Paint Samples Research Articles

Exploring purification methods to improve retrieval of collagenous binder residues from archeological murals

A comparison was conducted on five methods for purifying collagenous residues extracted from paint replicas. The bicinchoninic acid method was used to quantify proteins recovered by these purification methods, and the conductivity in purified solutions was monitored. Statistical analysis was carried out by multivariate analysis of variance (MANOVA). The effect of different purification processes upon the molecular structure of the retrieved proteins was characterized with the aid of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), ultraviolet (UV) absorption spectroscopy, and circular dichroism (CD) spectroscopy. The results showed that the five methods all had significant desalination effects, among which dialysis, ultrafiltration, and ethanol precipitation could achieve lower conductivity. The protein recovery rate of dialysis was remarkably higher than the rates of other methods. With the aging time of the paint replicas, the recovery rates of all purification methods showed a downward trend, with the advantage of dialysis becoming more and more remarkable. No significant differences were found in the molecular weight and microstructure of the residues retrieved by the five purification methods, indicating that the impacts of different purification processes on the microstructure of proteins / peptides are approximately the same. A total of 29 identified peptides (consisting of 18 unique ones) corresponding to rabbit collagen were successfully detected in a model sample using the improved pretreatment. This paper concluded that dialysis is a more promising purification method for archeological paint samples with a higher potential to retrieve more residues for subsequent analysis.

Rediscovering Gaspar de Figueroa: A Technical Examination of the Portrait of Friar Cristóbal de Torres, Archbishop of the New Kingdom of Granada

ABSTRACT Gaspar de Figueroa (c.1594-1658) was a prolific painter in seventeenth-century Santafé de Bogotá, New Kingdom of Granada (modern-day Colombia). The portrait of Cristóbal de Torres, painted in 1643, is one of the rare-signed examples of works by the artist that exist. This article focuses on the technical examination of the painting using well-established imaging techniques, fiber analysis, optical microscopy of paint sample cross-sections and SEM-EDX. The choice and handling of the materials and the painting's built up showed proficient knowledge of the craft, the appropriation and local adaptation of European painting techniques, and the collaborative character of the artist's painting practice. Emphasis is given to the color palette, which is rich in locally sourced, high-quality earths, including the unusual blue earth pigment vivianite, and red lake pigments. This paper comes at an opportune time as it coincides with the increasing art historical interest in the exhibition and research of Colonial Latin American Art. Moreover, it opens a broad avenue of research that promises to contribute to the understanding of Gaspar de Figueroa's technique, to lead to a better-established oeuvre for the artist and to a greater knowledge of the art of painting in the New Kingdom of Granada.

Sustainable inorganic pigments with high near-infra-red reflectance based on Fe3+ doped YAlO3 for high temperature applications

Non-toxic inorganic pigments based on the Fe(III)-doped YAlO3 with high near-infra-red (NIR) reflectance were synthesized by a modified Pechini method at 1200 °C. A complete solid solution in the YAl1−xFexO3 system (0 ≤x ≤ 1) was prepared, yielding a wide range of colourations from yellow to red, depending on the iron content.Good pigment stability was achieved in a commercial high temperature glaze, used in the ceramic industry to colour glazes on tiles. The pieces coated with the pigmented glazes reached NIR solar reflectance values between 43% and 32%. The temperature protection studies carried out with the glazes pigmented with YAl0.75Fe0.25O3 and YFeO3 compositions, conclude that the pigmented samples reduce the temperature of a building by 5 °C and 4 °C, respectively, in comparison to the unpigmented glaze.Thus, these pigments can be excellent candidates for used in high-temperature applications such as colouring ceramic high temperatures glazes, as well as cool pigments in walls or roofs of buildings.

An IoT-Enabled E-Nose for Remote Detection and Monitoring of Airborne Pollution Hazards Using LoRa Network Protocol.

Detection and monitoring of airborne hazards using e-noses has been lifesaving and prevented accidents in real-world scenarios. E-noses generate unique signature patterns for various volatile organic compounds (VOCs) and, by leveraging artificial intelligence, detect the presence of various VOCs, gases, and smokes onsite. Widespread monitoring of airborne hazards across many remote locations is possible by creating a network of gas sensors using Internet connectivity, which consumes significant power. Long-range (LoRa)-based wireless networks do not require Internet connectivity while operating independently. Therefore, we propose a networked intelligent gas sensor system (N-IGSS) which uses a LoRa low-power wide-area networking protocol for real-time airborne pollution hazard detection and monitoring. We developed a gas sensor node by using an array of seven cross-selective tin-oxide-based metal-oxide semiconductor (MOX) gas sensor elements interfaced with a low-power microcontroller and a LoRa module. Experimentally, we exposed the sensor node to six classes i.e., five VOCs plus ambient air and as released by burning samples of tobacco, paints, carpets, alcohol, and incense sticks. Using the proposed two-stage analysis space transformation approach, the captured dataset was first preprocessed using the standardized linear discriminant analysis (SLDA) method. Four different classifiers, namely AdaBoost, XGBoost, Random Forest (RF), and Multi-Layer Perceptron (MLP), were then trained and tested in the SLDA transformation space. The proposed N-IGSS achieved "all correct" identification of 30 unknown test samples with a low mean squared error (MSE) of 1.42 × 10-4 over a distance of 590 m.

47 Safe-by-Design Advanced Materials: A case Study on Paint Formulation

Abstract Paint formulations are complex mixtures of both dissolved and particulate components, both organic and inorganic. Amorphous silica nanoparticles are included to make the paint layer dirt-repellent. Over entire life cycle of the paints containing such silica nanoparticles, however, their complex multicomponent composition may raise several concerns as to their hazard when exposed to humans and environment, notably due to the potential release of the incorporated nano-objects. To mitigate such concerns, several Safe-by-Design target specifications can be performed to provide revised/modified paint formulations with reduced potential risk. Within EU H2020 funded project, HARMLESS (grant agreement 953183), a specific industrial case study focuses on worker exposure measurement at the industrial production site of silane modified silica nanoparticles and consumer exposure measurement during sanding of the painted surfaces containing such silica nanoparticles. First results indicate that the tested paint samples (with and without silica nanoparticles) have strong tendencies to generate airborne nano-objects during their sanding. However, the fraction of silica in the overall chemical composition of the airborne nano-objects is currently being investigated. A fraction of the dust generated during the paint sanding is being analysed for its hazard via advanced in vitro approaches combined with a battery of toxicological endpoint analyses. Based on the results, if the exposure concentration of silica nanoparticles is found to be exceeding its nano reference value (i.e. 40,000 cm-3 TWA) and exhibits deleterious biological impact, the size and surface of silica nanoparticles will be modulated accordingly by keeping an optimum balance between their functionality and risk

Preserving the Ephemeral: A Micro-Invasive Study on a Set of Polyurethane Scenic Objects from the 1960s and 1970s.

Among the innovative materials used by 20th-century artists, polyurethane (PUR) has been shown to be highly unstable, and therefore artworks made of it are now in need of careful conservation strategies. This study presents a multi-analytical investigation of PUR foam scenic objects originally made between the 1960s and 1970s during the Italian Arte Viva movement. The main components in the foam and additives were characterized through micro attenuated total reflectance infrared spectroscopy (μ-ATR-FTIR) and pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS). Painted samples were further investigated through μ-FTIR and Raman spectroscopy to define binders and pigments. The use of μ-ATR-FTIR in combination with evolved gas analysis-mass spectrometry (EGA-MS) allowed the variable conditions of the artworks to be assessed and attained some insights into the chemical processes responsible for aging. At the same time, morphological changes due to the degradation phenomena were recorded through optical (OM) and scanning electron microscopy (SEM). The detailed characterization of the PUR foam and painting materials was helpful in attaining some insights into harmful environmental parameters for the artworks, thus informing preventive conservation.

Using Artificial Intelligence to Identify Sources and Pathways of Lead Exposure in Children.

Sources and pathways of lead exposure in young children have not been analyzed using new artificial intelligence methods. To collect environmental, behavioral, and other data on sources and pathways in 17 rural homes to predict at-risk households and to compare urban and rural indicators of exposure. Cross-sectional pilot study. Knox County, Illinois, which has a high rate of childhood lead poisoning. Rural families. Neural network and K-means statistical analysis. Children's blood lead level. Lead paint on doors, lead dust, residential property assessed tax, and median interior paint lead level were the most important predictors of children's blood lead level. K-means analysis confirmed that settled house dust lead loadings, age of housing, concentration of lead in door paint, and geometric mean of interior lead paint samples were the most important predictors of lead in children's blood. However, assessed property tax also emerged as a new predictor. A sampling strategy that examines these variables can provide lead poisoning prevention professionals with an efficient and cost-effective means of identifying priority homes for lead remediation. The ability to preemptively target remediation efforts can help health, housing, and other agencies to remove lead hazards before children develop irreversible health effects and incur costs associated with lead in their blood.

Design, synthesis, and characterization of highly photostable Pigment Yellow 74 derivatives for painting applications

The present objective of this study was develop highly photostable novel Pigment Yellow 74 (P.Y. 74) derivatives. The structures of the synthesized compounds were confirmed by NMR, IR, and HRMS spectral analysis. From the NMR, and IR spectra, pigments exist in the hydrazone tautomeric form. Irradiating pigment samples with UV light allowed us to test their photostability in liquid and spin-coated films. The results revealed that the synthesized pigments PYA, PYB, and PYC have better photostability than the commercial P.Y. 74. The higher photostability of the synthesized pigment (PYA) is mainly due to the presence of strong intramolecular hydrogen bonding. The shifting of pivaloyl carbonyl stretching frequencies towards lower wavenumbers in the FT-IR spectra, as well as the pigment exhibiting sharp reflections in the powder XRD spectra, demonstrate this. The studied results provide insight into the synthesized PYA as a possible replacement to the commercial P.Y. 74 in the color industry.

Separation of Amino Acids, Dyes, and Pigments Using Novel Pressurized Circular TLC Assembly for Secure Medical Imaging Applications.

A novel pressurized flow system for circular thin-layer chromatography (PC-TLC) has been successfully established and employed for the separation of amino acids, dyes, and pigments for safe medical imaging applications. In this system, the mobile phase is applied to a regular TLC plate through the tube and needle of an intravenous infusion set. The needle was fused in a hole underneath the center of the plate, while the second side end of the tube was connected to a microburette containing the solvent. This new assembly proved itself better in terms of separation time (within 5 minutes) and controlled flow of the solvent and horizontal movement of analyte components over chromatograms with better separation and R f values (glutamine: 0.26, valine: 0.44, phenylalanine: 0.60, chlorophyll a: 0.52, chlorophyll b: 0.43, xanthophyll: 0.18, carotenoid: 0.97, and pheophytin: 0.60) when a number of samples of amino acids, dyes, and pigments were separated by the developed apparatus and the conventional TLC procedure. The developed method was found distinctly rapid, precise, and eco-friendly (less solvent consuming) as compared to traditional ascending TLC.

Algorithm for Automatic Generation of Oil Painting Guidance in Colleges and Art Culture Video Based on Intelligent Brush

This paper proposes a computer-generated algorithm for college oil painting style guidance and art culture video automatic generation with intelligent brushes. This paper proposes to use the tensor eigenvector value of the smart brush as the brush direction to draw multiple layers of input video frames to effectively simulate the fluid feel of Van Gogh's oil paintings. At the same time, an improved local illumination model is proposed. mapping technology to enhance the paint layering of drawn video frames. Firstly, the multispectral PCA spectral reconstruction algorithm is used to reconstruct the spectral reflectance of the oil painting surface, and then the image information and color information of the oil painting are reproduced; secondly, the combination of physical BRDF and multispectral images is used to reproduce the spatial information and color information of oil painting samples.

Maximum likelihood factor analysis for resolution of noisy smartphone based diffuse reflectance data from CdS pigments

This study aims to use multivariate chemometric methods such as principal component analysis (PCA), maximum likelihood common factor analysis (MLFA), and multivariate curve resolution alternating least squares (MCR-ALS) to analyze a designed data set and obtain an estimation of measurement error structure in the absence of replicates. For this purpose, we developed a smartphone-based diffuse reflectance spectrophotometer (smartDRS) with the advantage of being rapid, simple, and cost-effective in acquiring spectral information from the produced pigment samples based on a designed experiment. In our experimental design, the effects of different factors on the color of synthesized cadmium sulfide (CdS) pigment are investigated. DR spectral data from synthesized CdS samples were rapidly and successfully measured using the homemade device. The contribution of three forms (two crystalline and one amorphous) of CdS with three different spectra in each of the 16 synthesized pigment samples was illustrated and confirmed by using MLFA-MCR-ALS. Based on RGB values obtained from spectral information, the concentration profile of the brightest form of CdS was considered as a quantitative criterion of the whiteness of CdS samples and the response in the experimental design. The experimental design results showed pH, use of the furnace, and time for CdS drying as the main factors, in addition to a two-factor (Cd/S molar ratio × drying time) and a three-factor (pH × furnace × drying time) interactions are statistically significant on experimental design response. MLFA results also showed that independent noise in the measured diffuse reflectance data is heteroscedastic but not simply proportional to the signal intensities. This study shows the success of maximum likelihood-based multivariate analysis of diffuse reflectance spectral data from smartDRS for quantitatively investigating affecting factors on synthesized CdS color. Results from the application of PCA before MCR-ALS were considerably different from what was obtained from MLFA and MCR-ALS and were not in accordance with the previous reports.

The Archer and the Shield-Bearing Warrior

AbstractAt the Painted Coulee site (24JT86), pictographs depicting both atlatl and bow technology are present. We utilized plasma oxidation followed by accelerator mass spectrometry to directly radiocarbon date the organic material in two paint samples. A red painting of an anthropomorph with a shield and a possible atlatl in conflict with a fleeing person holding a bow was dated to 1790 ± 50 RCYBP (cal AD 120–390). Another red anthropomorph wearing snowshoes and holding a bow was dated to 1710 ± 45 RCYBP (cal AD 240–425). Radiocarbon dates for underlying oxalate minerals provided maximum ages for the paintings that are consistent with the direct ages. This early example of Plains Biographic rock art is significant because it illustrates a scene between a Late Archaic shield-bearing warrior with a possible atlatl and an anthropomorph with a bow and arrow at a time when bows first came into use on the Northwestern Plains.

Rapid determination of free sulfur dioxide in wine and cider by capillary electrophoresis

A novel method for the determination of “true” free sulfur dioxide (SO2) in wine and cider was developed using capillary electrophoresis with direct ultraviolet-visible spectrophotometric detection (CE-UV/vis). Free SO2 was measured in model solutions with different SO2-binding agents present (α-ketoglutarate, pyruvate, acetaldehyde, glucose, fructose, and malvidin-3-glucoside) as well as a variety of white and red wines and ciders. The CE method was compared to three conventional methods for measuring free SO2, the Ripper method, Aeration-Oxidation (AO), and pararosaniline by discrete analyzer (DA). While some statistically significant differences (p<0.05) were found between the four methods in unpigmented model solutions and samples, the values generally agreed. In the presence of anthocyanins in model solution and red wines, free SO2 values found by CE were significantly lower than the other three methods (p<0.05). The difference in values found by Ripper and CE correlated strongly with anthocyanin content (R2 = 0.8854) and even more strongly when accounting for polymeric pigments (R2 = 0.9251). The results in red ciders differed from those in red wines, while the CE measured significantly lower free SO2 values than the other three methods, the difference in free SO2 values measured by CE and Ripper correlated more closely with anthocyanin concentration (R2 = 0.8802) than absorbance due to bleachable pigment (R2 = 0.7770). The CE method was found to be rapid (4 min/injection), sensitive (LOD=0.5 mg/L, LOQ=1.6 mg/L free SO2 in wine, 0.8 and 2.8 mg/L, respectively, in cider), robust, and repeatable (average RSD = 4.9%) and did not suffer from the issue of over-reporting free SO2 in pigmented samples often observed with currently accepted methods.

The colors of the empire: Assessing techno-decorative innovations in local, hybrid and intrusive ceramic pigments within the Wari interaction spheres, Peru

Ancient empires developed diverse strategies of political and cultural domination in their conquered territories. One such strategy involved introducing imperially branded goods that reinforced a legitimizing ideology. The appearance of intrusive styles may be an indicator of political dominance; however, the introduction of new technologies is a stronger indicator of interpersonal engagement between people in the empire’s core and dominated regions. In this paper, we specifically focus on innovations in colors, pigments, and decoration of intrusive, local, and hybrid ceramic styles resulting from the interaction between the Wari Empire (600–1050 CE) of the Central Andes and local societies from the north and south coast of Peru. These innovations can be documented long after the Wari influence faded in each region. By integrating archaeological and archaeometric perspectives, we examine techno-decorative innovations among locally produced pottery within the imperial interaction spheres. This paper presents and compares the results of chemical and mineral analyses conducted on samples of pigments on decorated ceramics from the Valleys of Jequetepeque, Nasca, and Moquegua. Results indicate that Wari could have directly promoted the circulation of specific ceramic pigments that guaranteed a particular “Wari experience of color.” We argue that an inter-site approach to the study of colors, pigments, and decoration can better contribute to the understanding of politics and ceramic production relationships, religious syncretism, and cultural change in the Andean past.

An open-source biaxial tensile tester with automated pre-tensioning for mechanical studies of canvas paintings

The mechanical aspects of canvas painting conservation and the study of the effects of conservation treatments benefit greatly from quantifying the mechanical characteristics of the materials. However, this is seldom possible as only few labs have the necessary equipment. This paper presents the development of a biaxial tester to be used for samples of canvas paintings which exhibit orthotropic behavior under biaxial loads. The machine was built as the first step of ongoing Ph.D. research on the mechanics of canvas paintings. An effort was made to create a system that is easy to assemble, with parts that are easy to source and with an overall cost well below the commercial units available. The control software includes the function of automated pre-tensioning to improve the accuracy of the measurement. Our broader purpose here is to make an easy-to-replicate machine available to help conservators and conservation scientists perform tensile tests to make informed choices in materials science.

Chromium Concentrations in Automotive Paints from Retail Stores in Kenya

Chromium (Cr) is among the heavy metals that are added to automotive paints to provide protection against corrosion and reflective properties. However, exposure to hexavalent chromium Cr(VI), which is the toxic form of Cr is associated with adverse health effects such as lung cancer. The study, therefore, assessed Cr levels in the automotive paints commonly used by spray painters in informal settings in Nairobi City. Chromium concentrations were determined in triplicates in the three sets of automotive paint samples in red, blue and green colours. The same samples were also used for the determination of lead content and the findings of the study were published elsewhere. The automotive paint samples were procured from 8 formal and informal retail stores. The Cr concentrations was also analyzed using Atomic Absorption Spectrophotometry. The mean ± standard deviation (SD) of Cr levels obtained from informal retail shops ranged from 120.5±10.6 to 2771.9±35.6 parts per million (ppm). On the contrary, those from the formal retail stores were significantly lower (p &lt; 0.05), and were in the range of 39.3±7.0 to 461.9±11.1 ppm. The Cr levels in automotive paints varied greatly across different colours and retail shops. Substantial levels were observed in almost all paint samples purchased from the informal retail shops except one retail shop. The elevated Cr levels in various colours of automotive paints used by spray painters in the informal sector call for a comprehensive assessment of Cr in these settings along with health-driven policies to address related health impacts.

Contributory science reveals insights into metal pollution trends across different households and environmental media

Heavy metals are prevalent in urban settings due to many legacy and modern pollution sources, and are essential to quantify because of the adverse health effects associated with them. Of particular importance is lead (Pb), because there is no safe level of exposure, and it especially harms children. Through our partnership with community scientists in the Marion County (Indiana, United States) area (n = 162 households), we measured Pb and other heavy metal concentrations in soil, paint, and dust. Community scientists completed sampling with screening kits and samples were analyzed in the laboratory via x-ray fluorescence by researchers to quantify heavy metal concentrations, with Pb hazards reported back to participants. Results point to renters being significantly (p ≤ 0.05) more likely to contain higher concentrations of Pb, zinc (Zn), and copper (Cu) in their soil versus homeowners, irrespective of soil sampling location at the home. Housing age was significantly negatively correlated with Pb and Zn in soil and Pb in dust across all homes. Analysis of paired soil, dust, and paint samples revealed several important relationships such as significant positive correlations between indoor vacuum dust Pb, dust wipe Pb, and outdoor soil Pb. Our collective results point to rental status being an important determinant of metal pollution exposure in Indianapolis, with housing age being reflective of both past and present Zn and Pb pollution at the household scale in dust and soil. Thus, future environmental pollution work examining renters versus homeowners, as well as other household data such as home condition and resident race/ethnicity, is imperative for better understanding environmental disparities surrounding not just Pb, but other heavy metals in environmental media as well.

‘The brighter the worse’: Lead content of commercially available solvent-based paints intended for residential use in Pakistan

Background: Environmental pollution and exposure to lead (Pb) through household paint continue to be a great concern, especially for low- and middle-income countries (LMICs). Methods: We measured the Pb levels of solvent-based paints commercially available in Karachi, Pakistan. We visited major markets and collected commonly available brands of paint, sampling the yellow, red, and white colors of each. The paint samples’ Pb content was measured using inductively coupled argon plasma atomic emission spectrometry (ICP-AES). Results: Of the 60 analyzed paint samples, 24 (40%) contained Pb levels of &gt;100 ppm (beyond the legal limit in Pakistan), with a maximum of 97,000 ppm (dry weight). Sixteen (76.2%) of the 21 yellow paints (range: 5,100–97,000 ppm, IQR: 36,900 ppm), seven (37.0%) of the 19 red paints (range: 220–1,800 ppm, IQR: 255 ppm), and one (5%) of the 20 white paints (870 ppm) contained Pb levels of &gt;100 ppm. Of the 60 paints, 45 were produced by domestic Pakistani companies (51% exceeding the limit) and 15 by multinational companies (7% exceeding the limit). Conclusions: Although Pakistani regulations have restricted Pb content in paints to &lt;100 ppm since 2017, these regulations are poorly implemented, as highlighted by this study. We therefore recommend that paint manufacturers comply with national standards and internationally recommended Pb limits to ensure the health and safety of children and other populations in Pakistan.

Spectroscopic Investigation of a Color Painting on an Ancient Wooden Architecture from the Taiping Heavenly Kingdom Prince Dai’s Mansion in Jiangsu, China

This research sheds light on the analysis of pigments and adhesives applied on a color painting on wooden architecture in Taiping Heavenly Kingdom Prince Dai’s mansion, located in Changzhou, Jiangsu Province in China. Four samples were collected from the painting above the building beam in the mansion, and the samples were analyzed and identified using a series of techniques, including polarized light microscopy (PLM), scanning electron microscope coupled with an energy-dispersive X-ray spectroscopy (SEM-EDS), micro-Raman spectroscopy (m-RS) and Fourier-transform infrared spectroscopy (FTIR). The results indicate that the red, black, blue, and green pigments were identified to be cinnabar, ivory black, indigo, and phthalocyanine green, respectively. The green pigment was inferred to be a lately repainted pigment based on its production age, suggesting that this ancient building had been refurbished or repaired. Given the good stability and visual effect of this green pigment, it is suggested to be used in future conservation processes. The pyrolysis-gas chromatography/mass Spectrometry (Py-Gc/Ms) results indicate that glue containing protein was used as a binder for the pigment samples, and that walnut oil might have been applied to the wooden architecture as a primer before painting. Our findings can well inform curators and conservators of the selection of appropriate restoration materials if necessary, and also provide data support for conservation of similar ancient buildings in southern China.

Photoluminescence Sensing of Soluble Lead in Children’s Crayons Using Perovskite Nanocrystal In Situ Growth on an Aluminum Hydroxide Layer

In this study, a fluorescence sensing approach for lead ion (Pb2+) was developed using in situ growth of methylamine lead bromine (MAPbBr3) perovskite on an aluminum hydroxide (Al(OH)3) thin layer. The Al(OH)3 thin layer could be obtained on a glass slide by liquid phase deposition and is of a large specific surface area and insoluble in water. After sulfhydryl functionalization, the Al(OH)3 thin layer reveals effective adsorption and excellent enrichment ability to Pb2+ and is additionally used as the substrate for the in situ growth of lead halogen perovskite. The fluorescence sensing of Pb2+ could be realized by the fluorescence intensity of lead halogen perovskite on the Al(OH)3 layer. The linear relationship between the fluorescence intensity and the concentration of Pb2+ was found in the range from 80 to 1500 mg/kg. The detection limit of Pb2+ is found to be 40 mg/kg, which is lower than the maximum permission of lead residue in student products (90 mg/kg) stipulated by the National Standard of the People's Republic of China (GB21027-2020). After being grinded and pre-treated, soluble lead in watercolor paint and crayon samples can be extracted by the sulfhydryl functionalization Al(OH)3 layer, then lead halogen perovskite can be generated in situ on the layer to achieve the fluorescence sensing for the determination of soluble lead in the samples.