The Effect of Cigarettes Smoke on the Color and Properties of a Silicone for Maxillofacial Prostheses.

Although deterioration of silicone maxillofacial prostheses is severely accentuated in smoking patients, the phenomenon has not been systematically studied. To address a gap in the literature concerning the stability of maxillofacial prostheses during service, in this contribution, the effect of cigarette smoke on the aspect and physical properties of M511 silicone elastomer was evaluated. The aspect, surface, and overall properties of the silicone material, pigmented or not, were followed by AFM, color measurements, FTIR, water contact angle measurements, TGA-DTG and DSC, hardness and compression stress-strain measurements. The types of the contaminants adsorbed were assessed by XRF, ESI-MS, MALDI-MS, and NMR spectral analyses. Important modifications in color, contact angle, surface roughness, local mechanical properties, and thermal properties were found in the silicone material for maxillofacial prostheses after exposure to cigarettes smoke. The presence of lead, nicotine, and several other organic compounds adsorbed into the silicone material was emphasized. Slight decrease in hardness and increase in Young's modulus was found. The combined data show important impact of cigarette smoke on the silicone physical properties and could indicate chemical transformations by secondary cross-linking. To our knowledge, this is the first study making use of complementary physical methods to assess the effect of cigarette smoke on the aspect and integrity of silicone materials for maxillofacial prostheses.

Coomassie Brilliant Blue G for Smart Colorimetric Determination of the Ionic Surfactants in Triton X-100 Solutions.

The conditions for the smart colorimetric determination of cetylpyridinium chloride and sodium dodecyl sulfate by reaction with Coomassie brilliant blue G (CBBG) have been proposed. The nature of the absorption and fluorescence spectra of aqueous solutions of CBBG as a function of acidity has been investigated. A variety of reagent forms and associations with ionic surfactants have been demonstrated. The composition of the associates formed in the CBBG-cationic surfactant system has been established. The increase in the analytical signal of the cationic surfactant and the stabilization of the colloid-chemical state of the system during reactions in the organized medium of the nonionic surfactant Triton X-100 has been demonstrated. These effects are realized through association in premicellar solutions and as a result of the solubilization of components in Triton X-100 micellar solutions. The addition of long-chain cationic surfactants to the reagent occurs with the replacement of the heteroatom proton. The absorption of CBBG-cationic surfactant associates solutions increases with the length of the cationic surfactant hydrocarbon chain. Ethanol additives decrease the aggregation of CBBG. The technique of cationic surfactant determination has been tested in the analysis of the pharmaceutical. The results show that the simplicity of analytical signal registration with satisfactory correctness and acceptably high sensitivity of determination is an advantage of the developed technique.

Fluorescent and colorimetric dual-mode detection of Cu2+ based on carbon dots.

A fluorescent and colorimetric dual-mode strategy based on carbon dots (CDs) was rationally designed for sensitive determination of Cu2+. Green fluorescent CDs with high absolute quantum yield of 72.9% were synthesized by facile one-step hydrothermal treatment of triethylenetetramine and Rose Bengal. Cu2+ could trigger the oxidative and chromogenic reaction of p-phenylenediamine (PPD) to generate chromogenic PPDox, accompanied by the fluorescence quenching of the CDs. The quenching mechanism was identified as the inner filter effect between PPDox and CDs. Therefore, a colorimetric/fluorescent dual-mode detection method for Cu2+ recognition was constructed. The limits of detection for Cu2+ were 4.14 µM and 1.28 µM for colorimetric and fluorescent mode, respectively. In addition, this method had achieved satisfactory results in the detection of Cu2+ in real serum samples.

An ultrasensitive dual-mode stagey for 17ß-estradiol assay: Photoelectrochemical and colorimetric biosensor based on a WSe2/TiO2-modified electrode coupled with nucleic acid amplification.

BACKGROUND: The abuse of 17ß-estradiol(E2) has aroused wide concern in environmental and biomedical fields, which severely affects the endocrine function of human and animals. Therefore, an ultrasensitive and accurate assay of E2 is critically important. Traditional chromatography or immunoassay techniques exhibited good sensitivity and selectivity, but expensive instruments and antibodies may pose cost and stability issues, as well as difficulties in meeting on-site detection requirements. Ultrasensitive, reliable, and on-site detection of E2 at trace level remains a challenge. Hence, developing a simple, ultrasensitive assay to simultaneously achieve accurate detection and rapid visual analysis of E2 is extremely crucial. RESULTS: We developed a versatile dual-mode photoelectrochemical (PEC) and colorimetric biosensor based on isothermal nucleic acid amplification strategy for the ultrasensitive and accurate detection of E2. The method modified titanium dioxide (TiO2) with tungsten selenide (WSe2) nanoflowers to synthesize WSe2/TiO2 heterostructures as a substrate for signal amplification and nanoprobe modification. Isothermal nucleic acid amplification strategy has been proven to be a powerful tool for strong signal amplification. The presence of a target triggered the nucleic acid amplification reaction, and produced a large amount of tDNA that competed with G-quadruplex immobilized on the electrode surface. The remaining G-quadruplex/hemin catalyzed the 4-chloro-1-naphthol (4-CN) to form biocatalytic precipitation (BCP) and ABTS-H2O2 chromogenic reaction, thus, the dual-mode platform was capable of achieving PEC-colorimetric ultrasensitive detection based on the catalytic activity of G-quadruplex/hemin DNAzyme. Within optimal conditions, the dual-mode biosensor exhibited a remarkable detection limit as low as 0.026 pM. SIGNIFICANCE: Benefiting from the superior performance of WSe2/TiO2 and the power signal amplification of isothermal nucleic acid amplification strategy, this aptasensor achieved the ultrasensitive detection of E2. The independent transmission paths of photoelectrochemical and colorimetric provide mutual support and flexible switching, significantly enhancing the overall sensitivity and accuracy of the detection strategy, which can meet the needs for E2 precise quantification and rapid on-site detection.

Colorimetric detection of furin based on enhanced catalytic activity of G-quadruplex/hemin DNAzyme.

BACKGROUND: Rapid and sensitive colorimetric detection methods are crucial for diseases diagnosis, particularly those involving proteases like furin, which are implicated in various conditions, including cancer. Traditional detection methods for furin suffer from limitations in sensitivity and practicality for on-site detection, motivating the development of novel detection strategies. Therefore, developing a simple, enzyme-free, and rapid colorimetric analysis method with high sensitivity for furin detection is imperative. RESULTS: Herein, we have proposed a colorimetric method in this work for the first time to detect furin, leveraging the assembly of G-quadruplex/hemin DNAzyme with enhanced catalytic activity. Specifically, a peptide-DNA conjugate (PDC) comprising a furin-recognition peptide and flanking DNA sequences for signal amplification is designed to facilitate the DNAzyme assembly. Upon furin treatment, PDC cleavage triggers a cyclic catalytic hairpin assembly reaction to form the complementary double-stranded structures by hairpin 1 (HP1) and hairpin 2 (HP2), bringing the G-quadruplex sequence in HP1 closer to hemin on HP2. Moreover, the resulting G-quadruplex/hemin DNAzymes exhibit robust peroxidase-like activity, enabling the catalysis of the colorimetric reaction of ABTS2- for furin detection. Our method demonstrates high sensitivity, rapid response, and compatibility with complex sample matrices, achieving a detection limit as low as 1.1 pM. SIGNIFICANCE: The DNAzyme reported in this work exhibits robust catalytic activity, enabling high sensitivity and good efficiency for the detection. By eliminating the requirement for exogenous enzymes, our approach enables visual furin detection without expensive instrumentation and reagents, promising significant utility in biomedical and clinical diagnostic applications. Given the various design of peptide sequence and the programmability of DNA, it can be readily applied to analyzing other useful tumor biomarkers.

Polyoxometalate-based nanozyme with laccase-mimicking activity for kanamycin detection based on colorimetric assay.

As a kind of aminoglycoside antibiotics, kanamycin (KAN) is widely applied to animal husbandry and aquaculture. However, the abuse of KAN causes the large-scale discharge of it into rivers, lakes and groundwater, which threatens environmental safety and human health. Therefore, it is imperative to develop a method that is applicable to detect KAN in an efficient and accurate way. The colorimetric method based on enzymes provides a feasible solution for the detection of organic pollutants. However, the extensive application of natural enzymes is constrained by high cost and low stability. Herein, a polyoxometalate-based nanozyme, namely [H7SiW9V3O40(DPA)3]·4H2O (SiW9V3/DPA) (DPA = dipyridylamine), is synthesized. As a low-cost nanozyme with high stability compared to natural enzymes, SiW9V3/DPA performs well in laccase-mimicking activity. It can be used to induce chromogenic reaction between 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AP), which generates red products. With the addition of KAN, the color fades. That is to say, KAN can be detected with colorimetric assay in the concentration range 0.1 to 100 µM with high selectivity and low limit of detection (LOD) of 6.28 µM. Moreover, SiW9V3/DPA is applied to KAN detection in lake and river water and milk with satisfactory results. To sum up, polyoxometalate-based nanozyme is expected to provide a promising solution to the detection of organic pollutants in the aquatic environment.

"Shock kidney-like Appearance": Objective evaluation of renal color changes in hemorrhagic shock deaths.

Severe bleeding due to various traumatic injuries can cause hemorrhagic shock, which is difficult to diagnose using forensic medicine. Therefore, we defined the difference in color between the renal cortex and medulla observed in hemorrhagic shock deaths as "shock kidney-like appearance (SKLA)" and digitally analyzed the color difference with a digital camera and color analysis software. The aim of this study was to develop and evaluate a method for objectively determining SKLA and improve the accuracy of forensic diagnosis. We examined the kidneys of 122 cases (83 males and 39 females; average age, 64.8 years) autopsied at our facility. Using Image J, we analyzed the color of the cortex and medulla from photographs of bisected kidneys. We defined the color difference between the cortex and medulla in the L*a*b* color space as cortical-medullary color difference and performed a comparative analysis between the hemorrhage and control groups. Significant differences were observed in ΔL* and Δa* values between the two groups (p < 0.05 and p < 0.001, respectively). Analysis of Δa* values showed that the cortex was less reddish than the medulla in the hemorrhage group. The cutoff value for determining SKLA was set at Δa* = -1.33 (sensitivity, 0.79; specificity, 0.81; AUC, 0.859). Traditional evaluations of color rely on subjective assessments, which raise issues of reliability and reproducibility. This study successfully overcame the limitations of subjective evaluation by objectively assessing cortical-medullary color difference in the kidneys. Our results represent an important step towards improving the objectivity of color evaluations.

Low-cost, immediate, general-purpose, and high-throughput (LIGHt) smartphone colorimetric screening assay for water-soluble protein.

An efficient and rapid method for the detection of total soluble protein in tobacco leaves, utilizing a smartphone-based colorimetric approach has been developed. The proposed low-cost, immediate, general-purpose, and high-throughput (LIGHt) smartphone colorimetric screening assay integrates commercially available microplates, enabling on-site, high-throughput screening of tobacco leaf quality. The study involves preparing protein standard solutions and constructing standard curves using both spectrophotometric and smartphone-based methods. The LIGHt smartphone colorimetry yielded an average relative standard deviation of 10.6 %, a limit of detection of 2 µg/mL, and an average recovery of 93 %. The results demonstrated a comparable performance between intensities from the blue channel and the absorbance values in reflecting protein concentrations, validating the feasibility of utilizing smartphone colorimetry for protein concentration determination. Our approach demonstrates the potential for practical implementation in the field, providing a cost-effective and user-friendly solution for rapid quality assessment in the tobacco industry. The LIGHt smartphone colorimetry enhances quality control practices in the tobacco sector and offers a promising tool for on-site production quality testing in various industries, such as fruits and vegetables.

Thermal measurement of erythema across skin tones: Implications for clinical identification of early pressure injury.

AIM: To assess the effectiveness of thermography, colorimetry, and oximetry at detecting temperature changes after erythema induction across diverse skin tones in healthy adults. MATERIALS AND METHODS: Erythema was induced at the forearm and ulnar head (UH) using a cupping device. Temperature via thermal image, erythema value via colorimeter, and oxygen saturation via oximeter were collected immediately and 5-10 min (delayed) after cupping at both sites. RESULTS: At the forearm, the delayed timepoint was significantly warmer than baseline. At the UH, the immediate timepoint was significantly colder than baseline. Erythema increased at both timepoints and both locations. The correlation between temperature change and erythema change was weak. Change in temperature did not differ between skin tone groups. The Intermediate Low Eumelanin skin tone group had more change in erythema compared to the Intermediate Mid (i.e., darkest) skin tone group immediately after cupping at the UH and at the delayed timepoint at the forearm. CONCLUSIONS: This study observed differences in the change of erythema across skin tones but did not observe differences in temperature across skin tones. Given high variability in results, it is premature to conclude thermal imaging works equally well across all skin tones. Further research is necessary to validate the effectiveness of thermal imaging in diverse populations. Results suggest visual erythema may be a problematic indicator as less erythema was consistently noted in participants with dark skin tones. The potential of technology to increase our ability to detect erythema warrants further investigation.

Engineering the nanozyme hydrogel beads by polyvinyl alcohol/chitosan encapsulation with recyclable and sustainable catalytic activity for visual analysis of hydrogen peroxide.

BACKGROUND: Hydrogen peroxide (H2O2) plays a vital role in human health and have been regarded as a crucial analyte in metabolic processes, redox transformations, foods research and medical fields. Especially, the long-time and excessive digestion of H2O2 may even cause severe diseases. Although conventional instrumental methods and nanozymes-based colorimetric methods have been developed to accomplish the quantitative analysis of H2O2, the drawbacks of instrument dependence, cost-effectiveness, short lifespan, non-portable and unsustainable detection efficacies will limit their applications in different detection scenarios. RESULTS: Herein, to address these challenges, we have proposed a novel strategy for nanozyme (RuO2) hydrogel preparation by the solid support from cross-linked polyvinyl alcohol (PVA) and chitosan (CS) to both inherit the dominant peroxidase-like (POD) activity and protect the RuO2 from losing efficacies. Taking advantages from the hydrogel, the encapsulated RuO2 were further prepared as the regularly spherical beads (PCRO) to exhibit the sustainable, recyclable, and robust catalysis. Moreover, the intrinsic color interferences which originated from RuO2 can be avoided by the encapsulation strategy to promote the detection accuracy. Meanwhile, the high mechanical strength of PCRO shows the high stability, reproducibility, and cyclic catalysis to achieve the recyclable detection performance and long lifetime storage (40 days), which enables the sensitively detection of H2O2 with the detection limit as lower to 15 µM and the wide detection linear range from 0.025 to 1.0 mM. SIGNIFICANCE: On the basis of the unique properties, PCRO has been further adopted to construct a smartphone detection platform to realize the instrument-free and visual analysis of H2O2 in multi-types of milk and real water samples through capturing, processing, and analyzing the RGB values from the colorimetric photographs. Therefore, PCRO with the advanced detection efficacies holds the great potential in achieving the portable and on-site analysis of targets-of-interest.

An ultrasensitive dual-mode aptasensor for patulin based on the upconversion particles and G-Quadruplex-hemin DNAzyme.

Patulin (PAT) is a mycotoxin-produced secondary metabolite that can contaminate foods, causing toxic effects on animal and human health. Therefore, for the first time, we have constructed a "turn-on" dual-mode aptamer sensor for PAT using oleic acid-coated upconversion nanomaterials (OA-UCNPs) and G-Quadruplex-hemin DNAzyme (G4-DNAzyme) as fluorescent and colorimetry probes. The sensor employs aptamers binding to PAT as recognition elements for specific molecule detection. Mxene-Au can be used as a biological inducer to assist OA-UCNPs in controlling fluorescence intensity. In addition, colorimetric signal amplification was performed using the trivalent G4-DNAzyme to increase detection sensitivity and reduce false positives. Under optimal conditions, the dual-mode aptasensor has a detection limit of 5.3 pg mL-1 in fluorescence and 2.4 pg mL-1 in colorimetric methods, respectively, with the wider linear range and limit of detection (LOD) of the colorimetric assay. The combination aptasensor can detect PAT with high sensitivity and high specificity and has broad application prospects in the field of food safety detection.

Phosphatase-mimicking Zr@PDA nanozyme with excellent dispersion stability for the detection of fructose 1,6-diphosphate.

Zr4+-doped polydopamine (Zr@PDA) nanozyme with phosphatase-like activity was synthesized by a one-pot hydrothermal method for the first time. Compared with previous representative phosphatase-mimicking nanozymes (i.e., CeO2 NPs, ZrO2 NPs and UiO-66), Zr@PDA not only exhibited higher dispersion stability in water, but also higher catalytical efficiency. Kcat/Km of Zr@PDA is 35 and 12 times that of UiO-66 and ZrO2 NPs, respectively, which would endow the Zr@PDA-based analytical methods with high sensitivity. As a demonstration, a novel colorimetric method based on Zr@PDA nanozyme was developed for sensitive detection of the drug fructose 1,6-diphosphate. The linear range is 1-15 µM with a detection limit as low as 0.38 µM.

Laccase-mimicking activity of octahedral Mn3O4 nanoparticles and fluorescence of carbon dots as dual-mode signals for the specific detection of arsenic(V) in environmental water samples.

The detrimental growth of water pollutants such as heavy metals has become a life-threatening problem in the modern era. Challenges remain in the development of rapid and accurate methods for detecting pentavalent arsenic [As(V)] in environmental water. The octahedral Mn3O4 nanoparticles (NPs) did not display excellent laccase-mimicking catalytic activity, whereas the adsorbed As(V) on the surface significantly enhanced the catalytic activity. Meanwhile, the quinone imine generated from the substrates 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AAP) catalyzed by octahedral Mn3O4 NPs further quenched the carbon dots fluorescence. Thus, it is possible to establish a fast and accurate dual-mode sensor for detecting As(V). The developed dual-mode method of As(V) detection has good sensitivity and selectivity. The limit of detection for As(V) in colorimetric mode is 6.96 µg·L-1, whereas in the fluorescent mode, it is as low as 2.56 µg·L-1. Moreover, the detection data obtained by the dual-mode method can be validated by each other, thereby ensuring the dependability of the sensing system. The constructed dual-mode method with merits of sensitivity, speed and accuracy can offer a powerful tool for As(V) detection in environmental water. Furthermore, the application of laccase-mimicking activity in dual-mode detection provides new strategies for other environmental hazard detection.

Colorimetric sensors constructed with one dimensional PtNi nanowire and Pt nanowire nanozymes for Hg2+ detection.

BACKGROUND: In recent years, environmental pollution has attracted widespread global attention. Among them, environmental problems caused by heavy metal pollution pose a serious threat to human health and ecosystems. Mercury is a common heavy metal pollutant with high toxicity and wide distribution. Excessive intake of Hg2+ can cause permanent and severe damage to the nervous system, respiratory system, and kidneys in the human body. Therefore, developing both accurate and fast detection methods for Hg2+ is of great significance. RESULTS: A sensitive Hg2+ colorimetric sensor is designed based on PtNi nanowires (NWs) and Pt NWs with peroxidase-mimetic activity. PtNi NWs and Pt NWs catalyze the reaction of 3,3', 5,5'-tetramethylbenzidine (TMB) with hydrogen peroxide (H2O2) to produce blue oxidized TMB (oxTMB). The specific interaction of Pt-Hg significantly inhibits the peroxidase-mimetic activity of PtNi NW and Pt NW nanozymes, resulting in a lighter blue color. It is worth noting that compared with specific activity (SA) of Pt NWs (3.31 U/mg), PtNi NWs own superior SA (10.43 U/mg), which inevitably leads to a wider linear range of Hg2+ analysis (1 nM-200 µM) and a lower detection limit (0.6748 nM) for PtNi NWs-based colorimetric sensor, versus linear range (4 nM-5 µM) and LOD of 1.198 nM for Pt NWs-based colorimetric sensor, which are far below the Hg2+ threshold (10 nM) for drinking water set by the US Environmental Protection Agency. SIGNIFICANCE: The two nanozyme colorimetric sensors have been successfully used for the evaluation of Hg2+ in complex river water and tap water. Due to the advantages of simple operation, fast response, and high sensitivity, colorimetric sensors have broad application prospects in environmental monitoring.

A Versatile pH-Dependent Fluorometric, Colorimetric, and Electrochemical Sensor for H2S Monitoring in Water.

Hydrogen sulfide (H2S) is a colorless, foul smelling, toxic substance that can be found in water bodies and waste waters, especially in occupational susceptible environments, and can lead to harmful effects in humans at higher concentrations. An H2S monitoring probe NNAP is synthesized, which displays pH-dependent electrochemical, colorimetric, and fluorescence responses. NNAP functions as a fluorometric sensor at pH 7.4, with a limit of detection (LOD) of 0.70 mM, and as a colorimetric sensor at pH 12, where visible color changes are discernible to the naked eye, with an LOD of 4.28 mM. Additionally, it demonstrates utility in electrochemical sensing at pH 2, with a LOD of 2.5 mM. Furthermore, NNAP-coated paper strips have been successfully utilized for real-time H2S monitoring applications.

Implementation of green-assessed nanotechnology and quality by design approach for development of optical sensor for determination of tobramycin in ophthalmic formulations and spiked human plasma.

A fast eco-friendly colorimetric method was developed for the determination of Tobramycin in drug substance, ophthalmic formulations, and spiked human plasma using silver nanoparticles optical sensor. Even though tobramycin is non-UV-visible absorbing, the developed method is based on measuring the absorbance quenching of silver nanoparticles resulting from the interaction with tobramycin. Different factors affecting the absorbance intensity were studied as; silver nanoparticle concentration, pH, buffer type, and reaction time using quality by design approach. Validation of the proposed method was performed according to ICH guidelines and was found to be accurate, precise, and sensitive. The linearity range of tobramycin was 0.35-4.0 µg/mL. The optical sensor was successfully applied for the determination of Tobramycin in ophthalmic formulations and spiked human plasma without pre-treatment. Additionally, the binding between Tobramycin and PVP- capped silver nanoparticles was studied using molecular docking software. The method was assessed and compared to colorimetric reported methods for the green character using Green Analytical Procedure Index (GAPI) and Analytical GREEnness calculator (AGREE) tools and found to be greener.

Indicator displacement-based colorimetric assay for dibutyl phthalate in pharmaceutical products with titanium(IV)-pyridylazo resorcinol (PAR).

Taking advantage of the competitive binding affinity towards Ti(IV) between 4-(2-pyridylazo) resorcinol (PAR) and phthalate, a simple indicator displacement (ID)-based colorimetric assay was designed for indirect determination of a well-known phthalic acid ester, dibutyl phthalate (DBP). The indicator PAR and Ti(IV) formed a purplish-red-colored Ti(IV)-PAR complex (λmax = 540 nm) at a 1:1 ratio. In the presence of pre-hydrolyzed DBP, colorless complex formation of phthalate ion (emerging from alkaline hydrolysis of DBP) with Ti(IV) resulted in a hypsochromic shift in absorbance maximum, accompanying a color change from purplish-red to yellowish-orange (λmax = 390 nm) by the release of PAR from Ti(IV)-PAR system. Based on this mechanism, the linear response range of the system for DBP was found to lie between 0.16 and 0.37 mmol L-1 with an experimental detection limit of 11.6 µmol L-1. The recommended Ti(IV)-PAR system was successfully applied to DBP-containing pharmaceutical products (as real sample) after a simple clean-up process for removing possible water-soluble interferents. The analytical results obtained from the recommended method (by applying the standard addition approach) and the reference liquid chromatography-tandem mass spectrometric (LC-MS/MS) method were statistically compared using DBP-extract of the drug samples. Consequently, a simple and selective colorimetric ID strategy was proposed for the analysis of DBP in pharmaceuticals for the first time.

A smartphone-assisted portable on-site detection system for organophosphorus pesticides in vegetables and fruits based on all-in-one paper-based sensors: 2,2-Dichlorovinyl dimethyl phosphate as a model.

The improper use of organophosphate pesticides (OPs) can lead to residue posing a serious threat to human health and environment. Therefore, the development of a simple, portable, and sensitive detection method is crucial. Herein, a bioenzyme-nanozyme-chromogen all-in-one paper-based sensor was synthesized. Initially, the Ce/Zr-MOF with peroxidase-like activity was grown on filter paper (FP) using in-situ solvent thermal method, resulting in Ce/Zr-MOF@FP. Subsequently, the AChE-ChO-TMB system was immobilized onto Ce/Zr-MOF@FP using biocompatible gelatin, which enhanced cascade catalysis efficiency through the proximity effect. Based on the inhibition principle of OPs on AChE, we integrated this sensor with Python-based image recognition algorithm to achieve detection of OPs. Using 2,2-dichlorovinyl dimethyl phosphate (DDVP) as a model of OPs, it has good detection performance with a detection limit of 0.32 ng mL-1 and a recovery rate range of 95-107%. The potential for on-site detection of DDVP residues in vegetables and fruit samples is highly promising.

A 3D-Printed Do-It-Yourself ELISA Plate Reader as a Biosensor Tested on TNFα Assay.

Simple analytical devices suitable for the analysis of various biochemical and immunechemical markers are highly desirable and can provide laboratory diagnoses outside standard hospitals. This study focuses on constructing an easily reproducible do-it-yourself ELISA plate reader biosensor device, assembled from generally available and inexpensive parts. The colorimetric biosensor was based on standard 96-well microplates, 3D-printed parts, and a smartphone camera as a detector was utilized here as a tool to replace the ELISA method, and its function was illustrated in the assay of TNFα as a model immunochemical marker. The assay provided a limit of detection of 19 pg/mL when the B channel of the RGB color model was used for calibration. The assay was well correlated with the ELISA method, and no significant matrix effect was observed for standard biological samples or interference of proteins expected in a sample. The results of this study will inform the development of simple analytical devices easily reproducible by 3D printing and found on generally available electronics.

Imaging Based Techniques Combined with Color Measurements for the Enhancement of Medieval Wall Paintings in the Framework of EHEM Project.

(1) Background: This paper illustrates an innovative methodological approach chosen to study and map the colors of the medieval wall painting of Santa Maria Antiqua in the Roman Forum, one of the pilot sites of the EHEM project (Enhancement of Heritage Experiences: The Middle Ages). Digital Layered Models of Architecture and Mural Paintings over Time). (2) Methods: Two methods were employed to gather information about colors and mapping. Specifically, colorimetry was utilized for spot measurements, and hypercolorimetric multispectral imaging (HMI) was employed to map the same colors sampled through colorimetry. (3) Results: Chromatic data for all colors in the wall paintings were obtained in the CIELAB color space. Additionally, chromatic similarity maps were generated using the innovative HMI system, a multispectral imaging technique capable of obtaining color data information through advanced calibration software named SpectraPick® (Version 1.1). This comprehensive approach facilitates a thorough understanding of color characteristics and distribution. (4) Conclusions: The color measurements and mapping represent significant advancements in the interpretation of medieval wall paintings, which are often fragmentary and stratigraphically complex. This research sheds new light on the colors used and enhances our understanding of the original appearance of the iconographic patterns. Furthermore, it enables the reconstruction of colors that closely resemble the originals.