Loading Au Nanoparticles Research Articles

Alkaline-Assisted Excessive Impregnation for Enhancing Au Nanoparticle Loading on the TS-1 Zeolite.

Direct epoxidation of propylene (C3H6) with hydrogen (H2) and oxygen (O2) over the Au/TS-1 catalyst is known as the "Holy Grail" reaction for propylene oxide (PO) synthesis. However, Au nanoparticle loading on TS-1 was limited by traditional deposition precipitation, impregnation and could not achieve ideal catalytic results. In this report, alkaline-assisted excessive impregnation helped to remove Cl- from the Au impregnation precursor, improve the loading efficiency of Au nanoparticles and overcome the abnormal growth of nanograins. Better hydrophobicity, surface acidity and an oxygen-containing free radical environment helped Au/TS-1-AEI achieve much better C3H6 conversion (8.0%), PO selectivity (96.7%) and stability (>100 h).

A dual-mode colorimetric/photothermal lateral flow biosensor based on Au/Ti3C2TX for HIV-DNA detection.

Traditional lateral flow biosensors (LFBs), which utilize colorimetric signals as output, possess the virtues of simplicity and rapidity. However, it also suffers from insufficient sensitivity and limited reliability. It is well known that the results of LFBs can be false positive, and it is difficult to perform accurate quantification under low-abundance targets. In recent years, researchers have continued to apply new nanomaterials to LFBs to obtain more sensitive detection performance and multiple signal output modes. Herein, taking advantage of its excellent color intensity and photothermal properties, we synthesized a dual-functional Au/Ti3C2TX nanocomposite material by loading Au nanoparticles (Au NPs) on Ti3C2TX via the one-step self-reduction method, in which process Ti3C2TX acted as both reducing agent and carrier at the same time. Based on the prepared material, a colorimetric/photothermal dual-mode LFB was constructed for the detection of human immunodeficiency virus (HIV) DNA. In this work, the Au/Ti3C2TX nanocomposite served as a dual-signal label on the LFB platform for the first time. As a colorimetric label, Au/Ti3C2TX achieved signal amplification owing to abundant Au NPs loaded on Ti3C2TX. When playing the role of a photothermal label, the excellent photothermal effect of Au/Ti3C2TX contributed to a low limit of detection down to 0.01nM target in human serum. Au/Ti3C2TX served as a dual-signal label on the LFB platform for the first time and showed extremely dependable analytical performance. Furthermore, this work offered a novel versatile dual-mode point-of-care testing platform in the fields of food safety, clinical diagnosis, and environmental monitoring.

Controllable Synthesis of Amino-Functionalized Silica Particles via Co-condensation of Tetraethoxysilane and (3-Aminopropyl)triethoxysilane.

Amino-functionalized silica has attracted a great deal of interest due to its high surface reactivity and potential for diverse applications across various fields. While the classical co-condensation method is commonly used to synthesize amino-functionalized silica particles, the mechanism of the reaction between (3-aminopropyl)triethoxysilane (APTES) and tetraethoxysilane under different conditions remains unclear, leading to unexpected self-nucleation or cross-linking between silica particles and consequently hindering rational control over the extent of functionalization. To address this issue, we systematically explored the co-condensation growth mechanism of amino-functionalized silica particles in the Stöber method by investigating the effects of APTES concentration and water content on the hydrolysis and condensation of silanes. The experimental results revealed that APTES could decrease the rate of hydrolysis/condensation, while the moderate water content promoted both the rate of hydrolysis/condensation and the overall quality of the silica particles. Consequently, we successfully demonstrated the rational synthesis of amino-functionalized silica particles with diameters ranging from 213 to 670 nm and a nitrogen content of ≤2.8 wt %. The relationship between the APTES concentration and particle properties exhibited a biphasic trend. At low APTES concentrations (≤2.0 mM), the particle size remained stable while the isoelectric point increased rapidly. Further increasing the APTES concentration from 2.0 to 100.0 mM induced a decrease in particle size due to APTES's inhibitory effect on silica growth, with nitrogen content continuing to increase even after the isoelectric point remained unchanged. These silica particles, featuring varying surface amino group densities, were utilized as matrices for loading Au nanoparticles. The resulting functionalized particles exhibited distinctive catalytic ability in the reduction of 4-nitroaniline, demonstrating significant potential for applications across various fields.

Construction of Au nanoparticles decorated on ZnFe2O4@ZnIn2S4 core-shell structure to enhance photocatalytic hydrogen production

Developing effective photocatalysts for water splitting is essential to generating H2 energy sources. Herein, a novel ZnFe2O4@ZnIn2S4/Au ternary composite (abbreviated as ZFO@ZIS/Au) was successfully designed and fabricated by loading Au nanoparticles on the ZFO@ZIS surfaces for effective photocatalytic H2 generation for the first time. Attributed to the synergistic effect of the traditional II-type heterojunction charge transfer and Au nanoparticles as co-catalysts, the ZFO@ZIS/Au heterojunction generated greater amounts of hydrogen under visible light irradiation. The ZFO-7 %@ZIS/Au-2 catalyst displayed the highest H2 production rate of 1145.38 μmol∙g−1∙h−1, which was almost 3.87 times more than the ZIS value. Furthermore, several characterization techniques were performed to investigate the catalysts and evaluate the catalyst's photocatalytic activity when exposed to visible light. Lastly, a detailed discussion of the corresponding photocatalytic H2 production process of the as-prepared ZFO@ZIS/Au heterojunction was provided. The distinctive research might offer a potential approach for modifying zinc ferrate for photocatalytic hydrogen production.

Releasing Au Electrons to Mo Site for Weakened Mo─H Bond of Mo2C MXene Cocatalyst Toward Improved Photocatalytic H2 Production.

Mo2C MXene (Mo2CTx) is one of the most promising noble-metal-free cocatalysts for photocatalytic H2 production because of its excellent electron transport capacity and abundant Mo sites. However, Mo2CTx typically exhibits a strong Mo─Hads bond, resulting in that the produced H2 difficultly desorbs from the Mo surface for the limited activity. To effectively weaken the Mo─Hads bond, in this paper, a regulation strategy of electron donor Au releasing electrons to the d-orbitals of Mo sites in Mo2CTx is proposed. Herein, the Mo2CTx-Au/CdS photocatalysts are prepared through a two-step process, including the initial loading of Au nanoparticles on the Mo2CTx surface and the subsequent in situ growth of CdS onto the Mo2CTx-Au surface. Photocatalytic measurements indicate that the maximal H2-production rate of Mo2CTx-Au/CdS reaches up to 2799.44µmol g-1h-1, which is 30.99 and 3.60 times higher than that of CdS and Mo2CTx/CdS, respectively. Experimental and theoretical data corroborate that metallic Au can transfer free electrons to Mo2CTx to generate electron-enriched Moδ- sites, thus causing the increased antibonding-orbital occupancy state and the weakened Mo─Hads bond for the boosted H2-production efficiency. This research provides a promising approach for designing Mo2CTx-based cocatalysts by regulating the antibonding-orbital occupancy of Mo sites for improved photocatalytic performance.

Enhanced catalytic performance for gas phase epoxidation of propylene with H2 and O2 by multiple pretreated Au/TS-1 catalysts

Direct epoxidation of propylene (C3H6) with hydrogen (H2) and oxygen (O2) over Au/TS-1 catalyst was promising way for the synthesis of propylene oxide (PO). However, high selectivity of PO (>95 %) and conversion of C3H6 (>5 %) cannot be achieved at the same time. The industrialization process was severely restricted. In this paper, Au/TS-1 catalysts were synthesized by deposition precipitation method with alkali metal promoter. And alkaline gases and silane coupling post-treatment were performed to promote the catalytic activity. The prepared samples exhibited a much better C3H6 conversion (6.5 %) and PO selectivity (95.1 %) compared with general catalyst using normal synthetic technology. Cs2CO3 was beneficial to increasing Au nanoparticles uptake efficiency. Both NH3 and triethoxyvinylsilane post-treatment were good for smaller and more uniform loading of Au nanoparticles. The decreasing in surface hydroxyl density effectively alleviated the occurrence of PO ring opening isomerization. The increased hydrophobicity of TS-1 surface was conducive to the rapid desorption of generated PO and significantly increased PO selectivity. Multiple pretreatment was also favorable for extending the lifetime of Au/TS-1 catalyst.

Cooperative In Situ Impregnation of PEG and Au Nanoparticles into Expanded CNT Network Toward Composite Phase Change Fibers with High Storage Capacity and Photothermal Conversion

AbstractPhase change fibers with multifunctionalities are a promising material for thermal management applications, however, it is still challenging to simultaneously give the fiber high energy conversion and storage capacity. Here, a cooperative in situ impregnation strategy is reported, to introduce Au nanoparticles (NPs) and polyethylene glycol (PEG) together into carbon nanotube (CNT) network during the expansion process, resulting in a CNT/Au/PEG composite phase change fiber. The obtained composite fiber have the characteristics of high loading (up to 88.0–98.6%) and uniform distribution of Au NPs, and thus exhibits superior mechanical, electrical, and thermal properties. The presence of Au NPs plays more important role in not only improving the PEG crystallinity and phase change enthalpy, but also enhancing the photothermal conversion efficiency (up to 88.2%). There is also a new feature of precise regulation of the phase change temperatures, e.g., from 9.5 to 20.5 °C for the solidification temperature. More importantly, due to the strong confinement of PEG and Au NPs inside the CNT network, the composite fiber also shows excellent thermal stabilities, including the anti‐leakage behavior and cycling phase change ability.

Recyclable Au@R–Fe3O4/g-C3N4 substrates for rapid SERS detection and degradation of multiple pollutants

Developing a Surface-enhanced Raman spectroscopy (SERS) method with excellent detecting ability, good recyclability and analyzing multiple pollutants rapidly are critical for evaluation of water quality in emergency pollution affairs. While constructing a multifunctional substrate with these characteristics to realize the application of SERS in water quality monitoring remains a challenge. In this work, a reusable Au@R–Fe3O4/g-C3N4 SERS substrate is prepared by loading Au nanoparticles (Au NPs) on Fe3O4 nanorings (R–Fe3O4) and the formed Au@R–Fe3O4 is further combined with g-C3N4 nanosheets through a simple electrostatic assembly method. The Au@R–Fe3O4/g-C3N4 nanocomposite presents multifunction of magnetic enrichment, SERS signal enhancement, multiple pollutants analyzing, and photocatalytic activity, which achieves quantitative detection of rhodamine B (RhB), tetracycline hydrochloride (TC), and 4-chlorophenol (4-CP), with detection limits of 5.30 × 10−9, 7.50 × 10−8, 7.69 × 10−8 mol/L, respectively. Furthermore, the recyclable detection capability of Au@R–Fe3O4/g-C3N4 for multi components is demonstrated by the strong SERS signal after 9 cycles of “detection-degradation” processes. Combined with good uniformity and stability, this SERS method based on Au@R–Fe3O4/g-C3N4 substrate provides a new strategy for the multi-pollutants detection and degradation in water environment.

Tunneling Electron Transfer across Cell Membrane via Au Nanoparticles in Single Living Cells.

Herein, we present a new and simple electrochemical method to detect the intracellular electroactive substances by utilizing the electron tunnelling processes at the metal nanoparticles inside the cells. Intriguing discrete oxidation and reduction current spikes are obtained when testing the cells with loaded Au nanoparticles at the ultramicroelectrodes, which should come from reactive oxygen species (ROS) inside the single cell. The charges enclosed in the current spikes represent the ROS content inside the living cells, as confirmed by the fluorescence studies. As this simple electron tunnelling approach needs no nanoelectrodes or nanotip penetration processes, we believe it could have great potential applications in electrochemical analysis of single living cells.

Moringaoleifera leaves extract loaded Au nanoparticles offers a promising approach in protecting against experimental nephrotoxicity

Cisplatin is one of the most important antitumor drugs, however; it has numerous adverse effects like nephrotoxicity which is considered one of cisplatin uses disadvantageous.The aim of this study was to evaluate the nephroprotective effect of M. oleifera leaves extract loaded gold nanoparticles (Au-NPs) against cisplatin-induced nephrotoxicity in rats.Initially, total phenolic contents (TPC) and the antioxidant activity of the M. oleifera leaves were evaluated and recorded 8.50mg/g and39.89% respectively. After that, the dry leaves of M. oleifera were grinded into fine powder and extracted using water extraction system. Then, different volumes (0.5, 1 and 2mL) of M. Oleifera were blended with constant volume of Au-NPs (1mL). Both Au-NPs and M. oleifera extract loaded Au-NPs were extensively investigated using TEM that illustrated the deposition of M. Oleifera onto Au-NPs.The experimental study was performed on seventy male albino rats alienated into seven groups. Group I healthy rats, group II injected with one dose of cisplatin (CP), groups fromIII to VII treated groups received CisPt then received M. Oleifera leaves extract alone and /or Au-NPs with different ratios and concentrations.After the experiment’ time, serum urea and creatinine,kidney injury molecule-1 (KIM-1),advanced oxidation protein products (AOPP), monocyte chemoattractant protein-1 (MCP-1), tumor necrotic factor-α (TNF-α), and interleukin-6 (IL-6) were evaluated as markers of renal nephrotoxicity. The kidneys of rats were excised for malondialdehyde (MDA), nitric oxide (NO), and superoxide dismutase (SOD) assessments.Induction of CisPt showed a highly significant disturbance in oxidant/anti-oxidant balance and inducing inflammatory cascades supporting nephrotoxicity, while treatment with M. Oleifera leaves extract, Au-NPs, and the different concentrations of the extract loaded on Au-NPs had a crucial role in attenuating oxidative stress, enhancing antioxidant systems, and reducing inflammatory biomarkers, although the most significant results showed a powerful scavenging activity against nephrotoxicity induced by CisPt was obtained with M. Oleifera leaves extract loaded on Au-NPs with a concentration of 2:1respectively.

Au nanoparticles decorated β-Bi2O3 as highly-sensitive SERS substrate for detection of methylene blue and methyl orange.

In this work, Au/Bi2O3 was synthesized by loading Au nanoparticles (NPs) onto β-Bi2O3 by a simple solution reduction method. β-Bi2O3 was synthesized by a precipitation-thermal decomposition procedure, which results in significantly improved SERS detection limits down to 10-9 M for methylene blue (MB) and 10-7 M for methyl orange (MO) as probe molecules, comparable to those reported for the best semiconductor SERS substrates. In particular, further deposition of Au NPs (5.20% wt%) onto β-Bi2O3 results in a two-order-of-magnitude enhancement in detection sensitivity, achieving a detection limit of 10-11 M for MB and 10-9 M for MO. Under ultraviolet/visible irradiation, the Au/Bi2O3 hybrids substrate exhibits superior self-cleaning ability due to its photocatalytic degradation ability which can be applied repeatedly to the detection of pollutants. The advanced composite substrate simultaneously achieved ultra-low mass loading of Au NPs, outstanding detection performance, good reproducibility, high stability and self-cleaning ability. The development strategy of low load noble metal coupled high performance semiconductor β-Bi2O3 to obtain nano-hybrid materials provides a method to balance SERS sensitivity, cost effectiveness and operational stability, and can be synthesized in large quantities, which is a key step towards commercialization and has good reliability prospects.

Engineering surface lattice hydroxyl groups toward highly efficient photocatalytic methane coupling.

Nb3O7(OH) containing abundant surface lattice hydroxyl groups, combining with loaded Au nanoparticles as the cocatalyst, was employed as a photocatalyst enabling highly efficient photocatalytic CH4 coupling to C2H6 under mild conditions. In situ spectroscopy technique revealed that the surface lattice hydroxyl groups play a vital role in promoting the activation of CH4 to produce the methoxy intermediates, contributing to significantly enhanced catalytic performance for CH4 conversion.

One-pot synthesis of an Au modified BiOCOOH plasmonic photocatalyst with enhanced photocatalytic activity

In this work, we designed the plasmonic photocatalyst of Au–BiOCOOH through a one-pot method, which can be used to effectively treat wastewater contaminated with rhodamine (RhB) and tetracycline (TC). Compared with neat BiOCOOH, as expected, the resulting Au–BiOCOOH illustrated significantly boosted photocatalytic efficiency for degrading RhB and TC under visible light illumination. Remarkably, 3.0%Au–Bi showed the most optimal performance against RhB and TC, achieving degradation rates of 99.5 % and 99.7 % within 120 min. Through multiple characterization techniques, the physical and chemical photoelectric properties of the photocatalyst as well as the photocatalysis mechanism were discussed in detail. UV–visible diffuse reflectance spectroscopy (DRS) analysis demonstrates that the loading of Au nanoparticles (Au NPs) onto 2D nanosheets of BiOCOOH significantly expanded the wavelength range of response of BiOCOOH to visible light. Separately, the outcomes of electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) manifestly reveal that the presence of Au NPs on BiOCOOH can efficiently reduce the interfacial charge transfer resistance and accelerate the photogenerated charge transfer. The free radical trapping test provided evidence for the essential role played by holes (h+) and superoxide radicals (·O2−) were involved in the degradation of RhB. The study provided a possibility to improve the photocatalytic efficiency of BiOCOOH.

A Cleaner Approach for Controllable Synthesis of Au/TiO2 Nanocomposite as an Efficient Catalyst for 4‐Nitrophenol Reduction

AbstractSupported metal catalysts have attracted considerable attention because of their remarkably high catalytic activity and thermal stability. In this work, we report a facile and eco‐friendly method to synthesize porous Au/TiO2 nanocomposites with tunable size and different loading of Au nanoparticles. Porous TiO2 particles with average size of 20 nm were obtained using deep eutectic solvent‐assisted solvothermal method, in which Au NPs were immobilized by citrate reduction process. By adjusting the molar ratio of citrate and gold precursor, the size and loading of Au particles could be effectively controlled. The optimized nanocomposite with maximum Au loading and smallest particle size of 9 nm manifested the best catalytic activity in the 4‐nitrophenol reduction and excellent reusability. The superior catalytic performance can be ascribed to the strong interfacial interaction between small Au NPs and porous TiO2 support together with the high concentration of active sites at the interface.

Advanced cobalt-ferrite layered double hydroxides sandwich-structured nanozymes for ROS-bloomed tumor therapy

Artificial-engineered nanozymes show great promise for improving cancer therapeutic outcomes. Herein, we elaborately designed the advanced cobalt-ferrite layered double hydroxides (Co-Fe LDHs) sandwich-structured architectures that can serve as superior nanozymes with Co/Fe dual catalytic cycles and also be used as nanocarriers for loading Au nanoparticles (NPs) and maleimide (MA) to achieve the “all-in-one” reactive oxygen species (ROS)-bloomed tumor therapeutic strategy. The constructed Co-Fe LDHs@Au@MA nanozymes can not only enhance the oxidative stress in tumors through cascade enzymatic reactions but also disrupt the glutathione supply and further aggravate the tilt of the established redox homeostasis. The Co/Fe active sites are optimal by manipulating the Co/Fe-doped amount for obtaining the synergistic effect of multi-metallic enzyme-like activities. Besides, the mild photothermal effect of Au NPs facilitates the enhanced catalytic efficiency of Co-Fe LDHs but also initiates tumor cell apoptosis via the hyperthermia effect. In conclusion, this study presents a typical paradigm to utilize bi-functional LDHs-based nanozymes for tumor treatment with enhanced enzyme-like activities.

Electrochemical immunosensor based on hollow Pt@Cu2O as a signal label for dual-mode detection of procalcitonin

As a reliable biomarker to evaluate the severity of sepsis, sensitive and accurate detection of procalcitonin (PCT) is essential. In this study, a dual-mode electrochemical immunosensor based on Au/ZIF-8 as substrate and Pt@Cu2O as signal label was constructed for the detection of PCT. By loading Au nanoparticles onto rhombic dodecahedral ZIF-8, the substrate (Au/ZIF-8) has large specific surface area and can immobilize antibody (Ab1) by Au–N bonds. Meanwhile, hollow Pt@Cu2O nanocomposite with excellent peroxidase-like activity and electrocatalytic activity were synthesized as signal label. In the process of electrochemical testing, Pt@Cu2O catalyzed the reduction of hydrogen peroxide (H2O2) and further promotes the oxidation of hydroquinone (HQ) to achieve the synergistic amplification of electrochemical signals. The proposed immunosensor detected PCT by amperometric i-t and differential pulse voltammetry (DPV) tests with a good linear response and low limit of detection (i-t: 0.70 fg/mL and DPV: 0.40 fg/mL) in the range of 10 fg/mL∼100 ng/mL. The immunosensor exhibited excellent sensitivity and accuracy, indicating the potential application of this method for PCT detection.

Gold nanoparticles supported on ZnGa2O4 nanosheets as efficient photocatalysts for selective oxidation of methane to ethane under ambient conditions

In this study, we fabricated photocatalysts comprising of ZnGa2O4 nanosheets modified with gold (Au) nanoparticles for the selective oxidative coupling of methane (CH4). Our findings indicate that the C2H6 production rate of ZnGa2O4 with the optimal loading of Au nanoparticles (NPs) reached 1315.3 μmol g–1 h–1, with a selectivity of 53 %. These results were considerably higher than those obtained with pure ZnGa2O4. The presence of Au NPs facilitated the activation of O2 molecules, leading to the generation of superoxide ions (O2–), which were the primary active species responsible for the cleavage of CH4 into methyl radicals (•CH3). Additionally, Au NPs stabilized •CH3 and promoted the coupling of •CH3 into C2H6 while impeding the excessive oxidation of •CH3 into CO2. In conclusion, our study demonstrates that modifying ZnGa2O4 with Au NPs can significantly enhance the yield and selectivity of C2H6 during the photocatalytic oxidative coupling of CH4.

Physical Characteristics, Blue-Green Band Emission and Photocatalytic Activity of Au-Decorated ZnO Quantum Dots-Based Thick Films Prepared Using the Doctor Blade Technique.

Nanoscale ZnO is a vital semiconductor material whose versatility can be enhanced by sensitizing it with metals, especially noble metals, such as gold (Au). ZnO quantum dots were prepared via a simple co-precipitation technique using 2-methoxy ethanol as the solvent and KOH as the pH regulator for hydrolysis. The synthesized ZnO quantum dots were deposited onto glass slides using a simple doctor blade technique. Subsequently, the films were decorated with gold nanoparticles of different sizes using a drop-casting method. The resultant films were characterized via various strategies to obtain structural, optical, morphological, and particle size information. The X-ray diffraction (XRD) reveals the formation of the hexagonal crystal structure of ZnO. Upon Au nanoparticles loading, peaks due to gold are also observed. The optical properties study shows a slight change in the band gap due to Au loading. Nanoscale sizes of particles have been confirmed through electron microscope studies. P.L. studies display blue and blue-green band emissions. The significant degradation efficiency of 90.2% methylene blue (M.B.) was attained in natural pH in 120 min using pure ZnO catalyst while one drop gold-loaded catalysts, ZnO: Au 5 nm, ZnO: Au 7 nm, ZnO: Au 10 nm and ZnO: Au 15 nm, delivered M.B. degradation efficiency of 74.5% (in 245 min), 63.8% (240 min), 49.6% (240 min) and 34.0% (170 min) in natural pH, respectively. Such films can be helpful in conventional catalysis, photocatalysis, gas sensing, biosensing, and photoactive applications.

Fabrication of Adjustable Au/Carbon Hybrid Nanozymes with Photothermally Enhanced Peroxidase Activity and Ultra-sensitivity for Glutathione Detection

Au nanozymes are extensively researched for their photothermal effect and catalytic performance, but overcoming the inherent defects of poor dispersibility and thermal stability through complementary materials will expand their prospects for biological applications. Herein, several novel CAu nanozymes were fabricated by in situ reduction of chloroauric acid on hollow carbon nanospheres (HCNs). Through regulating the number of reductions, sesame ball-shaped CAu (sCAu) with highly dispersed Au nanoparticles and diversity-shaped CAu (dCAu) were obtained. The number and morphology of loaded Au nanoparticles, absorption spectra, and hydrophilicity of CAu nanozymes were systematically characterized to demonstrate the flexibility of this novel method. The high-efficiency peroxidase-like sCAu0.3 nanozyme with hyperthermia-activated property was then screened for later bio-application. It is worth mentioning that its photothermal-promoted peroxidase-like activity could be achieved under near-infrared laser irradiation. Moreover, sCAu0.3 could specifically achieve glutathione detection in human blood samples. This method will provide a protocol for the regulation of CAu nanozymes to adapt to bio-detection applications.

Highly sensitive photoelectrochemical and electrochemical dual-mode biosensing of polynucleotide kinase based on multifunctional BiOBr0.8I0.2 /CuSCN composite and biocatalytic precipitation

Polynucleotide kinase (PNK) plays an important role in maintaining genome integrity and is directly related to many severe human diseases, so its detection is of great significance. To accurately and reliably detect PNK, a photoelectrochemical (PEC) - electrochemical (EC) dual-mode biosensor is created based on BiOBr0.8I0.2/CuSCN multifunctional nanocomposite. In this protocol, the nanocomposite loaded Au nanoparticles (AuNPs) are used to immobilize capture probe P1, while the signal probe P2 is labeled by glucose oxidase modified AuNPs (GOx@AuNPs-P2). They precisely hybridize to produce a double-stranded DNA (ds-DNA)-contained composite at the ITO electrode, which can be phosphorylated in the presence of PNK before being cleaved selectively by λ-exonuclease and leaving the electrode surface. The uncut ds-DNA with GOx@AuNPs-P2 catalyzes glucose to generate H2O2, and under the catalysis of peroxidase-like BiOBr0.8I0.2/CuSCN, 4-chlorohexadione precipitation is produced, which amplifies PEC and EC signals. Owing to the coordination effect of different elements, including enzyme and aptamers, the proposed PEC-EC dual-mode platform displays high sensitivity and selectivity. Furthermore, the sensor shows high repeatability and stability. Further experiments indicate it has excellent application potential in the detection and inhibitor screening of PNK.