Colorimetric Changes Research Articles

A fluorescence probe with targeted mitochondria was developed for detecting H2O2 in vitro and vivo

We designed and developed the probe P-1 for detecting H2O2. The probe can selectively detect H2O2 with colorimetric change. In addition, the combination of portable test strips with a smartphone platform provided great convenience for on-site and visual detection of H2O2 with satisfactory sensitivity and reliability. The P-1 can image exogenous and endogenous H2O2 in cells and distinguish cancer cells and normal cells by fluorescence image of H2O2 and flow cytometry. Meanwhile, the P-1 probe has been successfully applied to monitor H2O2 levels of tumor in mice, and the results showed the level of H2O2 in tumor tissue increased significantly. Therefore, P-1 provided a potential chemical tool to understand pathological and physiological mechanisms of diseases by imaging H2O2.

Construction of an ultrasensitive hypochlorite fluorescent probe based on a novel chromophore fragmentation strategy

The excess intake of hypochlorite (ClO−) in the human body and excessive emission in wastewater can pose serious health risks and environmental pollution. Therefore, it is vital to develop an efficient method for detecting ClO− in foodstuff and water. In this work, we reported a lactam-fused aza-BODIPY (LAB1) for ultrasensitive ClO− detection based on novel chromophore fragmentation strategy for the first time. It exhibited distinct advantages of good selectivity, high sensitivity, fast response (60 s) and low detection limit of 9.65 nM. The sensing mechanism revealed LAB1 core was fragmented by ClO−, leading to significantly colorimetric and ratiometric fluorescence changes. As a result, 320 nm blue-shift in absorption maximum (from green to colorless) and 340 nm blue-shift in emission maximum (from dark to bright blue) allowed for visual detection by the naked eyes. The potential applicability of LAB1 for ClO− detection with satisfactory recovery in the real samples (tap water and lake water) and vegetables (spinach, lettuce, Chinese cabbage, bean sprouts), and fluorescence “turn on” imaging in mung bean sprout were demonstrated. In addition, LAB1-loaded test paper was suitable for semi-quantitative scanning ClO− analysis by using color recognition APP in a smartphone. Therefore, this work highlights a promising approach based on novel sensing mechanism for monitoring ClO− in food samples.

Real-Time Signal Analysis with Wider Dynamic Range and Enhanced Sensitivity in Multiplex Colorimetric Immunoassays Using Encoded Hydrogel Microparticles.

The simultaneous quantification of multiple proteins is crucial for accurate medical diagnostics. A promising technology, the multiplex colorimetric immunoassay using encoded hydrogel microparticles, has garnered attention, due to its simplicity and multiplex capabilities. However, it encounters challenges related to its dynamic range, as it relies solely on the colorimetric signal analysis of encoded hydrogel microparticles at the specific time point (i.e., end-point analysis). This necessitates the precise determination of the optimal time point for the termination of the colorimetric reaction. In this study, we introduce real-time signal analysis to quantify proteins by observing the continuous colorimetric signal change within the encoded hydrogel microparticles. Real-time signal analysis measures the "slope", the rate of the colorimetric signal generation, by focusing on the kinetics of the accumulation of colorimetric products instead of the colorimetric signal that appears at the end point. By developing a deep learning-based automatic analysis program that automatically reads the code of the graphically encoded hydrogel microparticles and obtains the slope by continuously tracking the colorimetric signal, we achieved high accuracy and high throughput analysis. This technology has secured a dynamic range more than twice as wide as that of the conventional end-point signal analysis, simultaneously achieving a sensitivity that is 4-10 times higher. Finally, as a demonstration of application, we performed multiplex colorimetric immunoassays using real-time signal analysis covering a wide concentration range of protein targets associated with pre-eclampsia.

Wearable, disposable and non-enzymatic fluorescence nanosensor for monitoring sweat glucose through smartphone

The promise of non-invasive health monitoring has fuelled the development of wearable biosensors for in situ detection of biological analytes in sweat. This paper presents a new fluorescent nanosensor probe based on boric acid functionalized and heteroatom doped carbon quantum dots (CQDs) embedded in paper-based analytical devices and integrated with a hydrophilic cotton thread-based microfluidic channel for the development of a flexible, wearable, biocompatible, and biodegradable sweat sensor for real-time measurement of sweat glucose concentration via smartphone readout. The morphological, physiochemical, compositional, crystallinity, and optical properties of nanosensors were extensively investigated. CQD particle sizes were found to be widely dispersed, ranging from 2.6 to 7.1 nm, with an average diameter of 4.38 nm. A dual response via fluorescence and colorimetric change was demonstrated for on-site sweat glucose monitoring using a smartphone camera to capture images in RGB (red, green, and blue) format and analyse them simultaneously by a customized android app, with quantitative results displayed on the smartphone. The limit of detection value for in situ measurement of sweat glucose concentration was 1.40 to 2.00 μM (25.25 to 36.13 μg/dL) and the limit of quantification value was 4.67 to 6.69 μM (84.16–120.44 μg/dL) in the pH range of 4.5 to 7.5. The developed sensor's performance metrics were validated using a standard clinical technique, which indicates strong correlation between two methods with Pearson correlation coefficient values of 0.83 and 0.80 for non-diabetic and type- II diabetes patients, respectively. Besides, interference, spike, and recovery studies were carried out with recovery rates ranging from 96.5 to 105.8 %, demonstrating good repeatability and reproducibility. Furthermore, feasible fluorescence quenching processes have been explored. In addition, the disposable and biodegradable nature of the nanosensor probe was studied by throwing it into the soil in the natural environment, where it dissolves almost spontaneously after three weeks.

Semi-quantitative and visual detection of Cu2+ and glyphosate in real samples and living cells using fluorescent and colorimetric dual-signals peptide-based probe

The excessive emission of copper ions (Cu2+) and the abuse of glyphosate (Glyp) have caused serious harm to the ecological environment and human health, so it is important to develop a fast and convenient method for the analysis of Cu2+ and glyphosate to ensure environmental and food safety. Herein, a dual-signals peptide-based probe (FASRH) with fluorescent and colorimetric was prepared using 5-carboxyl fluorescein modified tetrapeptide (Ala-Ser-Arg-His-NH2). FASRH was successfully used to recognize Cu2+ as a fluorescence “on–off” probe, forming the FASRH-Cu2+ complex with non-fluorescence. As a new promising cascade probe, FASRH-Cu2+ complex probe has high selectivity (only Glyp), good sensitivity (50.2 nM), good anti-interference ability and wide pH range (7.0–11.0) for the detection of glyphosate by ligand replacement method. In addition, the recognizable color changed markedly under 365 nm UV light and natural light. Notably, FASRH not only achieved accurate monitoring of Cu2+ and glyphosate in two real water samples, but also successfully applied to detect Cu2+ and glyphosate in live Hacat cells based on low cytotoxicity. Moreover, it is worth noting that FASRH-impregnated test strips exhibited significant fluorescence and colorimetric color changes for Cu2+ and glyphosate via naked eye. Furthermore, smartphone-assisted FASRH was used for the portable detection of Cu2+ and glyphosate based on the advantages of simplicity, low cost and fast response.

Pressure-resistant and portable array gas membrane device for rapid Escherichia coli detection in infant milk powder via smartphone colorimetry with all-in-one preparation strategy

This study presents a novel Pressure-Resistant and Portable Array Gas Membrane Separation (PAGMS) device for the rapid, smartphone-based detection of Escherichia coli (E. coli) in infant milk powder. The PAGMS device efficiently separates acetic acid, a byproduct of E. coli growth, enhancing detection sensitivity. Utilizing bromocresol violet as an indicator, this method quantifies E. coli based on colorimetric changes, with UV spectrum absorbance shifts indicating a linear correlation (R2 = 0.9864) within 5.0–120 μmol/L acetic acid concentration. Visual MINTEQ simulations validate the mechanism behind the indicator’s response. The approach surpasses traditional plate culture methods in terms of sample preparation time, achieving detection within a comparable timeframe of 15 min, and can concurrently process up to 48 samples, thereby substantially enhancing analytical throughput while detecting E. coli with a limit of detection of 5 cfu/g. This method demonstrates enhanced sensitivity, speed, and high-throughput capabilities, offering significant advantages in food safety monitoring.

Cold and ultra-cold chain integrity monitoring via embedded resonant sensor indicators

An increasing number of products require transport at cold and ultra-cold temperatures, < 5 and −60°C respectively. Time-temperature indicators (TTIs) are used to monitor the integrity of the cold chain, however, they are frequently based on colorimetric changes that can be inaccurate for quantification and not possible to read through closed shipment materials. Here, TTIs were prototyped using microfluidic channels containing fluids (oils) that are tuned to melt above target temperatures. By coupling these TTIs to resonant sensors, the time-temperature information can be transmitted wirelessly and quantitatively by observing shifts in resonant frequency. Multiplexed TTIs containing fluids that melt at 9, 13.5, and 19.5°C are demonstrated. When coupled to the resonant sensor, the fluid flows as the temperature increases incrementally and generates a frequency shift of 3.5, 4.5, and 6 MHz at each threshold. TTI for ultra-cold environments were also designed using microfluidic channels with melt responsive fluids (ethanol). The resonant sensor coupled TTI was placed in a Styrofoam container containing dry ice, and over 1 MHz frequency shift is observed when read external to the container as the dry ice evaporates and the temperature exceeds −35°C. This augurs potential uses in inexpensive monitoring of food and pharmaceutical shipments that must remain cold for adequate quality.

A benzimidazole-appended double-armed salamo type fluorescence and colorimetric bifunctional sensor for identification of MnO4− and its applications in actual water samples

The symmetrically double-armed salamo type fluorescent sensor BMS, incorporating benzimidazole units, was designed and synthesized. Showcasing remarkable specificity and responsiveness to MnO4- within a DMSO:H2O (V/V = 9:1, pH = 7.2) Tris-HCl buffer medium, it enabled dual-channel detection of MnO4- through fluorescent and colorimetric changes. Critical experimental parameters, including detection and quantification thresholds (LOD and LOQ) along with binding affinity constants (Ka), were calculated using the Origin software. A rational interaction mechanism between BMS and MnO4- was deduced, based on fluorescence titration, Electrospray Ionization Mass Spectrometry (ESI-MS), Ultraviolet–Visible Spectroscopy (UV–Vis), Infrared Spectroscopy (IR), Stern-Volmer plots, and Density Functional Theory (DFT) computations. Additionally, the sensor BMS was applied to monitor MnO4- in real water samples. Advancing its practical utility, BMS was fabricated into test strips for the selective detecting of MnO4-.

A pyrene-based chromo-fluorogenic probe for specific detection of sarin gas mimic, diethylchlorophosphate.

Nerve agents are becoming serious issues for the healthy and sustainable environment of modern civilization. Therefore, its detection and degradation are of paramount importance to the scientific community. In the present contribution, we have introduced a chromo-fluorogenic pyrene-based probe, (E)-2-methoxy-3-(pyren-1-ylimino)-3,8a-dihydro-2H-chromen-4-ol (PMCO)to detect sarin stimulant diethylchlorophosphate (DCP) in solution and gaseous phases. On inserting DCP in PMCO solution, a visual colorimetric change from yellow to clear colourless in daylight and highly intensified blue fluorescence was observed instantly under a 365 nm portable UV lamp light. PMCO has outstanding selectivity and high sensitivity with a limit of detection of 1.32 μM in dimethyl sulfoxide (DMSO) medium and 77.5nM in 20% H2O-DMSO. A handy strained paper strip-based experiment was demonstrated to recognize DCP in a mixture of similar toxic analytes. A dip-stick experiment was performed to identify DCP vapour, and may be used as an effective photonic tool. We also demonstrated real sample analysis utilizing different DCP-spiked water samples and validating DCP detection even in various types of soils such as sand, field, and mud. Therefore, this present study provides an effective chemosensor for instant and on-site detection of toxic nerve agents in dangerous circumstances.

Nanozyme sensor array based on Fe, Se co-doped carbon material for the discrimination of Sulfur-containing compounds

Developing methods for the accurate identification and analysis of sulfur-containing compounds (SCCs) is of great significance because of their essential roles in living organisms and the diagnosis of diseases. Herein, Se-doping improved oxidase-like activity of iron-based carbon material (Fe-Se/NC) was prepared and applied to construct a four-channel colorimetric sensor array for the detection and identification of SCCs (including biothiols and sulfur-containing metal salts). Fe-Se/NC can realize the chromogenic oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by activating O2 without relying on H2O2, which can be inhibited by different SCCs to diverse degrees to produce different colorimetric response changes as “fingerprints” on the sensor array. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed that nine kinds of SCCs could be well discriminated. The sensor array was also applied for the detection of SCCs with a linear range of 1–50 μM and a limit of detection of 0.07–0.2 μM. Moreover, colorimetric sensor array inspired by the different levels of SCCs in real samples were used to discriminate cancer cells and food samples, demonstrating its potential application in the field of disease diagnosis and food monitoring. Environmental ImplicationsIn this work, a four-channel colorimetric sensor array for accurate SCCs identification and detection was successfully constructed. The colorimetric sensor array inspired by the different levels of SCCs in real samples were also used to discriminate cancer cells and food samples. Therefore, this Fe-Se/NC based sensor array is expected to be applied in the field of environmental monitoring and environment related disease diagnosis.

Highly specific and sensitive chromo-fluorogenic detection of sarin, tabun, and mustard gas stimulants: a multianalyte recognition approach.

Nerve agents are the most notorious substances, which can be fatal to an individual because they block the activity of acetylcholinesterase. Fighting against unpredictable terrorist assaults and wars requires the simple and quick detection of chemical warfare agent vapor. In the present contribution, we have introduced a rhodamine-based chemosensor, BDHA, for the detection of nerve gas-mimicking agents diethylchlorophosphate (DCP) and diethylcyanophosphonate (DCNP) and mustard gas-mimicking agent 2-chloroethyl ethyl sulfide (CEES), both in the liquid and vapor phase. Probe BDHA provides the ability for detection by the naked eye in terms of colorimetric and fluorometric changes. It has been revealed that the interaction between nerve agents mimics and probe BDHA facilitates spirolactam ring opening due to the phosphorylation process. Thus, the highly fluorescent and colored species developed while probe BDHA is colorless and non-fluorescent due to the intramolecular spirolactam ring. Moreover, probe BDHA can effectively recognize DCP, DCNP, and CEES in the µM range despite many toxic analytes and could be identified based on the response times and quantum yield values. Inexpensive, easily carried paper strips-based test kits were developed for the quick, on-location solid and vapor phase detection of these mustard gas imitating agents (CEES) and nerve gas mimicking agents (DCP and DCNP) without needing expensive equipment or skilled personnel. More remarkably, the test strips' color and fluorescence can be rapidly restored, exposing them to triethyl amine (TEA) for cyclic use, suggesting a potential application in the real-time identification of chemical warfare agents. To accomplish the on-location application of BDHA, we have experimented with soil samples to find traces of DCP. Therefore, the chromo-fluorogenic probe BDHA is a promising, instantaneous, and on-the-spot monitoring tool for the selective detection of DCP, DCNP, and CEES in the presence of others.

Highly selective dual-responsive chemosensor for S2- in pure water and its application to environmental samples such as beverage, zebrafish and food spoilage

A new dual-responsive chemosensor NOP (4-(7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)piperazin-1-yl)(pyrazin-2-yl)methanone) was synthesized. Chemosensor NOP selectively probed S2- via fluorescent turn-off and colorimetric change from yellow to pink in pure water. The detection limit of NOP for S2- was determined to be 1.22 μM (fluorescence) and 1.05 μM (colorimetry), which were much below the WHO standard (14.8 μM). The detection mechanism of S2- was illustrated to be thiolysis reaction of NBD-amine moiety by 1H NMR titrations, ESI-mass, and DFT calculations, producing the cleavage product (NBD-S-). NOP could successfully quantify S2- in water, beverage samples, and zebrafish. Practically, NOP-coated strips could be employed for easy and rapid recognition of S2- in real-field and for monitoring food spoilage by dual-response. Therefore, NOP assured an auspicious approach for reliable S2- detection in real-field and food systems.

Development of green and sustainable ammonia sensor from xanthohumol extract-immobilized polylactic acid nanofibers

Ammonia is a significant industrial gaseous agent that is colorless. However, long exposure to ammonia gas can cause organ damages or even death. This study describes the preparation of a solid-state vapochromic sensor for gaseous and aqueous ammonia using eco-friendly smart colorimetric polylactic acid nanofibers. Xanthohumol (XMOL) is a natural spectroscopic probe that can be found in the common hop (Humulus lupulus L.) plant. Nanoparticles of mordant/xanthohumol (M/XMOL) coordinated complex were synthesized by immobilizing the xanthohumol direct dyestuff into polylactic acid nanofibers in the presence of a mordant (potassium aluminum sulfate). Xanthohumol can be described as an appropriate sensor for gaseous and aqueous ammonia due to its tiny molecular size and high water-solubility. Both of CIE Lab color parameters and absorbance spectra were used to inspect the color shift of the xanthohumol-finished polylactic acid nanofibers from yellow to colorless upon exposure to ammonia. This could be attributed to the intramolecular charge transfer caused by molecular switching of xanthohumol. In a fraction of second, the polylactic acid nanofibrous fabric showed a colorimetric change with a detection limit of 10–450 mg/L. The absorption spectra of the xanthohumol probe exhibited hypsochromic shift with a wavelength change from 465 nm to 315 nm (isosbestic point of 370 nm) in response to an aqueous solution of ammonia. Transmission electron microscopic (TEM) images showed that M/XMOL particles were 13–27 nm in diameter, whereas scanning electron microscopic (TEM) images demonstrated that the polylactic acid nanofibers were 150–450 nm in diameter. We observed no significant differences in air-permeability and bending-length of the nanofibrous fabric after immobilization of M/XMOL into polylactic acid nanofibers. In addition, the colorfastness properties of the treated polylactic acid nanofibers were investigated.

Selective Partitioned Regression for Accurate Kidney Health Monitoring

The number of people diagnosed with advanced stages of kidney disease have been rising every year. Early detection and constant monitoring are the only minimally invasive means to prevent severe kidney damage or kidney failure. We propose a cost-effective machine learning-based testing system that can facilitate inexpensive yet accurate kidney health checks. Our proposed framework, which was developed into an iPhone application, uses a camera-based bio-sensor and state-of-the-art classical machine learning and deep learning techniques for predicting the concentration of creatinine in the sample, based on colorimetric change in the test strip. The predicted creatinine concentration is then used to classify the severity of the kidney disease as healthy, intermediate, or critical. In this article, we focus on the effectiveness of machine learning models to translate the colorimetric reaction to kidney health prediction. In this setting, we thoroughly evaluated the effectiveness of our novel proposed models against state-of-the-art classical machine learning and deep learning approaches. Additionally, we executed a number of ablation studies to measure the performance of our model when trained using different meta-parameter choices. Our evaluation results indicate that our selective partitioned regression (SPR) model, using histogram of colors-based features and a histogram gradient boosted trees underlying estimator, exhibits much better overall prediction performance compared to state-of-the-art methods. Our initial study indicates that SPR can be an effective tool for detecting the severity of kidney disease using inexpensive lateral flow assay test strips and a smart phone-based application. Additional work is needed to verify the performance of the model in various settings.

Quinoline-based hydrazones for biocide detection: Machine learning-aided design of new TBT chemosensors

Antifouling compounds are used as paint components to mitigate biofouling on ships and submerged structures. One of the most known and used antifouling compounds is tributyltin (TBT). However, TBT is toxic to aquatic living beings, causing problems such as reduction of growth and imposex. The development of a TBT chemosensor could be of utter relevance in the building of an in-situ TBT monitoring device. Therefore, this work reports the synthesis of five new quinoline-based hydrazones (HZ) and two new quinoline-based thiosemicarbazones (TSC), with synthesis yields from 17 to 83 %. The compounds were tested in the presence of TBT, and some compounds of the group showed colorimetric or fluorimetric changes. The interaction between these compounds and TBT was tested by spectrophotometric or spectrofluorimetric titrations, which allowed to calculate the limit of detection (LOD) for each interaction. The fluorimetric interaction between HZ 4a and TBT was shown to be the most sensitive chemosensory method, with a LOD value of 1.7 μM.A Ridge classifier model was developed to correlate the ability for TBT detection and the modification of the structure of each molecule. The validity of the proposed model was tested by assessing the TBT-sensing ability of the two novel TSC 5a and 5b, which were synthesized after the development of the model. These two compounds also showed colorimetric changes in the presence of TBT, with LODs of 13.8 and 3.1 μM, respectively, in good accordance with the model's predictions. Further analysis of the model's decision process provided some insights on the desirable properties of the novel quinoline-derived TBT optical chemosensors.

A novel fluorescent and colorimetric dual-signals peptide-based probe for sequential recognition of Cu(II) and cimetidine and its multi-functional applications

A novel dual-signals peptide-based probe FDKSH was designed and synthesized based on 5-carboxy fluorescein (5-FAM) labelled tetrapeptide backbone (Asp-Lys-Ser-His-NH2). FDKSH exhibited a highly selective fluorescence “on-off” response and obvious colorimetric recognition to Cu2+ in 10 mM HEPES buffer solution at pH 7.4. Meanwhile, the limit of detection (LOD) was found to be 62.1 nM, which was much lower than that of stated by World Health Organization (WHO) in drinking water (30.0 μM). As a new promising cascade probe, the Cu(II)-assisted peptide ensemble probe (FDKSH-Cu2+ ensemble) has very high selectivity for cimetidine by the displacement method with LOD of 63.5 nM. In addition, FDKSH was successfully used to determine Cu2+ and cimetidine in two actual water samples. Additionally, FDKSH was also successfully used for monitoring Cu2+ and cimetidine in living cells and zebrafish, and showed low toxicity and excellent fluorescence imaging performance. It is worth noting that FDKSH-impregnated test strips exhibited significant fluorescence and colorimetric color changes for Cu2+ and cimetidine directly observed by naked eye. What’s more, smartphone with RGB color recognition function provided a new method for semi-quantitative visual detection of Cu2+ and cimetidine by analyzing different concentrations of Cu2+ and cimetidine without expensive instruments.

3D/4D printed versatile fibre‐based wearables for embroidery, AIE‐chemosensing, and unidirectional draining

AbstractFibre‐based wearables for embroidery, chemosensing, and biofluid's unidirectional draining with good flexibility, tunability, and designability drive technological advance. However, synthetic polymer fibres are non‐degradable, threatening the environment and human health. Herein, we have developed versatile microfibre‐based wearables by combining many advantages in one platform of biodegradable polylactic acid (PLA) and melt electrowriting strategy. Diverse potential applications of PLA wearables are achieved by flexibly designing their printing files, components and structures. Three‐dimensional printing files are generated from two‐dimensional images to fabricate ‘embroidery‐like’ patterns. PLA/aggregation‐induced emission fluorogens (AIE) chemosensors exhibit colorimetric and fluorescent colour changes upon exposure to amine vapours. Janus PLA‐cotton textiles with a hydrophobic/hydrophilic structure could facilitate unidirectional draining of sweats which is favourable for the management of temperature and humidity on the surface of skin. The proposed platform can not only broaden the design possibilities in 3D/4D printing but also offer wide potential applications for functional wearables.

A Julolidine Coupled Azine-based Reversible Chromo-fluorogenic Probe for Specific Detection of Cu2+Ions.

Among the various essential trace elements for living organisms, the copper (Cu2+) ions are the most important. However, Cu2+ ions are vital for the human body and are associated with necessary physiological processes; insufficient or excessiveness has many hazardous effects on our bodies. In the present contribution, strategically, we have introduced a julolidine-coupled azine-based, 9,9'-((1E,1'E)-hydrazine-1,2-diylidene bis(methanylylidene)) bis(1,2,3,5,6,7-hexahydropyrido [3,2,1-ij] quinolin-8-ol) (HDBQ) reversible chromo-fluorogenic probe for specific detection of Cu2+ ions. Probe HDBQ exhibits observable orange colorimetric change from yellow, which is visible to the naked eye in daylight. The highly green fluorescence HDBQ becomes a non-fluorescent one with the incorporation of Cu2+ ions. Interestingly, the colorimetric change and non-fluorescent HDBQ-Cu2+ complex reverse to the original HDBQ in the presence of ethylenediamine tetraacetic acid (EDTA). The detection and quantification limit of HDBQ towards the detection of Cu2+ ions is found to be in the µM range, which is much lower than the limit (31.5µM) recommended by WHO. We have also performed a colorimetric and fluorometric paper-based test strips-based experiment employing HDBQ for real-time on-site detection of Cu2+ ions. Using the reversibility characteristics of HDBQ for the consecutive addition of Cu2+ and EDTA, we have established the INHIBIT molecular logic gate. The present report brings a precise and sensitive probe for the detection of Cu2+ ions in real environmental and biological samples.

Uric acid quantification via colorimetric detection utilizing silver oxide-modified activated carbon nanoparticles functionalized with ionic liquid.

Uric acid (UA) is a significant indicator of human health because it is linked to several diseases, including renal failure, kidney stones, arthritis, and gout. Uric acid buildup in the joints is the source of chronic and painful diseases. When UA is present in large quantities, it causes tissue injury in the joints that are afflicted. In this research, silver oxide-doped activated carbon nanoparticles were synthesized and then functionalized with an ionic liquid. The synthesized nanomaterial assembly was employed as a colorimetric sensing platform for uric acid. Activated carbon offers a large internal surface area that acts as a good carrier for catalytic reactions. A salt-melting approach was used to synthesize the silver oxide-doped activated carbon nanocomposite. The synthesis was confirmed through various techniques, such as UV-vis spectrophotometer, FTIR, XRD, SEM, and EDX. The colorimetric change from blue-green to colorless was observed with the naked eye and confirmed by UV-vis spectroscopy. To obtain the best colorimetric change, several parameters, such as pH, capped NP loading, TMB concentration, hydrogen peroxide concentration, and time, were optimized. The optimized experimental conditions for the proposed sensor were pH 4 with 35 μL of NPs, a 40 mM TMB concentration, and a 4 minutes incubation time. The sensor linear range is 0.001-0.36 μM, with an R2 value of 0.999. The suggested sensor limits of detection and quantification are 0.207 and 0.69 nM, respectively. Potential interferers, such as ethanol, methanol, urea, Ca2+, K+, and dopamine, did not affect the detection of uric acid.

A bioactive multifunctional dressing with simultaneous visible monitoring of pH values and H2O2 concentrations for promoting diabetic wound healing.

Wound healing in diabetes is a complex physiological process with risks of ulceration and amputation. Real-time monitoring and treatment of diabetic wounds is an effective prevention of further deterioration. Herein, a multifunctional dressing is developed by encapsulating europium-containing bioactive glass (EuBG) and MoO3-x in a biocompatible sodium alginate (SA) dressing (MoO3-x-EuBG-SA), aiming to simultaneously monitor the wound pH value and hydrogen peroxide (H2O2) concentration, establish an anti-inflammatory microenvironment, and promote wound healing. The pH-responsive fluorescence quenching effect of EuBG contributes to visible monitoring of pH values, and MoO3-x enables high responsiveness and accurate colorimetric indication of H2O2 variability to understand the dynamic wound status. Then, these fluorescent and colorimetric changes can be captured using a smartphone and transformed into signals for wound pH values and H2O2 concentrations, enabling rapid and convenient real-time assessment of wound dynamics. Furthermore, the MoO3-x-EuBG-SA dressing can reduce inflammation and promote the proliferation, differentiation, and migration of fibroblasts and endothelial cells in vitro with the help of the released bioactive Si, Ca, and Mo ions. Notably, the MoO3-x-EuBG-SA dressing exhibits excellent abilities to monitor a wound microenvironment and immune regulation and promote diabetic wound healing in vivo. Overall, the multifunctional dressing has great potential for managing diabetic wounds and promoting wound healing.