Rapid Detection of Broad-Spectrum Pathogenic Bacteria Based on Highly Sensitive Proton Response of the Nucleic Acid Amplification SPQC Platform.

Pathogenic bacteria significantly contribute to elevated morbidity and mortality rates, highlighting the urgent need for early and precise detection. Currently, there is a paucity of effective broad-spectrum methods for detecting pathogenic bacteria. We have developed an innovative proton-responsive series piezoelectric quartz crystal (PR-SPQC) platform for the broad-spectrum identification of pathogenic bacteria. This was achieved by retrieving and aligning sequences from the NCBI GenBank database to identify and validate 16S rRNA oligonucleotide sequences that are signatures of pathogenic bacteria but absent in humans or fungi. The hyperbranched rolling circle amplification, activated exclusively by the screened target, exponentially generates protons that are detected by SPQC through a 2D polyaniline (PANI) film. The PR-SPQC platform demonstrates broad-spectrum capabilities in detecting pathogenic bacteria, with a detection limit of 2 CFU/mL within 90 min. Clinical testing of blood samples yielded satisfactory results. With its advantages in miniaturization, cost efficiency, and suitability for point-of-care testing, PR-SPQC has the potential to be extensively used for the rapid identification of diverse pathogenic bacteria within clinical practice and public health sectors.

Ultrasensitive Detection of Tumor Suppressor Gene Methylation by Piezoelectric Sensing Based on Enrichment of Transcription Activator-Like Effectors.

The detection of DNA methylation at cytosine/guanine dinucleotide (CpG) islands in promoter regions of tumor suppressor genes has great potential for early cancer screening, diagnosis, and prognosis monitoring. Nevertheless, achieving accurate, sensitive, cost-effective, and quantitative detection of target methylated DNA remains challenging. Herein, we propose a novel piezoelectric sensor (series piezoelectric quartz crystal (SPQC)) based on transcription activator-like effectors (TALEs) for detecting DNA methylation of Ras association domain family 1 isoform A (RASSF1A) tumor suppressor genes (R-5mC). The sensor employs TALEs-Ni magnetic beads to specifically recognize and separate the R-5mC, thereby improving the detection selectivity. The TALEs-Ni magnetic beads-R-5mC complex is sheared by a nucleic acid enzyme (DNAzyme) to release the single-stranded DNA (ST). ST initiates a catalyzed hairpin assembly (CHA) reaction on the surface of the electrode, which in turn triggers the hybridization chain reaction (HCR) and silver staining for enhanced detection sensitivity. The strategy exhibits a linear response in the detection of R-5mC in the range of 1 fM to 1 nM with a detection limit of 0.79 fM. R-5mC as low as 0.01% can be detected, even in the presence of large numbers of unmethylated DNA. The detection of R-5mC in circulating cell-free DNA (cfDNA) derived from clinical plasma specimens of lung cancer patients yielded satisfactory results.

Fluoride-activated photothermal system for promoting bacteria-infected wound healing.

Although photothermal therapy (PTT) employing nanozymes has shown excellent antibacterial potential, excessive heating generally harms host cells and hinders recovery. Herein, we report an innovative technique for acquiring the programmed temperature by managing the catalytic activity of nanozymes. The photothermal system of CeO2 + F- + TMB can obtain precise photothermal temperature by adjusting the concentration of fluoride ions under near-infrared irradiation. At the optimized photothermal temperature, the photothermal system affords fine photothermal antibacterial treatment with high-efficiency antibacterial effects against Staphylococcus aureus and Escherichia coli in vitro. In vivo wound healing experiments confirm that the system can effectively promote fibroblast proliferation, angiogenesis and collagen deposition with remarkable wound healing efficiency. This strategy offers a novel design concept for creating a new generation of PTT and opens the way for the creation of alternative antibiotics.

Bi, Fe, and Ti ternary co-doped ZrO2 nanocomposites as a mass spectrometry matrix for the determination of bisphenol A and tetrabromobisphenol A in tea.

Bi, Fe, and Ti ternary co-doped ZrO2 (BFT-ZrO2) nanocomposites have been prepared by a sol-gel process and used as both adsorbent and matrix for the enrichment and determination of small molecules by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). The BFT-ZrO2 nanocomposites not only can selectively enrich a wide variety of low-mass toxic pollutants but can also be used as an excellent matrix to enhance the laser desorption/ionization efficiency with low background noise and uniform co-crystalline film. Low limits of detection (LODs) (0.1 pg mL-1 for bisphenol A (BPA), 2 pg mL-1 for tetrabromobisphenol A (TBBPA), 0.1 pg mL-1 for alizarin (AZ), 0.001 pg mL-1for bisphenol S (BPS), 0.01 pg mL-1 for indigo blue (ID), 0.01 pg mL-1 for pentachlorophenol (PCP), 100 pg mL-1 for estradiol (E2), 0.001 pg mL-1 for cetyltrimethylammonium bromide (CTAB), 0.1 pg mL-1 for crystal violet (CV), 1 pg mL-1 for malachite green (MG), 0.01 pg mL-1 for rhodamine B (RhB), and 0.01 pg mL-1 for perfluorooctane sulfonate (PFOS) were achieved. The relative standard deviations (RSDs) of shot-to-shot are 9.4-24% and of sample-to-sample 5.2-17%. The BFT-ZrO2 matrix was successfully applied to the determination of TBBPA and BPA in tea samples. This method shows a new strategy for determination of toxic compounds in tea. Graphical abstract.

Binding-Induced 3D-Bipedal DNA Walker for Cascade Signal Amplification Detection of Thrombin Combined with Catalytic Hairpin Assembly Strategy.

As an important biomarker, thrombin (TB) is a major player in thrombosis and hemostasis and has attracted increasing attention involving its determination. Herein a universal and ultrasensitive fluorescence biosensor based on a binding-induced 3D-bipedal DNA walker and catalytic hairpin assembly (CHA) strategy has been proposed for cascade signal amplification detection of thrombin. In this study, we designed two proximity probes (foot 1 and foot 2) which include a specific affinity ligand for TB binding and a Pb2+-dependent DNAzyme tail sequence. In the presence of TB, the simultaneous binding of TB to foot 1 (F1) and foot 2 (F2) via TB aptamer (TBA) brings the tail sequences into close proximity and the melting temperature for tail sequences and track DNA is increased, allowing the Pb2+-dependent DNAzyme to cleave the track DNA into two short fragments which have lower affinities for the DNAzyme and, finally, leading to the release of trigger DNA (T-DNA) for subsequent CHA reaction. In the meantime, the dissociated DNA walkers (F1 and F2) explore adjacent unwound track DNA, and the walking procedure is conducted. Unlike the conventional unipedal DNA walkers that anchor foot DNA and track DNA on the same sensing surface, the proposed 3D-bipedal DNA walking machine can not only increase the local concentration of track DNA but can also improve the walking efficiency and expand the range of the walkers to some extent due to the two free feet. Moreover, with the advantages of superior sensitivity and excellent specificity, this biosensing platform exhibits a huge potential in practical application in biomedical research and clinical diagnosis.

Reduced titania nanosheets as an effective visible-light germicide.

Two-dimensional reduced titania nanosheets (RTNs), synthesized by a solvothermal method, reveal significant visible light-activated germicidal activity. XRD, XPS, EPR, TEM and Raman show successful reduction of anatase TiO2, resulting in Ti3+ formation as well as an increase in the concentration of {001} facets. The RTNs possess a bandgap energy of approximately 2.86 eV, and demonstrate strong absorption over the visible spectrum. Under simulated solar light (λ = 320-780 nm, 70 mW cm-2) the RTNs are found to completely inactivate Escherichia coli bacteria within 1 h. Our study indicates the RTNs have significant potential for ameliorating antibiotic-resistant bacteria in clinical settings under ambient lighting conditions.

Cobalt-doped nanoporous carbon as SALDI-TOF-MS adsorbent and matrix for quantification of cetyltrimethylammonium bromide, Rhodamine B and Malachite Green at sub-ppt levels.

Cobalt-doped nanoporous carbon (Co-NPC) with dodecahedral shape was pyrolytically synthesized and applied as a sorbent and matrix for the enrichment and analysis of small molecules by surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS). Extremely low detection limits were accomplished for cetyltrimethylammonium bromide (1 fg·mL-1), and Rhodamine B (1 fg·mL-1) in water, and Malachite Green and its metabolite in fish blood and fish extracts (pg·mL-1 concentrations). Graphical abstract Schematic representation of cobalt-doped nanoporous carbons (Co-NPCs) applied as SALDI matrix for analysis of toxic contaminants in fish and receipt papers. The Co-NPCs have a high desorption/ionization efficiency and low limit of detection.

Preparation of Bi0.15Fe0.15TiO2 Nanocomposites for the Highly Selective Enrichment of Phosphopeptides.

Novel Bi0.15Fe0.15TiO2 nanocomposites (B0.15F0.15TNs) were synthesized for the first time by a modified sol-gel technology and successfully applied to selective extraction and enrichment of phosphopeptides from digested protein mixture solutions and real samples (tissue protein extract from human liver). The codoping of Bi and Fe into TiO2 results in a significant enhancement in both the enrichment efficiency and selectivity. Compared with the commercial available TiO2 extractant, the proposed B0.15F0.15TNs possess a lower detection limit (2 × 10-9 M) and higher selectivity at a low weight ratio of 1:1200 (phosphopeptides/nonphosphopeptides). Additionally, a total of 223 phosphorylation sites were identified from the human liver lysate after enrichment by the B0.15F0.15TNs. In addition, the synthesis of B0.15F0.15TNs is quite easy, of high yield, and inexpensive.

Photocatalytic Performance of a Nd-SiO2-TiO2 Nanocomposite for Degradation of Rhodamine B Dye Wastewater.

The photocatalytic performance of a novel Nd-SiO2-TiO2 nanocomposite catalyst prepared by a sol-gel method was examined in the degradation of Rhodamine B (RhB), a notorious organic compound present in dye wastewaters. The prepared samples were characterized by low-temperature N2 adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-vis diffuse reflectance spectroscopy (DRS). Fourier-transform infrared (FT-IR) spectroscopic analysis indicated the enhanced chemical bonding of O--Ti and O--Ti--O with introduction of Nd and SiO2 dopant species into TiO2. The Nd-SiO2-TiO2 nanocomposite was found to exhibit a much higher photo- catalytic activity toward the decomposition of RhB under both UV and visible light irradiation as compared to a commercial TiO2 photocatalyst. The photodegradation efficiency of RhB (5 mg/L) was greater than 93% under visible light irradiation after 90 min. Addition of SiO2 was shown to not only inhibit crystal growth and TiO2 anatase-to-rutile phase transformation, but also enhance the adsorption of organic compounds. Nd doping has been suggested for slowing down the radiative recombination of photo-generated electrons and holes in TiO2, extending the photocatalyst light response to the visible region. The synergetic effects between Nd-SiO2 and TiO2 are described; the prepared Nd-SiO2-TiO2 represents a noteworthy contribution to the study of pollutant degradation in dye wastewaters.

A PEDOT enhanced covalent organic framework (COF) fluorescent probe for in vivo detection and imaging of Fe3.

Simple and accurate in vivo monitoring of Fe3+ is essential for gaining a better understanding of its role in physiological and pathological processes. A novel fluorescent probe was synthesized via in situ solid-state polymerization of 3,4-ethylenedioxythiophene (PEDOT) in the pore channels of a covalent organic framework (COF). The PEDOT@COF fluorescent probe exhibited an absolute quantum yield (QY) 3 times higher than COF. In the presence of Fe3+ the PEDOT@COF 475 nm fluorescence emission, 365 nm excitation, is quenched within 180 s. Fluorescence quenching is linear with Fe3+ in the concentration range of 0-960 µM, with a detection limit of 0.82 µM. The fluorescence quenching mechanism was attributed to inner filter effect (IEF), photoinduced electron transfer (PET) and static quenching (SQE) between PEDOT@COF and Fe3+. A paper strip-based detector was designed to facilitate practical applicability, and the PEDOT@COF probe successfully applied to fluorescence imaging of Fe3+ levels in vivo. This work details a tool of great promise for enabling detailed investigations into the role of Fe3+ in physiological and pathological diseases.

Colorimetric sensing for the sensitive detection of UO22+via the phosphorylation functionalized mesoporous silica-based controlled release system.

In this study, we developed a simple and sensitive colorimetric sensing method for the detection of UO22+, which was built to release MB from the molybdenum disulfide with a phosphate group (MoS2-PO4) gated mesoporous silica nanoparticles functionalized phosphate group (MSN-PO4) with UO22+ chelating. In the presence of UO22+, MoS2-PO4 can be effectively adsorbed onto the surface of MSN-PO4 based on the coordination chemistry for strong affinity between the P-O bond and UO22+. The adsorbed MoS2-PO4 was then utilized as an ideal gate material to control the release of signal molecules (MB) entrapped within the pores of MSN-PO4, resulting in a detectable decrease in the absorption peak at 663 nm. This colorimetric sensing demonstrated the advantages of simplicity and easy manipulation and exhibited a linear response to the concentration of UO22+ within the range of 0.02-0.2 µM. The detection limit of UO22+ was determined to be 0.85 nM, which was lower than the limit (130 nmol L-1) set by the US Environmental Protection Agency. Furthermore, the proposed colorimetric sensing method has been utilized to determine UO22+ in samples of Xiangjiang River and tap water, and a high recovery rate was achieved. This method shows promising potential in preventing and controlling environmental pollution.

A supersensitive electrochemical sensor based on RCA amplification-assisted "silver chain"-linked gold interdigital electrodes and CRISPR/Cas9 for the detection of Staphylococcus aureus in food.

With the rising emphasis on food safety, technology to rapidly identify Staphylococcus aureus (S. aureus) is of great significance. Herein, we developed a novel electrochemical biosensor based on the CRISPR/Cas9 system and rolling circle amplification (RCA)-assisted "silver chain"-linked gold interdigital electrodes (Au-IDE). This sensor utilizes RCA to create DNA long chains that span the Au-IDE, and CRISPR/Cas9 as a recognition component to recognize capture/target dsDNA. Additionally, we used silver staining technology to improve detection sensitivity. Then, we detected S. aureus through impedance changes that occurred when the silver chain between the Au-IDE was connected or broke, with a limit of detection (LOD) of 7 CFU/mL and a detection time of 1.5 h. Lastly, we successfully employed this sensor to detect S. aureus in real food samples, making it a promising tool for food monitoring.

Novel Olefin-Linked Covalent Organic Framework with Multifunctional Group Modification for the Fluorescence/Smartphone Detection of Uranyl Ion.

Monitoring and purification of uranium contamination are of great importance for the rational utilization of uranium resources and maintaining the environment. In this work, an olefin-linked covalent organic framework (GC-TFPB) and its amidoxime-modified product (GC-TFPB-AO) are synthesized with 3-cyano-4,6-dimethyl-2-hydroxypyridine (GC) and 1,3,5-tris(4-formylphenyl) benzene (TFPB) by Knoevenagel condensation. GC-TFPB-AO results in specificity for rapid fluorescent/smartphone uranyl ion (UO22+) detection based on the synergistic effect of multifunctional groups (amidoxime, pyridine, and hydroxyl groups). GC-TFPB-AO features a rapid and highly sensitive detection and adsorption of UO22+ with a detection limit of 21.25 nM. In addition, it has a good recovery (100-111%) for fluorescence detection in real samples, demonstrating an excellent potential of predesigned olefin-linked fluorescent COFs in nuclear contaminated wastewater detection and removal.

Recent progress of UCNPs-MoS2 nanocomposites as a platform for biological applications.

Composite materials can take advantages of the functional benefits of multiple pure nanomaterials to a greater degree than single nanomaterials alone. The UCNPs-MoS2 composite is a nano-application platform that combines upconversion luminescence and photothermal properties. Upconversion nanoparticles (UCNPs) are inorganic nanomaterials with long-wavelength excitation and short-wavelength tunable emission capabilities, and are able to effectively convert near-infrared (NIR) light into visible light for increased photostability. However, UCNPs have a low capacity for absorbing visible light, whereas MoS2 shows better absorption in the ultraviolet and visible regions. By integrating the benefits of UCNPs and MoS2, UCNPs-MoS2 nanocomposites can convert NIR light with a higher depth of detection into visible light for application with MoS2 through fluorescence resonance energy transfer (FRET), which compensates for the issues of MoS2's low tissue penetration light-absorbing wavelengths and expands its potential biological applications. Therefore, starting from the construction of UCNPs-MoS2 nanoplatforms, herein, we review the research progress in biological applications, including biosensing, phototherapy, bioimaging, and targeted drug delivery. Additionally, the current challenges and future development trends of UCNPs-MoS2 nanocomposites for biological applications are also discussed.

Corrosion inhibition activity of a natural polysaccharide from Dysosma versipellis using tailor-made deep eutectic solvents.

In this work, a total of 18 types of choline chloride, betaine, and L-proline-based deep eutectic solvents (DESs) were synthesized to determine the extraction yield of a natural polysaccharide (PSA) from Dysosma versipellis using an ultrasound-assisted extraction method. Results indicate that the choline-oxalic acid-based DES has the best extraction yield for PSA due to the proper physical-chemical properties between PSA and DES. To evaluate the optimal extraction conditions, a response surface methodology was carried out. Under the optimal conditions, the extraction yield of PSA reaches 10.37 % (± 0.03 %), higher than the conventional extraction methods. Findings from FT-IR and NMR suggest that the extracted PSA belongs to a neutral polysaccharide with (1 â†’ 6)-linked α-d-glucopyranose in the main chain. Interestingly, results from various electrochemical measurements show the extracted PSA exhibits excellent corrosion inhibition performance for mild steel (MS) in a 0.5 M HCl solution, with 90.8 % of maximum corrosion inhibition efficiency at 210 mg L-1. SEM and XPS measurements reveal the formation of a protective layer on the MS surface. The adsorption behaviour of extracted PSA well obeys the Langmuir adsorption isotherm containing the chemisorption and physisorption. Additionally, theoretical calculations validate the experimental findings.

Efficient, specific and direct detection of double-stranded DNA targets using Cas12f1 nucleases and engineered guide RNAs.

To address the limitations of the CRISPR/Cas12f1 system in clinical diagnostics, which require the complex preparation of single-stranded DNA (ssDNA) or in vitro transcripts (RNA), we developed a fluorescent biosensor named PDTCTR (PAM-dependent dsDNA Target-activated Cas12f1 Trans Reporter). This innovative biosensor integrates Recombinase Polymerase Amplification (RPA) with the Cas12f_ge4.1 system, facilitating the direct detection of double-stranded DNA (dsDNA). PDTCTR represents a significant leap forward, exhibiting a detection sensitivity that is a hundredfold greater than the original Cas12f1 system. It demonstrates the capability to detect Mycoplasma pneumoniae (M. pneumoniae) and Hepatitis B virus (HBV) with excellent sensitivity of 10 copies per microliter (16.8 aM) and distinguishes single nucleotide variations (SNVs) with high precision, including the EGFR (L858R) mutations prevalent in non-small cell lung cancer (NSCLC). Clinical evaluations of PDTCTR have demonstrated its high sensitivity and specificity, with rates ranging from 93%-100% and 100%, respectively, highlighting its potential to revolutionize diagnostic approaches for infectious diseases and cancer-related SNVs.This research underscores the substantial advancements in CRISPR technology for clinical diagnostics and its promising future in early disease detection and personalized medicine.

Natural chitosan-based carbon dots as an eco-friendly and effective corrosion inhibitor for mild steel in HCl solution.

Polysaccharide chitosan and L-histidine were applied to synthesize chitosan-based carbon dots (CA-CDs) by a simple laser ablation method. After characterization of the CA-CDs by FT-IR, UV-vis, Raman, XRD, TEM, and XPS, the CA-CDs were introduced as an eco-friendly and high-performance corrosion inhibitor for mild steel (MS) in 1.0 M HCl solution. The inhibition action and mechanism of CA-CDs were determined by weight loss and electrochemical measurements, in combination with SEM, AFM, and XPS. The results show that CA-CDs as mixed-type inhibitors could effectively weaken the corrosion of MS in 1.0 M HCl solution, and their maximum inhibition efficiency reaches 97.4 % at 40 mg L-1. The adsorption behavior of CA-CDs well obeys the Langmuir adsorption isotherm containing both chemisorption and physisorption. The chemisorption mainly results from the multiple adsorption sites in the CA-CDs, and the physical adsorption is due to the blocking and barrier effect of CA-CD nanoparticles. Both adsorption behaviors were proposed to elucidate the corrosion inhibition mechanism of CA-CDs.

Target-triggered 'colorimetric-fluorescence' dual-signal sensing system based on the versatility of MnO2 nanosheets for rapid detection of uric acid.

A simple dual-signal assay that combined colorimetric and fluorometric strategy for uric acid (UA) rapid detection was designed based on the versatility of facile synthesized MnO2 nanosheet. The oxidization of 3,3',5,5'-tetramethylbenzidine (TMB) and the fluorescence quenching of quantum dots (QDs) occurred simultaneously in the presence of MnO2 nanosheet. UA could decompose MnO2 nanosheet into Mn2+, resulting in the fluorescence recovery of QDs, along with the fading of the blue color of ox TMB. Based on the principles above, the detection of UA could be realized by the change of the dual signals (colorimetric and fluorometric). The linear range of the colorimetric mode was 5-60 µmol L-1, and the limit of detection (LOD) was 2.65 µmol L-1; the linear range of the fluorescence mode was wide at 5-120 µmol L-1, and the LOD could be as low as 1.33 µmol L-1. The method was successfully used for analyzing UA levels in human serum samples, indicating that this new dual-signal method could be applied in clinical diagnosis.

Nanocomposite of Cu-TiO2-SiO2 with high photoactive performance for degradation of rhodamine B dye in aqueous wastewater.

The nanocomposite of Cu-TiO2-SiO2 photocatalyst have been prepared by a sol-gel method, which is used for the degradation of Rhodamine B (RB) as a probe that is notorious organic compound present in dyes wastewater. Morphological and structural characteristics of the Cu-TiO2-SiO2 nanocomposite were studied with low temperature N2 adsorption (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectroscopy (DRS). The Fourier transformed infrared spectroscopy (FT-IR) analysis shows the enhanced chemical bonding of O-Ti and O-Ti-O after the composition of Cu and SiO2 species into TiO2. It is found that the Cu-TiO2-SiO2 nanocomposite exhibits much higher photocatalytic activity under both UV light and visible light irradiation as compared with that over commercial titania (Degussa P25) toward the dyes wastewater containing RB. The photodegradation rate of RB (5 mg/L) can reach above 95.0% under sunlight after 3 h. The addition of SiO2 not only inhibites the crystal growth and anatase-to-rutile transformation of TiO2 nanocatalyst, but also enhances the adsorption of organic compounds. Cu-doping extends the light response to the visible region. Synergetic effects between Cu-SiO2 and TiO2 have been investigated, which provides a good way and material in the degradation field of dyes wastewater.

Engineering the Structural Defects of Spinel Oxide Nanoneedles by Doping of V for a Highly Efficient Oxygen Evolution Reaction.

Rational design of multi-structural defects in the transition-metal oxides is a very alluring and challenging strategy to significantly improve its oxygen evolution reaction (OER) performance. Herein, a simple and promising element doping approach is demonstrated to fabricate a poor-crystalline V-doping CuCo2O4 (V-CuCo2O4) nanoneedle with rich oxygen vacancies (Vo), partially amorphous phase, and Co2+ defects on the carbon fiber (CF) (V-CuCo2O4/CF). The results indicate that the V doping could further weaken the crystallinity of V-CuCo2O4, providing the thoroughfares for the convenience of electrolyte penetration and the exposure of active sites. Meanwhile, [CoO6] octahedron in the V-CuCo2O4 lattice is gravely distorted due to a strong electronic interaction between the doped V and Co atoms, creating more Co2+ active species. With the merits of these multiple structural defects, V-CuCo2O4/CF exhibits rich active sites, and its intrinsically electrocatalytic activity is significantly enhanced. The optimized V-CuCo2O4/CF electrocatalyst has a significantly enhanced OER activity with a required low overpotential of ∼204 and ∼246 mV at a current density of 100 and 300 mA cm-2, respectively, a small Tafel slope of 40.7 mV dec-1, and excellent stability in an alkaline medium. Furthermore, the results from the projected partial density of states calculation not only demonstrate that the 3-fol-coordinated Co near Vo bonded with Cu and V sites (Cu-Co(surf-Vo)-V) exhibits an enhanced electronic transfer activity but also reveal that the doped V could protect the Co sites from the deactivation by intermediates overbinding on the V sites. This work provides new insights into structure engineering of spinel phase copper cobaltite, resulting in significantly boosting electrocatalytic OER activity.