Visible Color Change Research Articles

A new multifunctional phenanthroline-derived probe for colorimetric sensing of Fe2+ and fluorometric sensing of Zn2.

A new phenanthroline derivativebearing imidazole group, (2-(3,5-di(pyridin-4-yl)phenyl)-1-p-tolyl-1H-imidazo[4,5-f][1,10]phenanthroline) (1), has been devised. 1can be used as a multifunctionalprobe exhibiting a highly sensitive colorimetric response to Fe2+ and a selectively ratiometric fluorescent response to Zn2+in a buffer-ethanol solution. The absorption enhancement accompanied by a visual color change from colorless to red upon addition of Fe2+, makes 1a suitable naked-eye sensor for Fe2+. Moreover, 1displayed a Zn2+-induced red-shift of emission (44 nm) showing a color change from blue to light cyan under a 365-nm UV lamp. Its practical imaging applicability for intracellular Zn2+was confirmed in HeLa cells using a confocal microscope. The improved emission properties and cell imaging capability would provideanew approach forfluorescencesensationfor Zn2+.

Smartphone-enabled colorimetric immunoassay for deoxynivalenol based on Mn2+-mediated aggregation of AuNPs

Deoxynivalenol (DON) is a common mycotoxin in food that mainly pollutes grain crops and feeds, such as barley, wheat and corn. DON has caused widespread concern in the field of food and feed safety. In this study, a colorimetric immunoassay was proposed based on the aggregation of gold nanoparticles (AuNPs) due to the decomposition of Mn2+ from gold-coated manganese dioxide (AuNP@MnO2) nanosheets. In this study, 2-(dihydrogen phosphate)-l-ascorbic acid (AAP) was hydrolyzed by alkaline phosphatase (ALP) and converted to ascorbic acid (AA). Then, AuNP@MnO2 was reduced to Mn2+ and AuNPs aggregation occurred. Using the unique optical characteristics of AuNPs and AuNP@MnO2, visible color changes realized simple detection of DON with high sensitivity and portability. With increasing DON content, the color changed more obviously. To quantitatively detect DON, pictures can be taken and the blue value can be read by a smartphone. The detection limit (Ic10) of this method was 0.098 ng mL−1, which was 326 times higher than that of traditional competitive ELISA, and the detection range was 0.177–6.073 ng mL−1. This method exhibited high specificity with no cross-reaction in other structural analogs. The average recovery rate of DON in corn flour samples was 89.1 %–110.2 %, demonstrating the high accuracy and stability of this assay in actual sample detection. Therefore, the colorimetric immunoassay can be used for DON-related food safety monitoring.

Pleurotus extract-mediated selenium and zinc nanoparticles exhibited improved yield of biofortified fruit bodies.

The current study was aimed for the generation of Pleurotus extracellular extract-mediated selenium and zinc-oxide nanoparticles (NPs). The Pleurotus djamor (PD) and Pleurotus sajor-caju (PSC) extracts were incubated with different concentrations of sodium selenate and zinc acetate to yield BioSeNPs and BioZnONPs. The NPs formation led to visual color change (brick-red and white for Se and Zn nanosols, respectively). The synthesized NPs were spherical with size of 124 and 68nm and 84 and 91nm for PD and PSC BioSeNPs and BioZnONPs respectively. The UV absorbance peaks were recorded at 293.2 and 292.2nm and 365.9 and 325.5nm for BioSeNPs and BioZnONPs derived from PD and PSC respectively. FT-IR spectroscopy indicated specific functional group adoration on metal-based NPs. On supplementation in straw, these NPs improved the fruit body yield besides enhancing their protein and Se/ Zn contents. These biofortified mushrooms could be potential dietary supplement/ nutraceutical.

In Vitro Evaluation of Surface Roughness and Color Variation after Two Brushing Protocols with Toothpastes Containing Different Whitening Technologies

The aim was to evaluate the effect of different whitening toothpastes on the enamel surface roughness and color variation. Twenty-four molars were sectioned and divided into eight groups (n = 3) considering the following two factors under study: toothpaste type (Colgate® Total Original, Oral B® 3D White Luxe Perfection, Curaprox® Black is White, and Signal® White Now) and brushing protocol (short- and long-term). Surface roughness was examined by atomic force microscopy (AFM), and color change (ΔE) was measured using the CIE L*a*b* system. Data were statistically analyzed using comparative parametric tests at a 5% significance level. In the short-term protocol, only the Signal® White Now toothpaste increased surface roughness (p = 0.038) compared to the Colgate® Total Original group. No significant differences (p > 0.05) were observed in surface roughness in the long-term protocol. Regarding color variation, no statistically significant differences (p > 0.05) were observed in either protocol. Overall, the whitening toothpastes did not affect enamel surface roughness or color, except for Signal® White Now, which caused increased roughness in the short-term protocol. However, all toothpastes induced a visual change in color.

Probing the potential of mercury removal by covalently immobilized phycobiliproteins onto the surface of chitosan beads

Mercury emissions represent a significant risk to the environment and human health. Mercury is persistent and can circulate in the environment for thousands of years, which is why treating this toxic metal is important. Chitosan polymer is easily obtainable, and it has good mercury adsorption characteristics. This study aimed to improve its capabilities to absorb mercury by immobilizing phycobiliproteins (PBPs) onto the surface of chitosan beads (chitosan–PBPs). Phycobiliproteins, light-harvesting proteins from algae and cyanobacteria, have several industrially essential applications. These proteins can bind heavy metals with high affinities. Protein extracts obtained from both Arthrospira platensis, with C-phycocyanin (C-PC) as the primary protein, and Porphyra yezoensis, with R-phycocyanin (R-PC) and R-phycoerythrin (R-PE) as the dominant PBPs, were covalently immobilized onto chitosan beads. Beads with immobilized PBPs were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Binding analysis showed that, on average, each chitosan bead weighed 20 mg and immobilized 63.54 μg of PBPs from Spirulina and 44.12 μg of PBPs from Porphyra. Immobilized proteins were still in their native state, with no visible color change months after immobilization. Chitosan–PBPs and chitosan alone were tested for mercury adsorption at pH 4 and pH 7 by atomic absorption spectroscopy. The tested concentration range of mercury was from 1 to 70 ppm. Affinity, calculated using Henry's binding isotherm, of chitosan–PBPs for mercury was twice as much higher at both pH values than chitosan alone. Furthermore, chitosan-PBP beads were able to absorb more mercury than chitosan alone. These results showed that the covalent immobilization of PBPs onto chitosan improves its mercury adsorption characteristics and creates a more efficient eco-friendly adsorbent to potentially remove mercury ions in the tested concentration range from polluted waters.

Sprayable Diacetylene-Containing Amphiphile Coatings for Visual Detection of Gas-Phase Hydrogen Peroxide

Colorimetric chemical sensing of target gases, such as hydrogen peroxide vapors, is an evolving area of research that implements responsive materials that undergo molecule-specific interaction, resulting in a visible color change. Due to the intuitive nature of an observable color change, such sensing systems are particularly desirable as they can be widely deployed at low cost and without the need for complex analytical instrumentation. In this work, we describe our development of a new spray-on sensing material that can provide a colorimetric response to the presence of a gas-phase target, specifically hydrogen peroxide vapor. By providing a cumulative response over time, we identified that part per million concentrations of hydrogen peroxide vapor can be detected. Specifically, we make use of iron chloride-containing formulations to enable the catalysis of hydrogen peroxide to hydroxyl radicals that serve to initiate polymerization of the diacetylene-containing amphiphile, resulting in a white to blue color transition. Due to the irreversible nature of the color change mechanism, the cumulative exposure to hydrogen peroxide over time is demonstrated, enabling longitudinal assessment of target exposure with the same coatings. The versatility of this approach in generating a colorimetric response to hydrogen peroxide vapor may find practical applications for environmental monitoring, diagnostics, or even industrial safety.

Achieving Smart Photochromics Using Water-Processable, High-Contrast, Oxygen-Sensing, and Photoactuating Thiazolothiazole-Embedded Polymer Films.

Water-soluble dipyridinium thiazolo[5,4-d]thiazole (TTz) compounds are incorporated into inexpensive poly(vinyl alcohol) (PVA)/borax films and exhibit fast (<1 s), high-contrast photochromism, photofluorochromism, and oxygen sensing. Under illumination, the films change from clear/yellow TTz2+ to purple TTz•+ and then blue TTz0. The contrast and speed of the photochromism are dependent on the polymer matrix redox properties and the concentration of TTz2+. The photoreduced films exhibit strong, near-infrared light (1000-1500 nm) absorbances in addition to visible color changes. Spectroscopic ellipsometry was used to establish the complex dielectric function for the TTz2+ and TTz0 states. Incorporating non-photochromic dyes yields yellow-to-green and pink-to-purple photochromism. Additionally, when illuminated, reversible photoactuation occurs, causing mechanical contraction in the TTz-embedded films. The blue film returns to its colorless state via exposure to O2, making the films able to sense oxygen and leak direction for smart packaging. These films show potential for use in self-tinting smart windows, eyeglasses, displays, erasable memory devices, fiber optic communication, and oxygen sensing.

Nanofiber-reinforced self-healing polysaccharide-based hydrogel dressings for pH discoloration monitoring and treatment of infected wounds

The escalating global health concern arises from chronic wounds induced by bacterial infections, posing a significant threat to individuals. Consequently, an imperative exist for the development of hydrogel dressings to facilitate prompt wound monitoring and efficacious wound management. To this end, pH-sensitive bromothymol blue (BTB) and pH-responsive drug tetracycline hydrochloride (TH) were introduced into the polysaccharide-based hydrogel to realize the integration of wound monitoring and controlled treatment. Polysaccharide-based hydrogels were formed via a Schiff base reaction by cross-linking carboxymethyl chitosan (CMCS) on an oxidized sodium alginate (OSA) skeleton. BTB was used as a pH indicator to monitor wound infection through visual color changes visually. TH could be dynamically released through the pH response of the Schiff base bond to provide effective treatment and long-term antibacterial activity for chronically infected wounds. In addition, introducing polylactic acid nanofibers (PLA) enhanced the mechanical properties of hydrogels. The multifunctional hydrogel has excellent mechanical, self-healing, injectable, antibacterial properties and biocompatibility. Furthermore, the multifaceted hydrogel dressing under consideration exhibits noteworthy capabilities in fostering the healing process of chronically infected wounds. Consequently, the research contributes novel perspectives towards the advancement of intelligent and expeditious bacterial infection monitoring and dynamic treatment platforms.

Reliable ratiometric colorimetric monitoring of dopamine in practice based on the catalytic signal amplification of nano CeO2/CuO modified carboxylated chitosan

To reliably monitor dopamine (DA), a common neurotransmitter, a kind of nano CeO2/CuO modified carboxylated chitosan nanozyme (CeO2/CuO@CC) was constructed under microwave-assisted conditions. The proposed CeO2/CuO@CC exhibited superior synergistic- enhancement oxidase-like activity, with high specific surface area and superior stability. It could accelerate the oxidization of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into blue oxTMB in the air. What’s more, the presence of trace DA could exclusively change the enzyme-like activity of CeO2/CuO@CC, accompanied with visual color changes from blue to colorless. Under the optimized conditions, there expressed double ratiometric linear relationships between lg(A652/A285)/lg(A370/A285) and cDA, with a large linear range between 6.0 × 10−9 and 1.0 × 10−5 M of DA. When applied for visual detection of DA in real samples, the detection limit was low to 2.0 × 10−9 M with RSD % less than 4.14 %. The mechanisms for enhanced oxidase-mimic activity of CeO2/CuO@CC and its selective detection of DA were proposed. This work will offer an insight to design efficient nanozyme for visual detection of bio-analytes in practice.

A novel 1,3-diazepine-based fluorescent probe for highly selective detection of Hg2+

A novel 1,3-diazepine based fluorescent probe for Hg2+ has been successfully synthesized and characterized. Comprising a furan and pyridine, the probe L1 is a blue-emitting 1,3-diazepine derivative, which transforms into an imine form with high fluorescent yellow-emitting under alkaline conditions. Fluorescence quench of the probe in ethanol was observed with the addition of Hg2+ aqueous in the presence and absence of other metal ions, with a visible color change from colorless to yellow, and this fluorescence quench can be observed in a wide pH range of 3–11. An important feature for this probe is its high selectivity towards mercury ions for the aqueous-phase detection of Hg2+ over the other competitive metal ions, making the “naked-eye” detection of mercury ions possible.

Chromogenic Detection of the Organophosphorus Nerve Agent Simulant DCP Mediated by Rhodium(II,II) Paddlewheel Complexes.

Organophosphorus nerve agents (OPNAs) pose a great threat to humanity. Possessing extreme toxicity, rapid lethality, and an unassuming appearance, these chemical warfare agents must be quickly and selectively identified so that treatment can be administered to those affected. Chromogenic detection is the most convenient form of OPNA detection, but current methods suffer from false positives. Here, nitrogenous base adducts of dirhodium(II,II) acetate were synthesized and used as chromogenic detectors of diethyl chlorophosphate (DCP), an OPNA simulant. UV-vis spectrophotometry was used to evaluate the sensitivity and selectivity of the complexes in the detection of DCP. Visual limits of detection (LOD) for DCP were as low as 1.5 mM DCP, while UV-vis-based LODs were as low as 0.113 μM. The dirhodium(II,II) complexes were also tested with several potential interferents, none of which produced a visual color change that could be mistaken for OPNA response. Ultimately, the Rh2(OAc)4(1,8-diazabicyclo[5.4.0]undec-7-ene)2 complex showed the best combination of detection capability and interferent resistance. These results, when taken together, show that dirhodium(II,II) paddlewheel complexes with nitrogenous base adducts can produce instant, selective, and sensitive detection of DCP. It is our aim to further explore and apply this new motif to produce even more capable OPNA sensors.

Spatially confining copper atom in flowerlike-CoFe hydroxides for smartphone-based ratiometric colorimetric dual-mode detection of nitrite

Great progress in nanozyme catalysis for distinct catalytic reactions have been made. However, more current nanozyme-induced sensing platforms are depended on oxidase-like nanozymes with multienzymatic catalytic behavior, which can affect the determination accuracy and reliability. Designing high active and stable advanced nanozymes for enzyme-like catalysis remains a huge challenge for analytic chemistry. Herein, a three-atom site catalyst of CoFeCu hydroxide nanozyme is rationally prepared for constructing sensing platform by utilizing oxidase-like catalytic activity. The CoFeCu nanozyme can mimic the behavior of oxidase by trigging O2 into O2·− via its highly dispersed metal active sites, which exhibits good oxidase-like activities with of 2.22 mM and of 3.69 × 10−8 M·s−1 toward 3, 3′, 5, 5′-tetramethylbenzidine (TMB). Specifically, the elaborate doping of low content Cu leads to higher catalytic activity and adequate detection sensitivity. Interestingly, with the addition of nitrite, a redox and diazotized reaction can be induced to generate visual color change from blue to yellow, resulting in the nitrite level-related ratio variation for the absorbance intensity at 665 and 450 nm. Besides, to the realize the demand of point-of-care monitor of nitrite, a portable sensor was built containing a dark box by a UV lamp and an intelligent smartphone. In the colorimetry-smartphone modes, the linear ranges of nitrite are 1–290, and 3.3–250 μM, with related detection limits of 0.9, and 2.96 μM, respectively. This strategy was further used to detect nitrite in river water with outstanding results with the dual mode. Therefore, the proposed dual-mode detection approach provides promising potential for self-house monitor of nitrite, which will greatly improve the analysis efficiency and large-scale determination in human life quality.

All-in-one smartphone imaging for visual immunobiosensing of cancer biomarker using electronic gyro-centrifuge and nanozyme

Integrated functionality that combines recognition elements and sensors on a single platform to provide real-time detection capabilities for fifth-generation biosensors is considered one of the dominant tools for addressing point-of-care testing in the community today. Inspired by gyroscope and smartphone-based sensors, we developed a portable and low-cost immunobiosensor for high-throughput detection of cancer-related markers. The main testing process was divided into two parts: blood sample preprocessing based on an electronic gyroscope and signal reading based on nanozyme and smartphone. The feasibility of a commercial electronic gyroscope for serum acquisition from whole blood samples was evaluated. In addition, PtCd nanoclusters (PtCd NCs) were used as excellent peroxidase-like nanozymes to trigger the target signal conversion of the immunosensor. PtCd NCs were able to catalyze the conversion of H2O2 to ·OH, which rapidly oxidized the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) substrate to the blue Oxidized-TMB (oxTMB). Naked eye visible obvious color change and the RGB values of the color metrology system could also be read by smartphone. Prostate-specific antigen (PSA) as a model biomarker was used to validate the utility of an integrated immunoassay system to enable early cancer screening through localization of RGB values. This work focuses on convenient blood sample preprocessing and simplified serologic cancer screening steps to develop an efficient and cost-effective immunoassay platform for community and on-site point-of-care testing (POCT) in resource-limited settings.

Ultra-small nano CeO2/CuO doped carboxylated chitosan fibers for high-performance oxidase-mimic visual monitoring of S2− and Fe2+ in agricultural products

To improve the sensitivity and selectivity for S2− and Fe2+ detection in complex agricultural products, ultra-small nano CeO2/CuO doped carboxylated chitosan fibers (CeO2/CuO CCF) was constructed under microwave-assisted conditions. Not only did CeO2/CuO CCF possess suitable BET specific surface area, superior stability and synergistic-enhancement oxidase-like activity, trace S2− or Fe2+ could selectively change its oxidase-like activity accompanying with visible color changes. Under the optimized conditions, there express specific double ratiometric colorimetric linear relationships between lg(A729/A343)/lg(A415/A343) and cS2− or cFe2+ with large linear ranges. When applied for visual monitoring of S2− and Fe2+ in real agricultural products, the detection limits were low to 3.5 × 10−9 mol·L−1 and 9.4 × 10−8 mol·L−1 respectively, far below the permitted values in drinking water by World Health Organization. The mechanisms for synergistic-enhancement oxidase-like activity for CeO2/CuO CCF to selectively recognize S2− and Fe2+ were proposed. This work will provide an efficient way for visual monitoring of multiple analytes in complex agricultural products.

Physical Compatibility Between Intravenous Magnesium Sulfate and Potassium or Sodium Phosphate in a Pediatric Intensive Care Unit.

Objective:To evaluate the physical compatibility between intravenous magnesium sulfate and potassium and sodium phosphate, a common electrolyte intravenous supplementation in pediatric intensive care units. Study design: Magnesium sulfate was mixed separately with potassium phosphate and sodium phosphate at ratios of 1:1, 1:4, and 4:1. Binary mixtures were prepared, in triplicate and under sterile conditions, by permuting the order of addition. The undiluted pure drugs were used as controls for possible sequence effects. Visual changes, turbidity, and pH were assessed immediately after mixing (baseline) and at 4 and 24 hours. Two observers performed visual changes by naked-eye visual inspection in order to search visible haze, particulate matter, gas formation, or color change. Turbidity was measured by nephelometry and incompatibility was defined as an increase of ≥0.5 nephelometric turbidity units (NTU) from baseline. pH was measured using a portable pH meter and incompatibility was defined as a variation of >1 pH unit during the observation period. Results: None of the admixtures exhibited visual changes or significant variations in turbidity (increases of ≥0.5 in nephelometric turbidity units) or pH (changes of >1 unit) during the observation period and neither compared with baseline. Conclusion: In this study, no visual changes were observed, and turbidity and pH evaluated by instrumental methods remained within acceptable limits and showed no significant variations from baseline, therefore no physical incompatibility between magnesium sulfate and potassium or sodium phosphate was found.

Schiff base functionalized dialdehyde starch for enhanced removal of Cu (II): Preparation, performances, DFT calculations

Dialdehyde starch modified by 2-hydrazinopyridine (HYD-DAS) based on the reaction of dialdehyde starch (DAS) and 2-hydrazinopyridine was synthesized and characterized by FT-IR spectra, element analysis and SEM. HYD-DAS can efficiently adsorb Cu (II) ion to demonstrate visual color changes from yellow to dark brown in aqueous solutions. The influence on HYD-DAS to Cu (II) adsorption including pH value of solution, isotherm, kinetics, thermodynamics and possible mechanism had also been examined. Batch experiments indicate that HYD-DAS's to Cu (II) adsorption reaches equilibrium within 250 min, and its adsorption capacity and rate are 195.75 mg/g and 98.63 %, respectively. Moreover, HYD-DAS to Cu (II) adsorption remains robust and underscoring after five cycles to exhibit good selectivity and reusability. Kinetics studies suggest the absorption process follows a quasi-second-order with isotherms aligning to the Langmuir monolayer model, and thermodynamics reveals that it is a spontaneous endothermic nature of adsorption. Based on the analyses of XPS and DFT calculations, a possible mechanism for HYD-DAS to Cu (II) adsorption is that Cu (II) combined with nitrogen atoms from Schiff base and hydrazine pyridine ring in HYD-DAS.

Development, characterization and application of colorimetric active packaging based on soy protein isolate, trehalose and Oxalis triangularis extract

Colorimetric active packaging based on soy protein isolate (SPI)/trehalose (TRE) and Oxalis triangularis extract (OTE) was developed for monitoring pork spoilage and preserving Actinidia arguta. The formation of intermolecular hydrogen bonds among TRE, OTE, and the SPI matrix resulted in a more compact film structure and improved mechanical, barrier and water resistance properties. The addition of OTE greatly increased the antibacterial and antioxidant activities of the films. The stability of the films improved due to their dense network structure and good barrier and antioxidant capacity. Among all samples, SPI films containing both TRE and OTE (ST-OTE) exhibited the best barrier and mechanical properties after 45 days of storage and maintained a high level of antioxidant activity after heating and UV irradiation. SPI-OTE and ST-OTE films showed good pH sensitivity and responsiveness and exhibited visible color changes during the monitoring of pork spoilage. Compared to the control group, ST-OTE effectively prolonged the storage period of A. arguta.

Hymenaea courbaril resin-mediated gold nanoparticles as catalysts in organic dyes degradation and sensors in pharmaceutical pollutants

In this study, green synthesis of gold nanoparticles (AuNPs) using aqueous extract from Hymenaea courbaril resin (HCR) is reported. The successful formation, functional group involvement, size, and morphology of the subject H. courbaril resin mediated gold nanoparticles (HCRAuNPs) were confirmed by Ultra Violet-Visible (UV–vis) spectroscopy, Fourier-Transform Infrared spectroscopy (FTIR), and Transmission Electron Microscopy (TEM) techniques. Stable and high yield of HCRAuNPs was formed in 1:15 (aqueous solution: salt solution) reacted in sunlight as indicated by the visual colour change and appearance of surface Plasmon resonance (SPR) at 560 nm. From the FT-IR results, the phenolic hydroxyl (–OH) functional group was found to be involved in synthesis and stabilization of nanoparticles. The TEM analysis showed that the particles are highly dispersed and spherical in shape with average size of 17.5 nm. The synthesized HCRAuNPs showed significant degradation potential against organic dyes, including methylene blue (MB, 85 %), methyl orange (MO, 90 %), congo red (CR, 83 %), and para nitrophenol (PNP, 76 %) up to 180 min. The nanoparticles also demonstrated the effective detection of pharmaceutical pollutants, including amoxicillin, levofloxacin, and azithromycin in aqueous environment as observable changes in color and UV–Vis spectral graph.

Highly Selective and Scalable Molecular Fluoride Sensor for Naked-Eye Detection.

Fluoride is widely present in nature, and human exposure to it is generally regarded as inevitable. High levels of fluoride intake induce acute and chronic illnesses. To reduce potential harm to the general public, it is essential to create selective fluoride detectors capable of providing a colorimetric response for naked-eye detection without the need for sophisticated equipment. Here, we report a one-pot synthesis of four different diaminomaleonitrile-derived Schiff base sensors. The terephthalaldehyde adduct provided a strong color change visible to the naked eye at a F- concentration level as low as 2 ppm. From the evaluation against other anions, such as CN-, I-, Br-, Cl-, NO3-, PO43-, OAc-, and HSO4-, the molecular sensor displayed a visible color change exclusively upon exposure to fluoride, underscoring exceptional selectivity. As a key intermediate for understanding the mechanism, HF2- was confirmed by 19F nuclear magnetic resonance. Theoretical calculations suggested a deprotonation-triggered bathochromic shift brought about by the unique electronic structure of the sensor. Furthermore, the simple synthetic protocol from economically accessible materials allowed for the preparation of the compound on a large scale, rendering it a highly practical visual fluoride sensor.

Fabricating a photochromic Schiff base into a wearable cellulose sensor and a smart textile for ultraviolet radiation monitoring outdoors

A dual-channel photochromic Schiff base HBA is reported herein, which undergoes a reversible tautomerism in response to UV exposure, showing visible changes in both color and fluorescence. The spectral behavior, fatigue resistance, sensitivity are studied. The quantification of photochromic fluorescence/color change is solved by applying color spaces and chromatic aberration. HBA is further fabricated into low-cost wearable sensor and smart textile, enabling visual feedback under UV radiation. It demonstrates a low-costing platform for naked-eye-based dosimetry of outdoor UV radiations, providing an early warning for excessive UV exposure.