The pursuit of next-generation supercapacitors with high energy density requires not only the design of robust electrode material, but also the engineering of the electrolyte. Herein, we explore a redox-mediated gel polymer electrolyte (GPE) using polyvinyl alcohol (PVA) and hydroquinone (HQ)/benzoquinone (BQ) couple to enhance the supercapacitive performance of mesoporous graphitic carbon nitride (mg-CN). The mg-CN nanosheet was synthesised via a carboxymethyl cellulose-assisted templating approach. The structural, spectroscopic and textural properties studies revealed the formation of mg-CN with abundant defect sites and sp2 carbon domains as well as a hierarchical porous structure with a surface area of 139 m2 g−1. Owing to the reversible redox reaction of the HQ/BQ couple leading to pseudocapacitance, mg-CN delivered a specific capacitance of 481 F g−1 at a scan rate of 5 mV s−1 in the 1 M H2SO4 + 0.01 HQ-based electrolyte, which is more than twice that of pristine H2SO4 (198 F g−1). Evidently, the capacitive-diffusive current contribution study indicated that 42.71% of the specific capacitance obtained in the HQ-based electrolyte is contributed by a diffusion-controlled process, as compared to the 19.81% obtained in the 1 M H2SO4 electrolyte. A symmetrical supercapacitor device fabricated using the redox-mediated GPE (1 M H2SO4 + PVA + 0.01 M HQ, PVA/HQ) exhibited a remarkable energy density of 47.42 Wh kg−1 at a power density of 6500 W kg−1, along with superior cycling stability. Owing to the improvement in the ionic conductivity of the gel offered by the charge carriers originating from the HQ (1 M H2SO4 + PVA: 371.44 vs. PVA/HQ: 401.81 mS cm−1), the device delivers an energy density of 47.42 Wh kg−1 when the power density is increased to 6500 W kg−1, an indication that the PVA/HQ electrolyte can be employed for the fabrication of a high-rate supercapacitor.

Dual targeting of human and bacterial hyaluronidases by skincare bioactives: Mechanistic basis and functional evidence.

A high-performance PdO@SWCNTs/NiO nanocomposite-based electrochemical sensor for sensitive and selective detection of hydroquinone.

Enhanced luminol chemiluminescence by MoO3/POM NRs for sensitive detection of hydroquinone.

ZIF-derived necklace-like N-doped porous carbon@MWCNTs loaded with Cu NPs for enhanced electrochemical sensing of dihydroxybenzene isomers.

Simultaneous and ultrasensitive detection of three dihydroxybenzene isomers based on 3D chain structure-modified MOF electrochemical sensors.

In this study, we investigated the effect of adding Artemisia absinthium L. flower extract on the properties of sesame oil. At first, A. absinthium essential oil was extracted and analyzed for free radical scavenging power (DPPH), total phenols, flavonoids, and the main constituent compounds by gas chromatography and high-performance liquid chromatography. Then, 5 sesame oil samples were prepared, namely a control sample (without A. absinthium e xtract), s amples w ith 0.5, 1, a nd 1.5% ethanolic extract of A. absinthium), as well as a sample containing tert-butyl hydro quinone. The samples were kept in an incubator at 40°C for 35 days. They were analyzed on days 0, 7, 14, 21, 28, and 35 for the values of peroxide, acid degree, thiobarbituric acid-reactive substances, p-anisidine, total oxidation, conjugated dienoic acid, and oxidative stability (Rancimat method). As the storage period progressed, physical and oxidative changes increased in all the samples. On day 35, the control sample demonstrated high peroxide value, acid degree value, thiobarbituric acid-reactive substances, p-anisidine value, total oxidation index, as well as conjugated dienoic acid. These results were significantly (p < 0 .05) h igher t han t hose i n t he s ample with 1.5% A. absinthium extract. The extract had nearly the same protective effects as synthetic antioxidant tert-butyl hydro quinone. Thus, A. absinthium extract at the concentration of 1.5% was more effective than the other samples in reducing the rate of lipid oxidation in sesame oil. A. absinthium extract demonstrated good potential as an effective natural antioxidant that is able to extend the shelf life of sesame oil.

Dual-signal ratiometric electrochemical aptasensor based on COFs-derived Fe/N-doped porous carbon and methylene blue-enriched COFs for sensitive and accurate detection of kanamycin.

Conducting polymers, as a type of pseudocapacitive material, have garnered significant attention in the development of all-organic supercapacitors due to their superior electrochemical properties. While extensive research has been conducted on p-type conducting polymers, n-type analogues continue to face challenges such as poor stability and narrow electrochemical windows. This study presents a method to enhance n-type conducting polymer poly(benzodifurandione) (PBFDO)-based supercapacitors by introducing hydroquinone (HQ) as a redox-active electrolyte additive. With 20 mM HQ, an increase in specific capacitance from 33 to approximately 60 F g-1 is observed, and the device retains over 93% capacity after 50,000 cycles. Experimental results demonstrate that HQ facilitates reversible doping/dedoping processes, thereby improving ion diffusion and polymer stability. Remarkably, even under an ultrahigh power density of 50,000 W kg-1, the device still delivers 5.6 Wh kg-1 of energy density, demonstrating exceptional high-power endurance. Similarly, other hydroquinone derivatives also improve rate capability and long-term stability, thereby mechanistically confirming the universality of this strategy for improving the performance of all-organic energy storage devices.

Convenient and sensitive detection of hydroquinone (HQ) and catechol (CC) in environmental samples holds great importance for monitoring. Herein, a vertically-ordered mesoporous silica film (VMSF) supported on the electrochemically pretreated glassy carbon electrode (p-GCE) is prepared by a simple and environmentally friendly electrochemical method and employed to construct a sensitive and anti-fouling sensing interface for quantitative detection of HQ and CC. In virtue of a simple electrochemical polarization, the p-GCE shows enhanced electroactive area and promoted electrochemical activity, as well as oxygen-containing groups, rendering a sensitive electrode substrate with improved analytical performance and the functional interface for stable growth of VMSF. The obtained VMSF/p-GCE has superior electroanalytical capacity toward HQ and CC due to the synergistic effect of hydrogen bonding of VMSF and the sensitive p-GCE electrode substrate. The developed VMSF/p-GCE sensor enables the determination of HQ and CC with a wide linear range (1 ∼ 120 μM), high sensitivity (0.368 μA/μM for HQ and 0.404 μA/μM) and low limit of detection (268 nM for HQ and 80 nM for CC). Furthermore, the capacity of the prepared VMSF/p-GCE in the analysis of HQ and CC in environmental water samples and soil leaching solutions has been studied, showing acceptable results and therefore offering a simple and low-cost way for environmental analysis.

Melasma is a common hyperpigmentary skin disorder. Because of its high prevalence and serious complications, including negative psychiatric effects, early diagnosis and treatment would be essential. This randomized, double-blind, case-controlled clinical trial compared the efficacy of niosomal tranexamic acid (TXA) 2%/niacinamide (NCA) 2% cream and conventional TXA 5%/NCA 4% cream with topical hydroquinone (HQ) 4% cream as a gold standard in melasma patients. A total of 99 patients were randomly assigned to three groups: Group A received niosomal TXA/NCA cream, Group B received conventional TXA/NCA cream, and Group C received HQ cream for three months. Each patient attended five dermatologist visits to evaluate clinical efficacy. All treatment groups showed a considerable reduction in melanin index and modified melasma area and severity index (mMASI) scores, as well as a notable improvement in patients’ quality of life. Although both niosomal TXA/NCA cream and conventional TXA/NCA cream were as effective as HQ cream in management of melasma, adverse reactions and relapse were observed in HQ group. Niosomal or conventional TXA/NCA creams are as effective as HQ 4% cream and due to less serious adverse reactions they would be better choices than HQ-containing preparations in hyperpigmentary disorders. Clinical Trial Registration No.: IRCT20220609055116N1 (Approval date: 07/23/2023).Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-26693-8.

Abstract Inorganic‐containing hybrid photoresists are critical for next‐generation extreme ultraviolet (EUV) lithography and angstrom‐era semiconductor miniaturization. However, associated conventional solution processing struggles to achieve ultrathin, uniform films with high conformality and compositional control, limiting overall patterning performance. Here, this study reports the systematic lithographic patterning characterization of an Al‐based hybrid resist synthesized via vapor‐phase molecular layer deposition (MLD), using the trimethylaluminum (TMA) metal precursor and the hydroquinone (HQ) aromatic organic linker. The resist supports both sub‐20 nm high‐resolution nanolithography and virtually infinite silicon plasma etch selectivity. Lithographic performance studied using electron beam lithography (EBL) as a proxy for EUV shows that, under an optimized process adopting post‐exposure bake, the resist achieves the best resolution of 15.4 nm linewidth under stringent 1:1 line‐space high‐density patterning—limited only by the minimum beam size of the EBL system. The resist also shows wide dose latitude and balanced performance in resolution, roughness, and sensitivity. The infinite silicon etch selectivity, stemming from spontaneous aluminum oxyfluoride passivation layer formation, enables fabrication of micrometer‐tall, 40 nm‐wide silicon nanofin structures using only a ≈30 nm‐thick resist layer, without no hard mask. These results highlight the potential of MLD‐based hybrid resists for developing next‐generation resist materials for micro/nanoelectronics manufacturing.

Rapid and selective electrochemical sensors for simultaneous detection of emerging environmental phenolic contaminants catechol (CC) and hydroquinone (HQ) in water was developed in this work. The sensor was fabricated through the modification glassy carbon electrode (GCE) with silver-nickel nanoparticles (Ag-NiNP/GCE) and molecularly imprinted poly(p-phenylenediamine) (MIP-p-PD-Ag-Ni/GCE) in the presence of CC and HQ as templates using electrodeposition technique sequentially. The elution of CC and HQ generated the specific binding sites to recognize and detect the templates with strong affinity. The electrodes and the materials were characterized using cyclic voltammetry, square wave voltammetry (SWV), Fourier infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. Experimental conditions such as number electropolymerization cycles, ratio of template-to-functional monomer, pH of electrolytes, and time of templates elution were carefully optimized. The SWV measurements showed that the sensor can detect the mixture of CC and HQ in phosphate buffer solution (pH 7) in the linear range of 0.75 -200 µM and 0-200 µM, with limit of detection (LOD) of 0.054 and 0.045 µM, respectively. The incorporation of Ag-NiNP in to MIPs improved the electrocatalysis of the targets through increasing the surface-area-to-volume ratio and conductivity of the electrode while the MIP played the role of selective recognition of CC and HQ analytes. The MIP-p-PD-Ag-NiNP/GCE sensor exhibited an acceptable percentage recovery of 96.45-102.56% with RSD of 2.62-3.54% for the water samples spiked with known quantities of CC and HQ. Furthermore, the proposed sensor revealed its high stability, selectivity and reusability which evidence its future applications in environmental monitoring applications.

Hydroquinone (HQ) is a redox-active organic compound widely used in cosmetics, pharmaceuticals, photography, and dye manufacturing. Despite its industrial utility, hydroquinone is considered toxic and potentially carcinogenic, necessitating the development of sensitive, rapid, and selective methods for its detection in environmental and biological samples. Traditional analytical techniques such as high-performance liquid chromatography, spectrophotometry, and fluorimetry, while effective, often suffer from drawbacks, including expensive instrumentation, time-consuming procedures, and complex sample preparation. In contrast, electrochemical biosensing offers a promising alternative due to its simplicity, portability, high sensitivity, and suitability for real-time monitoring.In the present work, we report the design and fabrication of a highly sensitive electrochemical biosensor based on a novel nanocomposite comprising Flavin Adenine Dinucleotide (FAD) functionalized fluorapatite (FA) and single-walled carbon nanotubes (SWCNTs). The FAD/FA/SWCNT composite was synthesized via a mechanochemical method, a green and scalable approach that eliminates the need for complex chemical treatments or high-temperature processes. Dimethyl sulfoxide (DMSO) was used as a dispersing solvent to ensure the homogeneous distribution of FAD molecules and nanotubes within the FA matrix. The synthesized composite was drop-cast onto a glassy carbon electrode (GCE) to construct the biosensor platform.The structural and physicochemical properties of the FAD/FA/SWCNT nanocomposite were characterized using a combination of high-resolution scanning electron microscopy (HR-SEM), X-ray diffraction (XRD), and UV–Visible spectroscopy. SEM analysis revealed a uniform, sheet-like morphology with well-dispersed nanotubes, providing a high surface area conducive to electrochemical reactions. XRD confirmed the crystalline structure of fluorapatite and the successful incorporation of SWCNTs, while UV–vis spectroscopy identified the characteristic absorption peak of FAD at 450 nm, indicating successful functionalization.The electrochemical properties of the modified electrode were evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and amperometry in 0.1 M phosphate buffer solution (PBS) at pH 7.4. The FAD/FA/SWCNT-modified GCE displayed a distinct redox peak at –0.45 V, attributed to the electroactive nature of FAD. The composite exhibited a significantly lower charge transfer resistance (Rct) compared to the bare and partially modified electrodes, highlighting the synergistic enhancement of electron transfer due to the integrated functionalities of FAD, FA, and SWCNTs.The electrocatalytic activity of the biosensor was systematically investigated for hydroquinone detection. The sensor showed a linear detection range from 0.005 µM to 258.2 µM, with a limit of detection (LOD) of 2.70 nM. This remarkable sensitivity is primarily attributed to the combined effects of: FAD serves as a redox-active mediator facilitating electron transfer, FA contributes to high surface area and biocompatibility, SWCNTs, which provide excellent electrical conductivity and enhance charge mobility. Scan rate studies indicated that the electrochemical response involves a mixed control mechanism, with contributions from both diffusion and surface-confined processes. The calculated charge transfer coefficient (α = 0.53) and linear dependence of peak current on both the square root and logarithm of scan rate further confirmed favorable reaction kinetics. The biosensor exhibited excellent reproducibility and operational stability, with consistent responses over 20 continuous cycles and minimal signal degradation.To validate the sensor’s real-world applicability, HQ detection was performed in spiked water samples (tap and mineral water) using the standard addition method. The biosensor demonstrated excellent recovery rates ranging from 100.4% to 103.0%, affirming its accuracy and reliability in complex sample matrices. Additionally, the sensor displayed a fast amperometric response time of approximately 4 seconds under optimized conditions at an applied potential of 0.09 V.When compared to existing HQ sensors based on advanced nanomaterials such as MoS₂/RGO, COF/CPE, and MWCNT-COOH/CTF-1, the FAD/FA/SWCNT-modified GCE outperformed in both detection range and sensitivity, demonstrating the strong potential of this composite for next-generation electrochemical biosensors.Importantly, this work marks the first report on the use of fluorapatite functionalized with a redox cofactor (FAD) for biosensing applications. The mechanochemical synthesis approach not only offers a sustainable and straightforward fabrication method but also enhances the composite’s performance due to the uniform dispersion and intimate interaction of all components. Conclusion: The FAD/FA/SWCNT-based electrochemical biosensor developed in this study offers a novel, efficient, and highly sensitive platform for hydroquinone detection. Its excellent analytical performance, combined with ease of fabrication and low detection limit, makes it a promising candidate for environmental monitoring and point-of-care diagnostics. This research also opens new avenues for incorporating bio-functionalized bioceramics into sensor technology, bridging the gap between nanomaterials, green chemistry, and practical biosensing applications. Figure 1

Recent work studying the interphase formation mechanism in solid state lithium ion batteries identified that barrier coatings which block oxygen migration should help stabilize interfaces between oxide cathode materials and thiophosphate solid electrolytes. Polyhydroquinone (pHQ) is attractive as a cathode coating for this application as pHQ conducts both lithium ions and electrons but restricts anion migration. In previous work, we reported a hybrid molecular layer deposition (MLD)/oxidative molecular layer deposition (oMLD) process to synthesize thin films of pHQ using a four-step process consisting of sequential doses of trimethylaluminum (TMA), hydroquinone (HQ), molybdenum pentachloride (MoCl₅), and HQ at 150 oC and ~1 Torr. However, when attempting to apply this process to layered nickel manganese cobalt oxide (NMC) cathode particles to stabilize solid state battery interfaces, the MoCl₅ vapor was found to oxidize the underlying NMC, resulting in buildup of chloride salts at the NMC/coating interface and failing to enable functional solid state batteries. In this work, we study modifications to the hybrid MLD/oMLD pHQ process to prevent the oxidation of the NMC substrate. Using film degradation in air as a metric of the extent of polymerization in the film, we find that a sufficiently thick metal-organic layer formed with multiple cycles of TMA/HQ acts as a buffer layer to prevent MoCl5 from accessing the underlying substrate, while still allowing for the formation of a conjugated polymer network of HQ monomers. Transmission electron microscopy (TEM) with energy dispersive X-ray spectroscopy (EDS) mapping confirms that this approach prevents MoCl5 from oxidizing NMC during pHQ growth. We also examine the effectiveness of these coatings as interfacial layers in solid state batteries. More broadly, this work presents a strategy for oMLD onto substrates that are susceptible to oxidation by the oxidants used in oMLD.

A new strategy was explored to crosslink the epoxidized natural rubber (ENR) using aminopropyl-terminated polydimethylsiloxane (AP-PDMS), enabling soft, transparent, and stretchable hybrid elastomers. The curing, catalyzed by hydroquinone (HQ) as a co-curing agent, proceeds via an amine-epoxy ring-opening reaction. The effects of HQ loading and curing time are systematically studied. The resulting nanocomposites showed exceptional flexibility (elongation at break ≈ 800%) and lower hardness than sulfur-cured ENR. The incorporation of flexible PDMS chains formed compliant hybrid networks with a glass transition temperature of ∼ -17.5°C, broadening their operational range.AP-PDMS further enhanced the homogeneous dispersion of silica nanoparticles, likely through interfacial interactions between its aminopropyl groups and silica surfaces, creating a well-integrated nanocomposite. High optical transparency arose from refractive index compatibility and uniform phase dispersion, while PDMS segments imparted enhanced hydrophobicity. Nanoindentation confirmed reduced modulus and hardness, underscoring microscale softness. 3D response surface plots mapped the mechanical behavior as a function of HQ content and curing time. This new class of hybrid ENR elastomers combines stretchability, softness, transparency, and hydrophobicity, making them promising candidates for applications where elasticity, transparency, and surface properties are of critical importance, offering a low-toxicity, scalable alternative to conventional crosslinking technologies.

Thenanozyme Cu5-ClNA with laccase-like activity was preparedby coordinating 5-chloronicotinic acid (5-ClNA) as a ligand with Cu2+. Further modification of Cu5-ClNA using 2,3,5,6-tetrafluorophenylthiophenol (TFTP) yielded the fluorescent nanozyme Cu5-ClNA-TFTP with enhanced laccase-like activity simultaneously. The resulting Cu5-ClNA-TFTP exhibited superior laccase-like activity with a higher maximal velocity (Vm = 3.504µM/min) and a lower Michaelis constant (Km = 0.177µM). In addition, the fluorescent nanozyme Cu5-ClNA-TFTP showed differential sensing of three dihydroxybenzene isomers and selective detection of catechol (CC) and hydroquinone (HQ). The selective detection of CC and HQ respectively was realized without the interference of resorcinol (RC). CC was detected with a lowlimit of detection (LOD = 0.016µg/mL) due to the fluorescence burst of Cu5-ClNA-TFTP that can be quenched by quinones. Detection of HQ was performed by a distinct shift in fluorescence color from red to green with an LOD of 0.028µg/mL. The method also achieved good detection results in real environmental water bodies and provided a new method for selective detection of CC and HQ.

The metabolism of hydroquinone (HQ) by tyrosinase presents significant biochemical and dermatological challenges, particularly due to its association with adverse effects such as exogenous ochronosis (EO). Despite its widespread use in skin-lightening products, the detailed mechanistic pathways of HQ metabolism by tyrosinase remain inadequately understood. This study aims to elucidate the mechanistic insights into the tyrosinase-catalyzed metabolism of HQ, leading to the production of HQ-eumelanin (HQ-EM) and HQ-pheomelanin (HQ-PM). We employed HPLC analysis to detect key intermediates and final metabolites. Results show that mushroom tyrosinase catalyzes the hydroxylation of HQ to 2-hydroxyhydroquinone (HHQ) via the 2-hydroxybenzoquinone (HBQ) pathway, giving rise to HQ-EM. However, in the presence of cysteine, a shift from HBQ to the benzoquinone (BQ) pathway occurs, giving rise to HQ-PM. Hydroiodic acid hydrolysis of HQ-PM and subsequent HPLC-electrochemical analysis identified 4-aminophenol (AP) as degradation product, thereby serving as a novel marker to monitor HQ oxidation in vitro. These results indicate that HQ functions both as a “pseudo” substrate for tyrosinase—undergoing redox exchange with dopaquinone to form BQ—and as a true substrate, yielding HBQ. This dual role contributes to the formation of HQ-EM and HQ-PM. It would be possible that EO is caused by a continuous oxidation of HQ mediated by tyrosinase activity in the skin.

A disposable dual-mode electrochemical/colorimetric paper-based analytical device for simultaneous detection of hydroquinone and mercury ion.

Abstract The pursuit of advanced energy storage systems requires the development of novel electrode materials and electrolyte formulations. In this work, we report a synergistic strategy that integrates mesoporous carbon electrodes with a dual redox‐active electrolyte consisting of 0.05 M NH 4 VO 3 and hydroquinone (HQ) in 1 M Na 2 SO 4 aqueous solution. The mesoporous carbon, with a high surface area of 1300 m 2 g −1 and interconnected pore structure, facilitated efficient ion diffusion and charge storage. The introduction of dual redox species markedly boosted faradaic contributions, accounting for 60% of the total capacitance, as verified by Trasatti analysis. This hybrid system delivered a remarkable specific capacitance of 1380 F g −1 at 1 A g −1 . In a symmetric two‐electrode configuration, a maximum specific energy of 116.2 Wh kg −1 and a specific power of 852 W kg −1 were achieved—representing more than a 14‐fold improvement over pure electrolyte system. Moreover, 90% capacitance retention after 4000 cycles at 4 A g −1 confirmed the long‐term durability of the device. These findings demonstrate a powerful approach to overcoming the energy–power trade‐off in supercapacitors, highlighting the practical potential of mesoporous carbon combined with dual redox‐active electrolytes for next‐generation energy storage technologies.