Bismuth Oxychloride Nanosheets Research Articles

Hydrothermal synthesis of W-doped BiOCl nanoplates for photocatalytic degradation of rhodamine B under visible light

Doping bismuth oxychloride (BiOCl) with other elements can help improve its photocatalytic performance. The present study used a simple one-step hydrothermal method to synthesize tungsten-doped BiOCl nanosheets. The results showed the negligible effects of W-doping on the crystal structure, morphology and specific surface area of BiOCl. Diffuse reflectance spectroscopy (DRS), however, showed increases in light absorption and a shift in the absorption edge towards higher wavelengths in the presence of W. Measuring the photocatalytic performance of the samples in decomposing an aqueous solution of rhodamine B (RhB) under light irradiation showed that doping BiOCl with W preserves photocatalytic performance under both UV irradiation and visible-light irradiation, whereas pure BiOCl showed negligible photocatalytic activities under visible-light irradiation. The high photocatalytic activity of BiOCl doped with W compared to that of pure BiOCl is explained by the reduction in band gap and increase in light absorption due to the formation of W energy bands in the forbidden energy gap of BiOCl. A plausible mechanism was proposed for the photocatalytic activity of W-doped BiOCl in decomposing RhB under visible light.

Piezoelectric materials for ultrasound-driven dissociation of Alzheimer's β-amyloid aggregate structure

Piezoelectric materials can evoke electrochemical reactions by transferring charge carriers to reactants upon receiving mechanical stimuli. We report a newly discovered function of piezoelectric bismuth oxychloride (BiOCl) nanosheets for dissociating Alzheimer's β-amyloid (Aβ) aggregates through ultrasound-induced redox reactions. The accumulation of Aβ aggregates (e.g., Aβ fibrils, plaques) in the central nervous system is a major pathological hallmark of Alzheimer's disease (AD). Thus, clearing Aβ aggregates is considered a key for treating AD, but the dissociation of Aβ aggregates is challenging due to their extremely robust structure consisting of β-sheets. BiOCl nanosheets are a biocompatible piezoelectric material with piezocatalytic activity in response to ultrasound. Our analyses using multiple spectroscopic and microscopic tools have revealed that BiOCl nanosheets effectively disassemble Aβ fibrils under ultrasound stimulation. Sono-activated BiOCl nanosheets produce piezo-induced oxidative stress, which effectively destabilizes the β-sheets in Aβ fibrils. In vitro evolution has also shown that sono-activated BiOCl nanosheets can effectively alleviate the neuro-toxicity of Aβ fibrils. Furthermore, ex vivo evolution demonstrated that amount of Aβ plaques in AD mouse's brain slices was drastically reduced by treatment with sono-activated BiOCl nanosheets.

Crack Formation on Crystalline Bismuth Oxychloride Thin Square Sheets by Using a Wet‐Chemical Method

AbstractThe morphology of nanocrystals is crucial in modulating their properties including optical, chemical and catalytic ones. For the intensively studied sheet‐like structures, it is also important to engineer their detailed nanostructures on sheet surfaces. In this work, micron‐sized bismuth oxychloride (BiOCl) thin square sheets in tetragonal matlockite‐like phase and the corner‐truncated ones were successfully synthesized by using a simple wet‐chemical method. These square sheets could be partially etched, forming surface cracks with the size and density easily tuned. Two different types of cracks were observed on the surfaces of the corner un‐truncated and truncated BiOCl square sheets. Surprisingly, radial cracks formed on the corner‐truncated BiOCl sheets, which is attributed to the existence of physical stress during the etching and is highly related to the original nanostructure of the BiOCl sheets. This work provides a wet‐chemical method for engineering surface cracks, especially radial cracks, on the surfaces of BiOCl nanosheets, which may be expanded to surface engineering of other nanosheets and will show a great potential in various fields.

BiOCl/TiO2/diatomite composites with enhanced visible-light photocatalytic activity for the degradation of rhodamine B.

A BiOCl/TiO2/diatomite (BTD) composite was synthesized via a modified sol–gel method and precipitation/calcination method for application as a photocatalyst and shows promise for degradation of organic pollutants in wastewater upon visible-light irradiation. In the composite, diatomite was used as a carrier to support a layer of titanium dioxide (TiO2) nanoparticles and bismuth oxychloride (BiOCl) nanosheets. The results show that TiO2 nanoparticles and BiOCl nanosheets uniformly cover the surface of diatomite and bring TiO2 and BiOCl into close proximity. Rhodamine B was used as the target degradation product and visible light (λ > 400 nm) was used as the light source for the evaluation of the photocatalytic properties of the prepared BTD composite. The results show that the catalytic performance of the BTD composite under visible-light irradiation is much higher than that of TiO2 or BiOCl alone. When the molar ratio of BiOCl to TiO2 is 1:1 and the calcination temperature is 400 °C, the composite was found to exhibit the best catalytic effect. Through the study of the photocatalytic mechanism, it is shown that the strong visible-light photocatalytic activity of the BTD composite results mainly from the quick migration of photoelectrons from the conduction band of TiO2/diatomite to the surface of BiOCl, which promotes the separation effect and reduces the recombination rate of the photoelectron–hole pair. Due to the excellent catalytic performance, the BTD composite shows great potential for wide application in the field of sewage treatment driven by solar energy.

BiOCl-Coated Electroactive Film for Potential-Triggered Selective Removal of Cesium Ions from Simulated Wastewater

Bismuth oxychloride (BiOCl)-coated electroactive film was fabricated for the separation of cesium ions based on a potential-triggered method. The effects of applied potential, conductive carbon black (Super P Li), and different exposed facets on the adsorption of Cs+ ions were investigated. Experiments revealed that the adsorption efficiency gradually improved with increasing the applied potential to −0.7 V. The introduction of Super P Li improved the adsorption rate and increased the separation efficiency. The adsorption behavior followed pseudo-second-order kinetics. Additionally, the electroactive film showed adsorption selectivity for Cs+ in preference to Li+, Na+, and Rb+; seven consecutive adsorption–desorption experiments indicated that the electroactive film is sensitive to potential. The BiOCl nanosheets with exposed (001) facets exhibited a higher adsorption ratio for Cs+ removal than the counterpart with exposed (101) facets. It was also found that the separation performance of Cs+ ions was bes...

Improved photocatalytic degradation of perfluorooctanoic acid on oxygen vacancies-tunable bismuth oxychloride nanosheets prepared by a facile hydrolysis.

Oxygen vacancies (OVs) defective BiOCl nanosheets are important for developing efficient hole (h+) oxidation. Herein, a facile hydrolysis without the use of organic solvent was developed for preparing OVs-controllable BiOCl nanosheets, which was then applied to degrade perfluorooctanoic acid (PFOA), a typical persistent organic pollutant, which is resistance to the oxidation by hydroxyl radicals (OH). As changing the alkali source in the preparation process, the ratio of OVs in BiOCl nanosheets increases from 0.573 to 0.981, and the photocatalytic performance of BiOCl for the degradation and defluorination of PFOA increases by 3-4 times. A linear relationship between the photocatalytic degradation of PFOA and the OVs amount in BiOCl was observed. The introduction of OVs in BiOCl not only offers localized states for trapping photo-generated electrons, but also acts as active sites for adsorbing PFOA, both of which are helpful to improve the h+-oxidation of PFOA. The photocatalytic degradation of PFOA was more effective at pH 4.6 compared to other previously reported highly acidic and alkaline conditions. These factors ultimately guaranteed the improved degradation and defluorination of PFOA over OVs-rich BiOCl nanosheets. This work provides a readily achievable tactic to induce OVs formation on nanocrystals for enhanced photocatalytic water treatment.

Composite microsphere resulting from assembly of BiOCl nanosheets and palygorskite nanorods for enhanced photocatalytic activity

3D palygorskite (PAL)/bismuth oxychloride (BiOCl) composite microspheres were easily synthesized through a facile room temperature reaction, in which BiOCl was coupled with palygorskite (PAL) to form PAL/BiOCl nanocomposites. The employment of PAL significantly exerted great effects on the morphologies and visible-light photocatalytic performance of PAL/BiOCl nanocomposites. With gradually increasing the PAL amounts, the 3D composite microspheres were assembled with BiOCl nanosheets and palygorskite nanorods. The nanocomposites exhibited enhanced photocatalytic activities for degrading rhodamine B (RhB) under visible light irradiation, owing to its 3D hierarchical microsphere nanostructure and constructed composite with well-matched band structure and tight intercontact.

Low‐Crystalline NiS Hybridized with BiOCl Nanosheet as Highly Efficient Electrocatalyst for Dye‐Sensitized Solar Cells

AbstractLow‐crystalline nickel sulfide (NiS) nanoparticles are firstly hybridized with single‐crystalline bismuth oxychloride (BiOCl) nanosheets (denoted as NiS/BiOCl) via in‐situ pyrolysis of a NiCl2‐BiCl3‐thiourea precursor at low temperature (250 °C). The idea involved is to combine the functions of low‐crystalline NiS for catalyzing I3− to I− and BiOCl nanosheets for offering fluent charge transport pathway. Especially, in‐situ hybridization leads to close assembly and strong interaction between NiS nanoparticles and BiOCl nanosheets, further enabling the synergetic electronic coupling between the two phases. As a result, the hybrid NiS/BiOCl film can catalyze the reduction of I3− at an extremely low charge transfer resistance of 0.21 Ω cm2, versus 1.63 Ω cm2 for Pt. When used as counter electrode for dye‐sensitized solar cells, device using NiS/BiOCl film as counter electrode produces a high power conversion efficiency of 7.88%, versus 7.35% for Pt under the same conditions. Furthermore, low‐crystalline NiS/BiOCl film can also catalyze oxygen evolution reaction with a current density of 10 mA cm−2 at 1.61 V vs. RHE and a Tafel slope of 113 mV dec−1, which is potentially useful for many operational clean energy devices. Our study thus provides new opportunities for the development of highly efficient hybrid electrocatalyst in a facile and energy‐saving strategy.

UV Photodetectors Based on BiOCl Nanosheet Arrays: The Effects of Morphologies and Electrode Configurations.

A facile chemical bath method is adopted to grow bismuth oxychloride (BiOCl) nanosheet arrays on a piece of Cu foil (denoted as BiOCl-Cu) and isolated BiOCl nanosheets are collected by ultrasonication. A self-supporting BiOCl film is obtained by the removal of Cu foil. Photodetectors (PDs) based on these BiOCl materials are assembled and the effects of morphologies and electrode configurations on the photoelectric performance of these PDs are examined. The BiOCl nanosheet PD achieves high responsivities in the spectral range from 250 to 350 nm, while it presents quite a small photocurrent and slow response speed. The BiOCl film PD yields low photocurrents and near-unity on-off ratios, demonstrating poor photoelectric performance. The photocurrent of the BiOCl-Cu PD with both electrodes on the BiOCl film is much higher than those of these above-mentioned PDs, and the response times are fast. Meanwhile, the BiOCl-Cu PD with separate electrodes on the BiOCl film and Cu foil achieves even higher photocurrents and presents a self-powering characteristic, depicting the improved photodetecting performances induced by the specific morphology and distinct electrode configuration. These results would promote the applications of BiOCl nanostructures in the photoelectric devices.

Photocatalytic degradation of ibuprofen over BiOCl nanosheets with identification of intermediates

Photocatalysis directed at the removal of persistent organic pollutants, including pharmaceuticals, has been the subject of intense recent research. Bismuth oxychloride (BiOCl) has emerged as a potential alternative to traditional photocatalysts and has shown competitive removal efficiencies. However, pathways responsible for BiOCl photodegradation have not been well characterized. The present work is the first to determine, using LC-MS/MS analysis, the pathways by which BiOCl removes ibuprofen (IBP) from water. HPLC-DAD and LC-MS/MS analyses show that BiOCl converts IBP to two primary photochemical products, 4-isobutylacetophenone (IBAP) and 1-(4-isobutylphenyl)ethanol (IBPE). The reactivity for BiOCl is attributed to interactions of the carboxylic acid group of IBP with holes in the valence band. Hydroxylated-IBP was not detected in BiOCl photocatalytic degradation experiments which would be expected in a process driven by the formation and reactivity of reactive oxygen species. These data were used to formulate a photocatalytic degradation pathway for IBP and highlight the importance of studying both primary and secondary degradation reactions for photocatalytic studies.

Bismuth oxychloride (BiOCl)/copper phthalocyanine (CuTNPc) heterostructures immobilized on electrospun polyacrylonitrile nanofibers with enhanced activity for floating photocatalysis

The 2,9,16,23-tetranitro phthalocyanine copper (II) nanostructures and bismuth oxychloride nanosheets were grown on electrospun polyacrylonitrile (PAN) nanofibers in sequence by solvothermal method. As a result, the BiOCl/CuTNPc heterostructures were uniformly immobilized on the PAN nanofibers. The obtained BiOCl/CuTNPc/PAN nanofibers had excellent photocatalytic activity for the degradation of rhodamine B (RhB) under UV–vis light irradiation. The first-order rate constant of the BiOCl/CuTNPc/PAN nanofibers was 5.86 and 6.31 times as much as CuTNPc/PAN and BiOCl/PAN nanofibers, respectively. The high photocatalytic activity could be attributed to the formation of BiOCl/CuTNPc heterostructures, which helped the separation of the photogenerated electron–hole pairs. Concurrently, the marcoporous structure of the BiOCl/CuTNPc/PAN nanofibers improved the photocatalytic activity due to the increased interface contacts between the photocatalyst and the RhB solution. The BiOCl/CuTNPc/PAN nanofibers did not need to be separated for reuse due to their flexible self-supporting properties originating from the PAN nanofibers. Moreover, the film-like BiOCl/CuTNPc/PAN nanofibers could float easily on the liquid and maximize the absorption of sunlight during photocatalysis. It was expected that the BiOCl/CuTNPc/PAN nanofibers with high photocatalytic activity and easily separable property will possess great potential in the field of industrial applications and environmental remediation.

Bismuth Oxychloride/MXene symmetric supercapacitor with high volumetric energy density

Since the discovery of two-dimensional (2D) graphene, a new class of 2D materials with excellent electrical conductivity has recently been attracting attention in studying promising electrode materials in energy storage applications. Herein, bismuth oxychloride nanosheets-immobilised Ti3C2Tx MXene material (TCBOC) is synthesised by a facile and cost-effective chemical bath deposition (CBD) route. The bismuth oxychloride (BiOCl) nanosheets are grown and immobilised on surfaces of Ti3C2Tx-MXene flakes. An electrode based on the TCBOC nanocomposite exhibited a remarkably volumetric specific capacitance of 396.5 F cm-3 at 1 A g−1 and 228.0 F cm-3 at 15 A g−1. Furthermore, a symmetric supercapacitor (SSC) assembled using TCBOC material proves to have a high energy density of 15.2 Wh kg−1 at a power density of 567.4 W kg−1 compared to SSCs using previously reported Ti3C2Tx MXene materials. The SSC shows cycle life retention of 85.0% after 5000 cycles (at 5 A g−1). The enhanced capacitive performance is attributed to the increased surface area due to BiOCl nanosheets anchored on a 2D MXene surface, the activities of BiOCl sheets, and the excellent conductivity of a Ti3C2Tx MXene material.

Nanojunction-mediated visible light photocatalytic enhancement in heterostructured ternary BiOCl/ CdS/g-C3N4 nanocomposites

BiOCl/CdS/g-C3N4 heterostructure and related photcatalysts have been designed successfully by decorating the 2D organic graphitic carbon nitride (g-C3N4) and inorganic bismuth oxychloride (BiOCl) semiconductor nanosheets with cadmium sulphide (CdS) nanoparticles. We have employed solvothermal cum co-precipitation method to fabricate the photocatalysts. The morphologies, optical and electronic properties of the photocatalysts have been studied by spectroscopic and microscopic methods. The BiOCl/CdS/g-C3N4 photcatalyst shows remarkably high visible-light-driven photocatalytic activity for the degradation of rhodamine B (RhB) with first order rate constant of 0.09 min−1. The observed photodegradation activity is of the order, BiOCl/CdS/g-C3N4 > CdS/g-C3N4 > BiOCl/g-C3N4 > g-C3N4. Radical scavenging experiments show that superoxide radicals (O•−2) and holes (h+) are more active species in the photodegradation of RhB than hydroxyl radicals (O•H). This study reveals that morphology and synergic interactions of BiOCl and g-C3N4 nanosheets with CdS nanoparticles are crucial to separate the photogenerated electron-hole pairs and enhance the photocatalytic activity for RhB degradation.

Hierarchical heterostructures of p-type bismuth oxychloride nanosheets on n-type zinc ferrite electrospun nanofibers with enhanced visible-light photocatalytic activities and magnetic separation properties

P-type bismuth oxychloride (p-BiOCl) nanosheets were uniformly grown on n-type zinc ferrite (n-ZnFe2O4) electrospun nanofibers via a solvothermal technique to form hierarchical heterostructures of p-BiOCl/n-ZnFe2O4 (p-BiOCl/n-ZnFe2O4 H-Hs). The density and loading amounts of the BiOCl nanosheets with exposed {0 0 1} facets were easily controlled by adjusting the reactant concentration in the solvothermal process. The p-BiOCl/n-ZnFe2O4 H-Hs exhibited enhanced visible-light photocatalytic activities for the degradation of Rhodamine B (RhB). The apparent first-order rate of the p-BiOCl/n-ZnFe2O4 H-Hs and its normalized constant were about 12.6- and 8-fold higher than pure ZnFe2O4 nanofibers. This suggests that both the improved charge separation efficiency from the uniform p-n heterojunctions and the enlarged active surface sites from the hierarchical structures increase the photocatalytic performances. Furthermore, the p-BiOCl/n-ZnFe2O4 H-Hs could be efficiently separated from the solution with an external magnetic field via the ferromagnetic behavior of ZnFe2O4 nanofibers. The magnetic p-BiOCl/n-ZnFe2O4 H-Hs with enhanced visible-light photocatalytic performances might have potential applications in water treatment.

Enhanced photocatalytic degradation of bisphenol A by Co-doped BiOCl nanosheets under visible light irradiation

Bismuth oxychloride (BiOCl) is a typical UV-light-sensitive photocatalyst with a unique layered structure, but exhibits no response towards visible light. This is a main limitation for its practical applications in photocatalytic degradation of pollutants. Among various methods to expand the light absorption region, doping modification is an efficient approach because it can tailor the band structure by forming a doping energy level without changing the layered structure substantially. In this case, the static electric field in the BiOCl crystal can be retained. Since cobalt (Co) exhibits good electrochemical properties, it is an ideal element for doping modification to expand the light absorption region and enhance the charge separation efficiency of BiOCl. In this work, Co-doped BiOCl nanosheets were prepared using a simple hydrothermal route. The doped Co expanded the light absorption region and enhanced the charge separation efficiency by forming a doping energy level in the band gap of BiOCl. As a result, the Co-BiOCl nanosheets exhibited an outstanding photocatalytic performance in degrading bisphenol A (BPA) under visible light irradiation with a degradation rate of 3.5 times higher than that of BiOCl. On the basis of the experimental results and density functional theory calculations, the mechanism of visible-light-driven catalytic BPA degradation by the Co-BiOCl nanosheets was elucidated. Therefore, the feasibility of Co-doping modification for BiOCl was confirmed, and a novel and efficient strategy was provided for the design and synthesis of high-performance photocatalysts.

BiOCl Nanosheets with Controlled Exposed Facets and Improved Photocatalytic Activity

Bismuth oxychloride (BiOCl) single crystal nanosheets with controllable and highly exposed {001} facets have been synthesized via hydrolytic methods without any surfactants. The BiOCl nanosheets had a thickness from 30 to 120 nm and were synthesized by tuning evaporation temperature, while the ratio of {001} facets varies from 98 to 49%. A growth rate in {001} facets agrees with the Boltzmann function and a possible growth mechanism has been proposed. Moreover, the existence of highly exposed {001} facets could gradually narrow the band gap of BiOCl nanosheets. This work provides a new insight for controllable synthesis of layered materials with different facets, and provides a flexible strategy for exploring and enhancing photoactivity based on the facets engineering.

One-Step and Surfactant-Free Fabrication of Gold-Nanoparticle-Decorated Bismuth Oxychloride Nanosheets Based on Laser Ablation in Solution and Their Enhanced Visible-Light Plasmonic Photocatalysis.

A simple synthetic route is presented for fabricating gold nanoparticle (NP)-decorated bismuth oxychloride (BiOCl) nanosheets in one step based on laser ablation of a gold target in a hydrochloric acid solution of bismuth nitrate without surfactant. After laser ablation, BiOCl nanosheets with attached Au NPs are obtained. The nanosheets are sub-micron in the planar dimension and around 20 nm thick, and the Au NPs are a mean size of approximately 20 nm. Further experiments reveal that such Au-NP-decorated nanosheets could be formed at a large Cl/Bi molar ratio range (0.01 to 3) in solution. The formation of the BiOCl nanosheets is attributed to the Au plasma plume-induced local fast hydrothermal reaction, which drives the planar growth of BiOCl. Importantly, these Au-NP-decorated BiOCl nanosheets exhibit high photodegradation activity on rhodamine B, a typical organic pollutant, compared with bare nanosheets under visible light irradiation, and show highly stable and recyclable performance. This is attributed to the plasmonic properties of Au NPs, which increase optical absorption and promote separation of electron-hole pairs in the NP-decorated BiOCl nanosheets. This work provides not only a new plasmonic photocatalyst for the oxidative degradation of organic pollutants, but also a general method for fabrication of the metal-NP-decorated nanosheets of other layer-structured oxychlorides.

Novel Iron Bismuth Oxychloride Nanosheets for Lithium Ion Batteries

Iron Bismuth Oxychloride nanosheets were successfully synthesized by facile hydrolysis method. The X-ray photoelectron spectroscopy (XPS) shows composition was uniformly controlled as Fe0.3Bi0.7OCl. UV-Vis spectra and cyclic voltammetry (CV) results show the band gap of nanosheets correspondingly decreased from 3.4 eV for BiOCl to 2.08 eV for Fe0.3Bi0.7OCl due to raising of the valence band edge. Activation energy for electrical conductivity reduced from 862 meV to 796 meV for BiOCl and Fe0.3Bi0.7OCl, respectively. Density functional theory calculations predict changes to the valence band and decrease in the Fermi level toward the valence band edge for the Fe0.3Bi0.7OCl nanosheets - in accordance with experimental data. Correspondingly the Li ion capacities increased from 215 mAh/g for BiOCl to 542 mAh/g for Fe0.3Bi0.7OCl after 50 cycles at the current density of 100 mA/g.

Facile synthesis of a rose-like BiOCl assembled from nanosheets and its thermal-property application in polymers

Rose-like bismuth oxychloride (BiOCl) assembled from nanosheets has been successfully synthesized by a facile method at room temperature. The rose-like BiOCl is then introduced into poly (methyl methacrylate) (PMMA) via in situ polymerization. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) results indicate the rose-like BiOCl is exfoliated into individual nanosheets during polymerization process, and the nanosheets are homogenously distributed in the matrix. The as-fabricated PMMA/rose-like BiOCl nanocomposites exhibit remarkably enhanced thermal property including increased glass transition temperature (Tg) and onset thermal degradation temperatures, which are attributed to the barrier effect and excellent thermal insulating property of BiOCl nanosheets, and strong hydrogen bonding between BiOCl nanosheets and matrix. This work demonstrates the potential application of rose-like BiOCl for enhancing thermal property of polymers.

Immobilization of aptamer-modified gold nanoparticles on BiOCl nanosheets: Tunable peroxidase-like activity by protein recognition.

A self-assembled nanocomposite is prepared from an aqueous mixture of aptamer-modified gold nanoparticles (Apt-Au NPs), bismuth ions and chloride ions. The Apt-Au NPs are immobilized on bismuth oxychloride (BiOCl) nanosheets in situ to form Apt-Au NPs/BiOCl nanocomposites. The as-prepared nanocomposites exhibit high peroxidase-like activity for the catalytic conversion of Amplex Red (AR) to fluorescent resorufin in the presence of H2O2. The catalytic activity of Apt-Au NPs/BiOCl nanocomposites is at least 90-fold higher than that of Apt-Au NPs or BiOCl nanosheets, revealing synergistic effects on their activity. The catalytic activity of Apt-Au NPs/BiOCl nanocomposites is suppressed by vascular endothelial growth factor-A165 (VEGF-A165) molecules that specifically interact with the aptamer units (Del-5-1 and v7t-1) on the nanocomposite surface. The AR/H2O2-Apt-Au NPs/BiOCl nanocomposites probe shows high selectivity (>1000-fold over other proteins) and sensitivity (detection limit ~0.5nM) for the detection of VEGF-A165. Furthermore, the probe is employed for the detection of VEGF isoforms and for the study of interactions between VEGF and VEGF receptors. The practicality of this simple, rapid, cost-effective probe is validated by the analysis of VEGF-A165 in cell culture media, showing its great potential for the analysis of VEGF in biological samples.