Facile Detection Research Articles

Iron protoporphyrin IX-hyaluronan hydrogel-supported luminol chemiluminescence for the detection of nitric oxide in physiological solutions

Due to its role as a free radical signal-transducing agent with a short lifespan, precise measurement of nitric oxide (●NO) levels presents significant challenges. Various analytical techniques offer distinct advantages and disadvantages for ●NO detection. This research aims to simplify the detection process by developing a hydrogel system using iron(III)-protoporphyrin IX (hemin)-loaded hyaluronan for the detection of ●NO in solution. Various hydrogel formulations were created, and the effects of their components on hydrogel-supported luminol chemiluminescence (CL) kinetics, radical scavenging, and physicochemical properties were analysed through factorial analysis. The candidate formulations were then evaluated using two ●NO donors. An increase in the degree of crosslinking in unloaded formulations enhanced interactions with the CL reaction components, hydrogen peroxide (H2O2) and luminol, thereby affecting light generation. However, hemin loading negated these effects, resulting in more prominent luminescence kinetics in formulations with lower crosslinking degrees. Similarly, ●NO influenced the kinetics differently, interacting with both the CL reaction and hydrogel components. Hemin-loaded formulations exhibited enhanced signal propagation when exposed to ●NO, followed by H2O2 and luminol, whereas reversing the order of addition inhibited this propagation. The magnitude of these luminescence changes depended on the type and concentration of the ●NO donor, demonstrating greater sensitivity to ●NO levels compared to amperometric sensing. These findings suggest that the studied hydrogel platform has potential for the facile and accurate detection of ●NO in solution, requiring minimal sample sizes.

Luminol-Eu3+-Gd3+-functionalized mesoporous silica for ultrasensitive detection of tetracycline antibiotics and smartphone-assisted sensing analysis

An organic-inorganic hybrid nanoprobe, namely LML-D-SBA@Eu3+-Gd3+, was constructed, with SBA-15 acting as the carrier material, and luminol and Eu3+ acting as fluorescence channels to achieve ratiometric signals that eliminate external interference (accurate detection). Gd3+ was used as a sensitizer to amplify the red emission of Eu3+ (ultrasensitive detection). In TCs detection, the luminol emission at 428 nm was quenched due to the photoinduced electron transfer mechanism, and the Eu3+ emission at 617 nm was sensitized due to the synergistic energy transfer from TCs and Gd3+ to Eu3+. The fluorescence intensity at 617 and 428 nm showed ratiometric changes as indicated by notable color changes from blue to red. The detection limits for TC and OTC were 0.21 and 0.08 ng/mL, respectively. To realize a facile, rapid, and cost-effective detection, we constructed a portable intelligent sensing platform based on smartphones, and it demonstrated great potential for on-site detection of TCs.

A dual-signal optical sensing platform of CDs-MnO2 NS composites for facile detection of ascorbic acid based on a combination of Tyndall effect scattering and fluorescence.

A dual-signal optical sensing platform was successfully developed for the determination of ascorbic acid (AA) based on blue fluorescent carbon dots (CDs) and manganese dioxide nanosheets (MnO2 NSs) with strong Tyndall effect (TE) scattering and fluorescence quenching capabilities. In this nanosystem, CDs-MnO2 NS composites were employed as probes to evaluate the AA concentration. Owing to the strong reduction, the presence of the target AA could reduce the MnO2 NSs to Mn2+ and induce the degradation of the MnO2 NSs, resulting in a significant decrease in the TE scattering intensity of the MnO2 NSs and the fluorescence recovery of the CDs. Therefore, a novel optical sensor based on TE scattering and fluorescence dual detectors was developed for the sensitive determination of AA. Under optimized conditions, the limits of detection (LODs) of the two modes were 113 and 3 nM, respectively. Furthermore, the dual-signal optical sensing platform was successfully applied for the detection of AA in human serum.

Electrochemical biosensor based on RNA aptamer and ferrocenecarboxylic acid signal probe for C-reactive protein detection

Monitoring health-related biomarkers using fast and facile detection techniques provides key physicochemical information for disease diagnosis or reflects body health status. Among them, electrochemical detection of various bio-macromolecules, e.g., the C-reactive protein (CRP), is of great interest in offering potential diagnosis for acute inflammation caused by infections, heart diseases, etc. Herein, a novel electrochemical aptamer biosensor was constructed from Ti3C2Tx MXene and in-situ reduced Au NPs for thiolated-RNA aptamer immobilization and CRP protein detection using Fc(COOH) as the signal probe. The sensory performances for CRP detection were optimized based on working conditions, including the incubation times and the pH. The large surface area offered by Ti3C2Tx MXene and high electrical conductivity originating from Au NPs endowed the as-fabricated aptamer biosensor with a decent sensitivity for CRP in a wide linear range of 0.05–80.0 ng/mL, good selectivity over interfering substances, and a low detection limit of 0.026 ng/mL. Such aptamer biosensors also detected CRP in serum samples using the spike & recovery method with reasonable recovery rates. The results demonstrated the potential of the as-fabricated electrochemical aptamer biosensor for fast and facile CRP detection in practical applications.

Label-Free Ratiometric Homogeneous Electrochemical Strategy Based on Exonuclease III-Aided Signal Amplification for Facile and Rapid Detection of miR-378.

MiR-378 is abnormally expressed in various cancers, such as hepatocellular carcinoma, renal cell carcinoma, and nonsmall cell lung cancer. Here, we developed a label- and immobilization-free ratiometric homogeneous electrochemical strategy based on exonuclease III (Exo III) for the facile and rapid determination of miR-378. Two 3'-protruding hairpin DNA probes (HPs) are designed in this strategy. Doxorubicin (DOX) and potassium ferrocyanide (Fe2+) were used as label-free probes to produce a response signal (IDOX) and a reference signal (IFe2+) in the solution phase. When no target was present in the solution, the HP was stable, most of the DOX was intercalated in the stem of the HP, and the diffusion rate of DOX was significantly reduced, resulting in reduced electrochemical signal response. When miR-378 was present, double-cycle signal amplification triggered by Exo III cleavage was initiated, ultimately disrupting the hairpin structures of HP1 and HP2 and releasing a large amount of DOX into the solution, yielding a stronger electrochemical signal, which was low to 50 pM. This detection possesses excellent selectivity, demonstrating high application potential in biological systems, and offers simple and low-cost electrochemical detection for miR-378.

Guest-Responsive Near-Infrared-Luminescent Metal-Organic Cage Organized by Porphyrin Dyes and Yb(III) Complexes.

Metal-organic cages (MOCs) with luminophores have significant advantages for the facile detection of specific molecules based on turn-on or turn-off luminescence changes induced by host-guest complexation. One important challenge is the development of turn-on-type near-infrared (NIR)-luminescent MOCs. In this study, we synthesized a novel MOC consisting of two porphyrin dyes linked by four Yb(III) complexes, which exhibit bimodal red and NIR fluorescence signals upon photoexcitation of the porphyrin π system. Single-crystal X-ray structural analysis and computational molecular modeling revealed that planar aromatic perfluorocarbons were intercalated into the MOC. The tight packing between the MOC and guests enhanced the NIR fluorescence of Yb(III) by suppressing energy transfer from the photoexcited porphyrin to oxygen molecules. Guest-responsive turn-on NIR fluorescence changes in an MOC were successfully demonstrated.

Dual-ligand lanthanide metal-organic framework based ratiometric fluorescent platform for visual monitoring of aminoglycoside residues in food samples

Herein, a dual-emission Eu metal-organic framework (Eu-MOF) is prepared and used as the ratiometric fluorescence probe for ultrasensitive detection of aminoglycoside antibiotics (AGs). Due to the strong hydrogen bond interactions between AGs and Eu-MOF, the blue emission is enhanced while the red emission has little fluctuation in Eu-MOF with the addition of AGs, thus a good linear relationship with the logarithm of AGs concentrations from 0.001 to 100 μg/mL can be established for quantitative analysis. Good sensitivity with the detection limit of 0.33 ng/mL for apramycin, 0.32 ng/mL for amikacin and 0.30 ng/mL for kanamycin is achieved. The proposed assay demonstrates good selectivity and applicability for determination of AGs in real milk and honey samples. The Eu-MOF materials are further fabricated as fluorescent test papers for facile visual detection. The as-established ratio fluorescence platform offers a portable and economical way for rapid monitoring AGs residues in complex food samples.

Microwave-Enabled Fast Preparation of a Metal-Organic Framework Hybrid Membrane for Filtration-Enhanced Simultaneous Separation and Detection of Aflatoxin B1.

Mycotoxin contamination in food and the environment seriously harms human health. Sensitive and timely detection of mycotoxins is crucial. Here, we report a dual-functional hybrid membrane with absorptivity and responsiveness for fluorescent-quantitative detection of mycotoxin aflatoxin B1 (AFB1). A biomineralization-inspired and microwave-accelerated fabrication method was established to prepare a hybrid membrane with a metal-organic framework (MOF) loaded in high density. The MOF presented high efficiency in capturing AFB1 and showed fluorescence intensity alteration simultaneously, enabling a dual adsorption-response mode. Deriving from the inherent porous structure of the hybrid membrane and the absorptive/responsive ability of the loaded MOF, a filtration-enhanced detection mode was elaborated to provide a 1.67-fold signal increase compared with the conventional soaking method. Therefore, the hybrid membrane exhibited a rapid response time of 10 min and a low detection limit of 0.757 ng mL-1, superior to most analogues in rapidity and sensitivity. The hybrid membrane also presented superior specificity, reproducibility, and anti-interference ability and even performed well in extreme environments such as strong acid or alkaline, satisfying the practical requirements for facile and in-field detection. Therefore, the membrane had strong applicability in chicken feed samples, with a detection recovery between 70.6% and 101%. The hybrid membrane should have significant prospects in the rapid and in-field inspection of mycotoxins for agriculture and food.

Porphyrin-based covalent organic framework as oxidase mimic for highly sensitive colorimetric detection of pesticides.

A covalent organic framework-based strategy was designedfor label-free colorimetric detection of pesticides. Covalent organic framework-based nanoenzyme with excellent oxidase-like catalytic activity was synthesized. Unlike other artificial enzymes, porphyrin-based covalent organic framework (p-COF) as the oxidase mimic showed highly catalytic chromogenic activity and good affinity toward TMB without the presence of H2O2, which can be used as substitute for peroxidase mimics and H2O2 system in the colorimetric reaction. Based on the fact that the pesticide-aptamer complex can inhibit the oxidase activity of p-COF and reduced the absorbance at 650nm in UV-Vis spectrum, a label-free and facile colorimetric detection of pesticides was designed and fabricated. Under the optimized conditions, the COF-based colorimetric probe for pesticide detection displayed high sensitivity and selectivity. Taking fipronil for example the limit of detection was 2.7ng/mL and the linear range was 5-500,000ng/mL. The strategy was successfully applied to the detection of pesticides with good recovery , which was in accordance with that of HPLC-MS/MS. The COF-based colorimetric detection was free of complicated modification H2O2, which guaranteed the accuracy and reliability of measurements. The COF-based sensing strategy is a potential candidate for the sensitive detection of pesticides of interests.

A facile and efficient voltammetric sensor for marbofloxacin detection based on zirconium-based metal-organic framework UiO-66/nitrogen-doped graphene nanocomposite

Improper and persistent use of marbofloxacin (MAR) is prone to produce residues that deteriorate the surrounding environment and endanger our health. Hence, it is urgent to stablish a facile and efficient detection technique for the detection of MAR. Herein, a highly efficient electrochemical platform was constructed for sensitive determination of MAR using zirconium-based metal–organic framework (UiO-66)/nitrogen-doped graphene (NG) nanocomposites (UiO-66/NG). The surface morphology, crystalline phase, elemental composition, and electrochemical behavior of UiO-66/NG were characterized by various spectroscopic and electrochemical techniques. Owing to the synergistic interaction of UiO-66 MOFs and NG nanosheets, the UiO-66/NG exhibited remarkable catalytic activity for MAR oxidation. As consequently, the UiO-66/NG demonstrated a wide linear response range (0.01 − 10 μM), high sensitivity (1.80 μM μA−1 cm−2) and low detection limit (0.002 μM). The proposed UiO-66/NG/GCE demonstrated robust voltammetric responses even in the presence of excess potential interfering species and retained stable response signals for at least two weeks. More importantly, the proposed UiO-66/NG/GCE displayed highly consistent sensitivity toward MAR detection in both aquaculture water and milk matrices and PBS buffer, and achieved accurate and sensitive detection of MAR with good recovery. Together with its low cost and facile operation, the UiO-66/NG/GCE shows great prospects for trace detection of MAR from complex matrices.

Rapid and facile electrochemical detection and degradation of carbendazim in the spiked environmental trials using reduced graphene oxide/titanium dioxide-based sensor

This study aims to develop a rapid, facile, and sensitive sensor for electroanalytical carbendazim (CAR) detection. A novel and simple sensor was fabricated by incorporating a composite matrix of titanium dioxide nanoparticles (TiO2-NPs) with reduced graphene oxide (rGO) loaded carbon paste within a polytetrafluoroethylene (PTFE) tube for investigation. Characterization of the synthesized TiO2-NPs was conducted using SEM, XRD, and AFM techniques to assess their structural, morphological and functional features that could support understanding the electrocatalytic activity at the modified sensor (CPE/rGO/TiO2). Comparative analysis with the carbon paste electrode (CPE) revealed that CPE/rGO/TiO2 demonstrated sensitivity, achieving approximately a 6-fold higher detection current in CAR analysis. Cyclic voltammetry (CV), linear sweep voltammetry (LSV) and square wave voltammetry (SWV) approaches were employed for CAR's electrochemical detection and determination. The physicochemical attributes of the electrode activity were investigated under optimum experimental conditions, including electrolyte pH and accumulation time. The CPE/rGO/TiO2 exhibited a limit of detection of 7.66 nM, with a sensitivity of 1.08 µA.µM−1.cm−2 within a wide range of concentration linearity. The selectivity of CPE/rGO/TiO2 against interference metal ions with CAR was assessed. In real-time applications, the developed electrode was tested for the analysis of CAR in spiked soil and water samples, demonstrating significant detection capacity with good recovery. Moreover, the electrode exhibited stability across multiple measurements, highlighting CPE/rGO/TiO2 as a promising sensor for CAR detection.

Ultrasensitive electrochemical detection of bile acids via ZIF-67-MOF-derived CoNi(OH)x/CeO2/COOH-MWCNTs composite electrodes

Fast and ultra-sensitive assays are essential for the assessment of the efficacy of traditional Chinese medicines. Here, an ultrasensitive and rapid electrochemical detection of bile acid in traditional Chinese medicine using composite electrodes is presented. Cobalt-nickel hydroxide and cerium dioxide (CoNi(OH)x/CeO2) nanomaterials were synthesized in situ by a two-step reflux method with cobalt-containing metal–organic framework (ZIF-67), as precursor. It was ultrasonically complexed with carboxylated carbon nanotubes (COOH-MWCNTs) to form CoNi(OH)x/CeO2/COOH-MWCNTs composites, for facile direct detection of bile acids in traditional Chinese medicine. Characterization methods were used to verify the successful creation of the composite CoNi(OH)x/CeO2/COOH-MWCNTs, a material which demonstrated excellent electrochemical properties. The experimental results showed that the electrode responded well when bile acids, nicotinamide adenine dinucleotide, and 3α hydroxysteroid dehydrogenase were simultaneously present in the solution, and that the peak current had a good linear relationship (R2 = 0.988) with the concentration of bile acids (0.05–10.0 µM). The sensor has an outstanding detection limit of 1.0 nM, 2–3 orders of magnitude more sensitive than the concentration. Therefore, it can be used for rapid on-site detection of bile acids in real traditional Chinese medicines.

Copper(II) Driven Fluorescence switch-on Detection of Ovalbumin and GSH Using a Pyridoxal 5'-phosphate Derived Tetradentate Schiff Base and its Applications.

The facile detection of glutathione (GSH) and ovalbumin (OVA) is of great importance in biological research. Herein, a tetradentate Schiff base N, N'-bis(pyridoxal-5-phosphate)-o-phenylenediamine (L) obtained by condensing two moles of pyridoxal 5'-phosphate (PLP) with one mole of 1,2-phenylenediamine was employed for the fluorescence switch-on detection of GSH and OVA. When excited at 389nm, receptor L showed a weak emission at 454nm in an aqueous medium. The addition of GSH to the solution of L caused a significant fluorescence enhancement at 454nm. Amino acids (leucine, glycine, serine, tryptophan, homocysteine, alanine, methionine, arginine and proline) and albumins (bovine serum albumin and OVA) failed to alter the fluorescence profile of L. Receptor L can be applied to detect GSH down to 1.16 µM. However, the fluorescence emission of L was quenched upon the formation of the L-Cu2+ complex. The addition of GSH and OVA to the in-situ formed L-Cu2+ complex restored not only the fluorescence emission of L but also a noticeable fluorescence enhancement observed at 454nm. The decomplexation of L-Cu2+, along with the interaction of L with GSH and OVA is expected to suppress the conformational flexibility of L that enhanced the fluorescent intensity at 454nm. Using L-Cu2+ complex, the concentration of OVA and GSH can be detected down to 0.31 µM and 0.20 µM, respectively. Molecular docking and dynamics simulation were performed to analyze the binding mode, conformational flexibility and dynamic stability of the L-Cu2+-OVA complex. Finally, the analytical novelty of L-Cu2+ was examined by detecting GSH/OVA in real biological samples, such as human blood serum, urine, and egg white.

Cellulose Nanofiber Films with Gold Nanoparticles Electrostatically Adsorbed for Facile Surface-Enhanced Raman Scattering Detection.

Cellulose nanofiber (CNF) holds great promise in applications such as surface-enhanced Raman scattering (SERS), catalysis, esthesia, and detection. This study aimed to build novel CNF-based SERS substrates through a facile synthetic method. Citrate-reduced gold nanoparticles (AuNPs) were adsorbed on the cationized CNF surface due to electrostatic interactions, and uniform AuNPs@(2,3-epoxypropyl trimethylammonium chloride)EPTMAC@CNF flexible SERS substrates were prepared by a simple vacuum-assisted filtration method. The probe molecule methylene blue was chosen to assess the performance of the CNF-based SERS substrate with a sensitivity up to 10-9 M, superior signal reproducibility (relative standard deviation (RSD) = 4.67%), and storage stability (more than 30 days). Tensile strength tests indicated that the CNF-based films had good mechanical properties. In addition, CNF-based substrates can easily capture and visually identify microplastics in water. These results demonstrate the potential application of the flexible, self-assembled AuNPs@EPTMAC@CNF flexible SERS substrate for prompt and sensitive detection of trace substances.

Colorimetric sensor array for versatile detection and discrimination of model analytes with environmental relevance

In the current work, a rapid, simple, low-cost, and sensitive smartphone-based colorimetric sensor array coupled with pattern-recognition methods was proposed for the determination and differentiation of some organic and inorganic bases (i.e., OH−, CO32−, PO43−, NH3, ClO−, diethanolamine, triethanolamine) as model compounds. The sensing system has been designed based on color-sensitive dyes (Fuchsine, Giemsa, Thionine, and CoCl2) which were used as sensor elements. The color changes of a sensor array were observed by the naked eye. The color patterns were recorded using digital imaging in a three-dimensional (red, green, and blue) space and quantitatively analyzed with color calibration techniques. Distinctive colorimetric patterns for target bases via linear discriminant analysis (LDA) and hierarchical clustering analysis (HCA) were observed. The results indicated that the analytes related to each class (at the different concentration levels in the range of 0.001–1.0 mol L−1) were clustered together in the canonical discriminant plot and HCA dendrogram with high sensitivity and an overall precision of 85%. Furthermore, the first function factor of LDA correlated with the concentration of each target analyte in a correlation coefficient (R2) range of 0.864–0.996. These described procedures based on the colorimetric sensor array technique could be a promising candidate for practical applications in package technology and facile detection of pollutants.

Colorimetric Silver Ion Detection Based on Silver Metallization of Gold Nanorods

AbstractDespite the use of silver in various industries, this heavy metal can pose serious risks to living organisms and the environment. Therefore, the development of simple measurement strategies for detection of silver ions (Ag+) with high sensitivity is of great importance. In this research, gold nanorods (AuNRs) have been used as indicator element in colorimetric sensor, which provides the possibility of facile and visual detection of silver by forming gold@silver core‐shell nanostructures (Au@Ag NRs). The basis of this sensor is the metallization of silver on AuNRs through ascorbic acid (AA) as a reducing agent, which forms Au@Ag NRs. During this mechanism, Ag+ is converted to silver atom (Ago) in the presence of AA and the surface of AuNRs is coated by inducing metallization. Any changes in composition and dimensions of AuNRs will cause color changes in the detection solution and subsequently spectral changes. The obtained results showed a good correlation between silver concentration and probe response (λo–λ) in the range of 2.5 to 30.0 μmol L−1 with a detection limit of 1.3 μmol L−1. In addition, the evaluation of the sensor in water and soil samples showed that it has acceptable accuracy in detecting silver ions in real conditions.

Paper-based 2D configuration for the electrochemical and facile detection of paracetamol in wastewaters

Since 2020, human pharmaceuticals were included in the list of emerging contaminants from the UNESCO and their detection and elimination were incorporated in the 2030 Agenda for Sustainable Development Goal Targets. Among these, analgesic and antipyretic drugs are the most widely used drugs worldwide and, despite their advantages, unused or expired pharmaceuticals are a potential source of water pollution. Paracetamol is one of the most common drugs used for analgesic and antipyretic purposes and has been found to have a much higher concentration in water streams in many European countries. Considering that, an all-in-one paper-based 2 dimensional (2D) fluidic configuration, able to detect paracetamol, was developed in order to deal with environmental matrices without complex/expensive analytical procedures. An ad-hoc paper-based testing area, coupled with a channel was designed and wax-printed onto a porous filter paper. Successively three electrodes were screen-printed, and the whole system was applied for the detection of paracetamol in wastewaters (prior and after the filtration system) without pretreating the sample. In order to detect paracetamol with the easiest approach, the configuration of the paper-based device was optimized in terms of type of substrate used for printing, microfluidic paper strip length/width and combination of them in an integrated architecture, capable to detect paracetamol in the matrices tested in few seconds with a detection limit down to micromolar range, ca. 1 μM. The integrated device shown great promise for simple, fast, sensitive, and sustainable detection of paracetamol in its role of emerging contaminant, especially in the environmental matrices.

Robust Thiazole-Linked Covalent Organic Frameworks for Water Sensing with High Selectivity and Sensitivity.

The rational design of covalent organic frameworks (COFs) with hydrochromic properties is of significant value because of the facile and rapid detection of water in diverse fields. In this report, we present a thiazole-linked COF (TZ-COF-6) sensor with a large surface area, ultrahigh stability, and excellent crystallinity. The sensor was synthesized through a simple three-component reaction involving amine, aldehyde, and sulfur. The thiazole and methoxy groups confer strong basicity to TZ-COF-6 at the nitrogen sites, making them easily protonated reversibly by water. Therefore, TZ-COF-6 displayed color change visible to the naked eye from yellow to red when protonated, along with a red shift in absorption in the ultraviolet-visible diffuse reflectance spectra (UV-vis DRS) when exposed to water. Importantly, the water-sensing process was not affected by polar organic solvents, demonstrating greater selectivity and sensitivity compared to other COF sensors. Therefore, TZ-COF-6 was used to detect trace amounts of water in organic solvents. In strong polar solvents, such as N,N-dimethyl formamide (DMF) and ethanol (EtOH), the limit of detection (LOD) for water was as low as 0.06% and 0.53%, respectively. Even after 8 months of storage and 15 cycles, TZ-COF-6 retained its original crystallinity and detection efficiency, displaying high stability and excellent cycle performance.

Nanoribbons as advanced nanomaterials for facile detection and efficient removal of heavy metals: a comprehensive review

Nanoribbons as advanced nanomaterials for facile detection and efficient removal of heavy metals: a comprehensive review

Portable luminescent fiber- and glove-based nanosensor for multicolor visual detection of tetracycline in food samples.

Anintelligent fluorescent nanoprobe (lignite-CDs-Eu) was constructed by an effective and facile method based on lignite-derived carbon dots (CDs) and lanthanide europium ions (Eu3+), which exhibited high sensitivity, low detection limit (13.35nM) and visual color variation (from blue to red) under ultraviolet light towards tetracycline (TC) detection. Significantly, portable and economical sensors were developed using lignite-CDs-Eu immobilized fiber material of filter paper and wearable glove with the aid of colorextractingandimage processing application (APP) in the smartphone. Facile, fast and real-time visual detection of TC in food samples was realized. Moreover, logic gate circuit was also designed to achieve intelligent and semi-quantitative inspection of TC. To some extent, this study extended the cross-application of intelligent computer software in food analytical science, and provided a certain reference for the development of small portable detection sensors which were suitable for convenience and non-professional use in daily life.