A3A activity in cancer cells. Target A3A can convert cytosine (C) in substrate probe to uracil (U), and then the template binds with substrate probe to form a dsDNA containing U/A base pairs. Uracil DNA glycosylase (UDG) excises the U base to produce an apurinic/apyrimidinic (AP) site that can be cleaved by apurinic/apyrimidic endonuclease 1 (APE1) to obtain the substrate fragment with 3'-OH end. Subsequently, the substrate fragment initiates cyclic enzymatic repairing amplification (ERA), releasing trigger-1 and trigger-2. The resultant trigger-1 can act as the primer to induce multiple cycles of cyclic ERA, producing numerous trigger-1 and trigger-2. The hybridization of trigger-2 with signal probe forms the dsDNA duplexes with an AP site, inducing the cyclic cleavage of signal probes by APE1 to release abundant Cy5 molecules from the AuNPs. Released Cy5 molecules can be easily quantified by single-molecule imaging. This nanosensor allows for specific and sensitive detection of A3A activity with a detection limit of 0.855 aM, and it can further measure kinetic parameters, screen inhibitors, and quantify endogenous A3A activity at the single-cell level, with prospect application in disease diagnostics and therapy.

Activatable Self-Dissociation of Watson-Crick Structures with Fluorescent Nucleotides for Sensing Multiple Human Glycosylases at Single-Cell Level.

Nucleobase oxidation and alkylation can destroy Watson-Crick base-pairing to challenge the genomic integrity. Human 8-oxoguanine glycosylase 1 (hOGG1) and alkyladenine glycosylase (hAAG) are evolved to counter these two cytotoxic lesions through base-excision repair, and their deregulations are implicated with multifactorial diseases and cancers. Herein, we demonstrate activatable self-dissociation of Watson-Crick structures with fluorescent nucleotides for sensing multiple human glycosylases at single-cell level. The presence of hOGG1 and hAAG catalyzes 8-oxoG and deoxyinosine removal in functional probe 1 to release two trigger probes (1 and 2). Then, trigger probes hybridize with functional probe 2 to activate the autocatalytic degradation of functional probes 2 (Cycle I) and 3 (Cycle II), replicating abundant trigger probes (1-4) and releasing two fluorophores (2-aminopurine (2-AP) and pyrrolo-dC (P-dC)). New trigger probes (1, 2) and (3, 4), in turn, hybridize with free functional probes 2 and 3, repeating Cycles I and II turnovers. Through multicycle self-dissociation of Watson-Crick structures, 2-AP and P-dC are exponentially accumulated for the simultaneous quantification of hOGG1 and hAAG. This nanodevice exhibits high sensitivity with a detection limit of 2.9 × 10-3 U/mL for hOOG1 and 1.5 × 10-3 U/mL for hAAG, and it can measure enzymatic kinetics, identify potential inhibitors, discriminate glycosylases between cancer and normal cell lines, and even quantify glycosylase activities in a single HeLa cell. Moreover, this assay may be rapidly and isothermally performed in one tube with only one tool enzyme in a quencher-free manner, promising a simple and powerful platform for multiple human glycosylase detection.

Entropy-Driven Self-Assembly of Single Quantum Dot Sensor for Catalytic Imaging of Telomerase in Living Cells.

Telomerase is a highly valuable cancer diagnosis biomarker and a promising cancer therapy target. So far, most telomerase assays are limited by the involvement of tedious procedures, multiple enzymes, and complicated reaction schemes. Sensitive monitoring of low-abundant telomerase in living cells remains a challenge. Herein, we demonstrate an entropy-driven catalytic assembly of quantum dot (QD) sensors for accurate detection and imaging of telomerase activity in living cells. In this sensor, target telomerase specifically catalyzes extension of telomerase primer, and the extended primer subsequently acts as a catalyst to continuously initiate entropy-driven catalytic reaction, generating a large number of fluorophore- and biotin-labeled DNAs that can be self-assembled on the QD surface to induce an efficient Föster resonance energy transfer signal. The proposed sensor requires a single step for both recognition and amplification of the telomerase signal, eliminating the use of either protein enzymes or laborious procedures. Taking advantage of the inherent superiority of single-molecule fluorescence detection and high amplification efficiency of the entropy-driven reaction, this sensor demonstrates single-cell sensitivity for the in vitro assay. Moreover, it is capable of screening the telomerase inhibitor, discriminating different tumor cells from normal ones, and even real-time imaging telomerase in living cells, providing a novel platform for telomerase-associated cancer diagnosis and drug screening.

Construction of a dual-functional dumbbell probe-based fluorescent biosensor for cascade amplification detection of miRNAs in lung cancer cells and tissues.

We develop a dual-functional dumbbell probe-based fluorescent biosensor for cascade amplification detection of miRNAs in lung cancer cells and tissues by integrating a primer exchange reaction (PER) with the CRISPR-Cas12a system. This biosensor can absolutely quantify the miR-486-5p expression in different lung cancer cells and distinguish non-small cell lung cancer (NSCLC) patients from healthy individuals, holding great potential in biomedical research and clinical diagnosis.

Construction of an APE1-Mediated Cascade Signal Amplification Platform for Homogeneously Sensitive and Rapid Measurement of DNA Methyltransferase in Escherichia coli Cells.

DNA methylation is an essential genomic epigenetic behavior in both eukaryotes and prokaryotes. Deregulation of DNA methyltransferase (Dam MTase) can change the DNA methylation level and cause various diseases. Herein, we develop an apurinic/apyrimidinic endonuclease 1 (APE1)-mediated cascade signal amplification platform for homogeneously sensitive and rapid measurement of Dam MTase in Escherichia coli cells. This assay involves a partial double-stranded DNA (dsDNA) substrate and two hairpin signal probes (HP1 and HP2) that are modified with Cy5 and BHQ2 at two ends, respectively. When Dam MTase is present, it methylates the dsDNA substrate, and subsequently, endonuclease DpnI cleaves the methylated substrate, yielding trigger probe 1. Hybridization of trigger probe 1 with HP1 forms a partial dsDNA containing an apurinic/apyrimidinic (AP) site, which is cleaved by APE1 to induce the cyclic cleavage of HP1 and the production of abundant trigger probe 2. Subsequent hybridization of trigger probe 2 with HP2 forms a partial dsDNA with an AP site, inducing the cyclic cleavage of HP2 by APE1. Consequently, cyclic cleavage of HP1 and HP2 induces the generation of abundant Cy5 molecules, which are easily measured by single-molecule imaging. This assay can be performed homogeneously and rapidly within 2 h, which is the shortest among the reported amplification-based assays. Moreover, it exhibits good selectivity and high sensitivity, and it can discriminate Dam MTase from other enzymes and screen inhibitors. Importantly, it can accurately measure the Dam MTase activity in serum and E. coli cells, with promising applications in clinical diagnosis and drug discovery.

Mismatched fluorescent probes with an enhanced strand displacement reaction rate for intracellular long noncoding RNA imaging.

We design mismatched fluorescent probes to directly monitor the long noncoding RNA (lncRNA) in living cells. The introduction of mismatched bases in the fluorescent probe greatly enhances the strand displacement reaction rate toward the target lncRNA. These mismatched probes can monitor the intracellular lncRNA expression level in various cell lines and discriminate cancer cells from normal cells, holding great potential in fundamental biomedical research and clinical disease diagnosis.

Construction of a Structure-Switchable Toehold Dumbbell Probe for Sensitive and Label-Free Measurement of MicroRNA in Cancer Cells and Tissues.

MicroRNAs (miRNAs) play multiple crucial roles in post-transcriptional regulating gene expression, and the abnormal expression may induce various human diseases. Herein, we demonstrate the construction of a structure-switchable toehold dumbbell probe for sensitive and label-free measurement of microRNA in cancer cells and tissues on the basis of integrating exponential-rolling circle amplification (EXP-RCA) with linear-rolling circle amplification (LRCA). We designed a structure-switchable toehold dumbbell probe with annular and symmetric structure whose either side can hybridize with target miRNA to initiate EXP-RCA, greatly improving the detection sensitivity. Moreover, the dumbbell probe is designed with an appropriate standard free energy (G), and it cannot be activated by mismatched miRNAs, endowing this assay with good specificity. When target miRNA is present, it interacts with the dumbbell probe to activate EXP-RCA via toehold-mediated stand displacement, generating abundant triggers. The resulting triggers and target miRNA can function as primers to initiate LRCA, producing abundant long tandem repeats that can generate a distinct fluorescence signal using SYBR Gold as the indicator. This assay can be carried out homogeneously and isothermally without the requirement for either sophisticated modification/separation steps or any extra primers. It displays ultrahigh sensitivity with a limit of detection of 8.45 × 10-17 M and excellent specificity, and it can differentiate let-7a from its homologous analogues. Moreover, this method can accurately quantify let-7a expression at a single-cell level and can even distinguish the let-7a expression between non-small cell lung cancer patient tissues and healthy person tissues.

Simultaneous single-molecule detection of the acetyltransferase and crotonyltransferase activities of histone acetylation writer p300.

We demonstrate for the first time the simultaneous measurement of the acetyltransferase (HAT) and crotonyltransferase (HCT) activities of histone acetylation writer p300 by integrating antibody-based fluorescence labeling with single molecule detection. This methods exhibits good specificity and high sensitivity. Moreover, it can accurately evaluate the kinetic parameters of both the HAT and HCT activities of p300 and screen inhibitors.

Construction of a damage site-specific fluorescent biosensor for single-molecule detection of DNA damage.

The 8-oxoguanine (8-oxoG) represents the most common DNA damage type, and it has been regarded as the oxidative stress biomarker, but the reported 8-oxoguanine assays are limited by poor specificity and low sensitivity. Herein, we demonstrate the construction of damage site-specific fluorescent biosensor for 8-oxoG assay by integrating single-molecule detection with hyperbranched signal amplification. In this assay, the 8-oxoG damages in DNA can generate free 3' OH with the assistance of formamidopyrimidine DNA glycosylase (Fpg) and polynucleotide kinase (PNK), which subsequently triggers the incorporation of abundant Cy5-labeled dUTPs via terminal deoxynucleotidyl transferase (TDT)-mediated site-specific hyperbranched nucleic acid amplification. After digestion of amplification products with nuclease treatment, abundant mononucleotide Cy5-dUTPs are produced, which will be easily monitored via single-molecule imaging and detection. The introduction of hyperbranched nucleic acid amplification and single-molecule detection can greatly improve the sensitivity to achieve a detection limit of 7.62 × 10-18 M. This biosensor is highly specific with the capability of discriminating 0.001% 8-oxoG target from the DNA mixture. Moreover, it can be applied for quantitative detection of 8-oxoG damage in genomic DNAs with a detection limit of 0.0017 ng, and even accurately quantifies the absolute number (7025 - 8506) of 8-oxoG damage base in single HeLa cell treated with 150 µM H2O2. Importantly, this biosensor can measure the 8-oxoG damage level in different cancer cell lines, facilitating the oxidative damage-associated biomedical researches and clinical diagnosis.

3'-Terminal Repair-Powered Dendritic Nanoassembly of Polyadenine Molecular Beacons for One-Step Quantification of Alkaline Phosphatase in Human Serum.

Alkaline phosphatase (ALP) is an important hydrolase with crucial roles in biological processes, and the dysregulation of ALP may cause various human diseases. The conventional ALP assays usually involve cumbersome procedures with poor sensitivity. Herein, taking advantage of intrinsic superiorities of molecular beacons (MBs) and unique features of terminal deoxynucleotidyl transferase (TdT), we demonstrate for the first time the 3'-terminal repair-powered dendritic nanoassembly of polyadenine (A) MBs for one-step quantification of ALP in human serum. When ALP is present, it catalyzes 3'-terminal dephosphorylation of poly-A MBs to induce TdT-mediated template-free polymerization, generating long chains of polythymidine (T) sequences. The long poly-T chains can function as the anchoring templates to hybridize with many poly-A MBs, leading to the unfolding of loop structures and the dissociation of FAM/BHQ1 pairs (the 1st amplification stage). Subsequently, all 3'-hydroxylated poly-A MBs can be extended with the assistance of TdT to generate the branched long poly-T chains, leading to the hybridization of more poly-A MBs and the dissociation of more FAM/BHQ1 pairs (the 2nd amplification stage). Through multiple rounds of extension, assembly, and activation of poly-A MBs, dendritic DNA nanostructures are automatically formed, resulting in the dissociation of abundant fluorophores from the FAM/BHQ1 pairs to generate an exponentially amplified fluorescence signal (the nth amplification stage). This strategy possesses high sensitivity and excellent specificity, and the detection limit can reach 1 cell. Moreover, it can evaluate kinetic parameters, screen inhibitors, estimate cellular inhibition effects, and measure ALP in human serums.

An antibody-like peptidic network for anti-angiogenesis.

Different from chemical (small molecular inhibitor) and biological (monoclonal antibody) drugs, herein, based on angiogenesis-related neuropilin-1 (NRP-1), we develop a biomimetic superstructure drug, i.e. an antibody-like peptidic network (ALPN) to achieve the high-efficient treatment of choroidal neovascularization (CNV). The ALPN in nanoparticulated formulation (ALPN-NPS) can bind NRP-1 through targeting unit and form fibrous peptidic networks trapping NRP-1 on the surface of endothelial cells (ECs), leading to anti-angiogenesis. The ALPN shows high-efficacy against angiogenesis in CNV rat model ascribed to the superstructure-enhanced binding and blockage of NRP-1. The very low dose of ALPN (0.263 µg/Kg) exhibits similar anti-angiogenesis effect comparing with monoclonal antibody bevacizumab (23.5 µg/Kg), which shows potential advantages over traditional monoclonal antibodies.

Simultaneous Enzyme-Free Detection of Multiple Long Noncoding RNAs in Cancer Cells at Single-Molecule/Particle Level.

Aberrant change in long noncoding RNA (lncRNA) is associated with various diseases and cancers. So far, simultaneous detection of lncRNAs has remained a great challenge due to their large size and extensive secondary structure. Herein, we develop an enzyme-free single-molecule/particle detection method for simultaneous detection of multiple lncRNAs in cancer cells based on target-catalyzed strand displacement. We designed the magnetic bead-capture probe-multiple Cy5/Cy3-modified reporter unit complexes to isolate and identify lncRNA MALAT1 and lncRNA HOTAIR. The target-catalyzed strand displacement reactions lead to the release of Cy5 and Cy3 fluorescent molecules from the complexes, which can be subsequently quantified by single-molecule/particle detection. The dual-targetability, good selectivity and high sensitivity of this method enables simultaneous detection of multiple lncRNAs in even single cancer cell. Importantly, this method can discriminate cancer cells from normal cells and has significant advantages in the simple sequence design and in being free of enzymes, holding great potential in living cell imaging and early clinical diagnosis.

Controllable synthesis of CoFe2Se4/NiCo2Se4 hybrid nanotubes with heterointerfaces and improved oxygen evolution reaction performance.

The rational construction of heterointerfaces in hollow nanohybrids is considered as a promising and challenging approach for enhancing their electrocatalytic performance. Herein, we demonstrate the synthesis of CoFe2Se4/NiCo2Se4 hybrid nanotubes (CFSe/NCSe HNTs) with open ends and abundant heterointerfaces. The CFSe/NCSe HNT hybrid nanotubes are obtained by using NiCo2-aspartic acid nanofibres (NiCo-Asp NFs) as the templates which can be converted to the CFSe/NCSe HNTs via proton etching, three metal coprecipitation, Kirkendall effect and anion-exchange reaction. The CFSe/NCSe HNTs may function as the oxygen evolution reaction (OER) electrocatalysts, and they exhibit a low overpotential of 224 mV at a current density of 10 mA cm-2 and outstanding stability with only 1.4% current density change even after 15 h, superior to those of the reported single-component counterparts. The obtained density of states and differential charge density confirm the existence of a heterointerface which can induce the accumulation of electrons at the interface of CFSe-NCSe and consequently increase the carrier density and electrical conductivity of the CFSe/NCSe HNTs. This research provides a new avenue for the fabrication of hollow nanohybrids with heterointerfaces.