Photochemical Research Articles

Photochemistry dominates over photothermal effects in the laser-induced reduction of graphene oxide by visible light

Graphene oxide (GO) possesses specific properties that are revolutionizing materials science, with applications extending from flexible electronics to advanced nanotechnology. A key method for harnessing GO’s potential is its laser-induced reduction, yet the exact mechanisms — photothermal versus photochemical effects — remain unclear. Herein, we discover the dominant role of photochemical reactions in the laser reduction of GO under visible light, challenging the prevailing assumption that photothermal effects are dominant. Employing a combination of Raman thermometry, X-ray photoelectron and photoluminescence spectroscopies, and electrical atomic force microscopy, we quantify the temperature and map the reduction process across micro and nano scales. Our findings demonstrate that the photochemical cleavage of oxygen-containing groups below a reduction threshold temperature is a decisive factor in GO reduction, leading to distinct characteristics that cannot be replicated by heating alone. This work clarifies the fundamental mechanisms of GO transformation under visible laser irradiation, highlighting the dominant role of photochemical processes. Distinguishing these subtleties enables the development of laser-reduced GO platforms for graphene-based applications compatible with industrial scales. We illustrate this potential by encoding information on GO surfaces as optical storage, allowing us to write binary sequences in long-term memory encoding invisible even through an optical microscope.

Effect of ZnO/EAF slag doping on removal of methyl red dye (MR) from industrial waste water

Zinc oxide doped with EAF slag (ZnO/ EAF slag) nanoparticles in different contents (10, 20) % of waste were synthesized in a controlled and reproducible way using spin-coater. The produced nanomaterial’s physicochemical and structural characteristics were ascertained by means of particle size distribution, TEM, SEM, UV-Vis spectroscopy, XRD, FTIR, and XRF. The role and effect of EAF slag with constant percent doping with ZnO on the ability to remove pollutants was determined by observing the methyl red (MR) elimination in an aqueous solution at λmax = 413 nm and MR dye removal concentration was evaluated from its optical density. Irradiation of the compounds in sunlight intensity 250 KW/nh.m2 and temperature 36 °c resulted in a larger degree of MR removal from the solution, resulting in ZnO/EAF slag samples exhibiting increased photo activity. As a conclusion ZnO nanoparticles saturated with 20% EAF slag as a waste material were the most efficient in removing methyl red (MR) achieving ~ 96% removal and a completely transparent solution after 2 h of testing.

Distribution characteristics and photochemical effects of isoprene in a coastal city of southeast China

As forest coverage and urban greening increase in China, the impact of biogenic volatile organic compounds (BVOCs) on urban atmospheric environment cannot be neglected. As one of the most abundant and reactive BVOCs globally, isoprene plays a crucial role in atmospheric radical chemistry. However, the reports on quantifying the impact of isoprene on atmospheric photochemistry remain scarce. This study selected Xiamen, a typical coastal city in Fujian Province, as the research area. By employing field observation and Photochemical Box Model (PBM), the study investigated the distribution characteristics, pollution mechanisms, and impact on O3 of the atmospheric photochemical active species isoprene in coastal urban area. The study found that the average concentration of isoprene in summer was 4.7 times higher than that in autumn. Isoprene degradation primarily occurred through oxidation by OH· radicals, reaching 88 % and 86 % in summer and autumn, respectively. Based on scenario simulations using the PBM model, it was observed that isoprene photochemistry led to increased daytime concentrations of ROx radicals (summer: 24 %, autumn: 23 %), peroxyacetyl nitrate (PAN, 49 %, 44 %), and formaldehyde (HCHO, 37 %, 38 %). Additionally, isoprene photochemistry enhanced reaction rates of HO₂· + NO (summer: 21 %, autumn: 16 %) and RO₂· + NO (50 %, 52 %), ultimately resulting in a 19 % and 15 % increase in net O3 production rates in summer and autumn, respectively. This study provides scientific evidence for exploring the photochemical mechanisms and pollution control strategies of O3 in coastal atmospheric environments.

Probing Host‐Guest Inclusion Complex of DHP with β‐CD in Augmenting Bioavailability to Boost Biochemical Applications Optimized by Physicochemical and Molecular Docking

AbstractThis research aims to develop the inclusion complex of 2, 4‐diamino‐6‐hydroxypyrimidine (DHP) with β‐cyclodextrin (β‐CD) using an inclusion process, and to investigate the effect of inclusion on the photo stability and bioactivity of DHP. The formation of DHP‐β‐CD inclusion complex has been examined by means of physicochemical as well as spectroscopic techniques (1H NMR, FT‐IR, PXRD and SEM) suggesting the successful inclusion of the DHP molecule into the β‐CD cavity. The 1 : 1 stoichiometry of the inclusion complex was validated through Job's plot. β‐CD displayed a fairly strong affinity (Ka =889.67 M−1) for DHP, indicating that the binding process is thermodynamically feasible. A molecular docking study speculated the most preferred orientation of DHP molecule within the binding pocket of β‐CD cavity. The photostability of DHP was found to improve on complexation with β‐CD. In vitro antibacterial activity test demonstrated that the DHP‐β‐CD inclusion complex displayed better activity than pure DHP. DHP‐β‐CD inclusion complex (IC50 =240.04 μM) also exhibited relatively significant in vitro cytotoxic activity than pure DHP towards the human kidney cancer cell line (ACHN). These results reveals that the inclusion of DHP using β‐CD could lead to stabilization of DHP and efficient display of its bioactivity.

The Biofilm Removal and Bactericidal Effect of an 810-nm High-Power Laser on an Orthodontic Bracket Surface: An In Vitro Study.

Objective: The present study aimed to analyze the biofilm removal and bactericidal effect of laser treatment alone and laser combined with ultrasonic scaling on orthodontic brackets. It also assessed whether the use of a laser can improve the efficiency of biofilm removal and bactericidal effect compared with traditional ultrasonic instrumentation. Background Data: Streptococcus mutans (S. mutans) can lead to white spots and dental caries. Orthodontic brackets make teeth cleaning more difficult, and biofilms or bacteria on the surface of brackets worsen the oral environment, which may cause some oral diseases. Laser can be used for biofilm removal and killing bacteria on the surface of an object through thermal, photochemical, and pressure effects, which is widely used in the treatment of oral diseases. Methods: A total of 600 mandibular incisor brackets were collected for this study. Among these, 320 unused brackets were used for the S. mutans crystal violet assay (n = 160) and for S. mutans live/dead bacterial staining (n = 160). Another 280 brackets, obtained from patients who had undergone therapy for over two years, were used for the mature multispecies biofilms removal assay (n = 120) and multispecies bacterial live/dead bacterial staining (n = 160). Ultrasonic scaling, laser, and laser combined with ultrasonic scaling were applied to the labial surface of brackets covered by S. mutans biofilm or mature multispecies biofilms. Specifically, we used the following three methods: ultrasonic scaling for 10 sec without laser; 810-nm laser (Doctor Smile, Italy, LA5D0 001.1) with 0.3-mm spot size at total 21.2 kJ/cm2 for 10 sec; and 810-nm laser at total 10.6 kJ/cm2 for 5 sec, followed by ultrasonic scaling for 5 sec. The 810-nm diode laser removed biofilms with a power of 1.5 W and a power density of 2.12 kW/cm2. The S. mutans biofilm was examined using crystal violet assay, and scanning electron microscopy (SEM) was used for mature multispecies biofilms to evaluate the effect of the three methods on biofilm removal. Live/dead bacterial staining was used to examine the bactericidal effect on remaining biofilms by confocal laser scanning microscopy (CLSM). Results: For S. mutans biofilm, the optical density (OD) value and live/dead bacterial ratio in the laser and the laser combined with ultrasonic scaling groups were significantly lower than those in the ultrasonic scaling group (p < 0.05); moreover, the OD value and the live/dead bacterial ratio in laser treatment combined with ultrasonic scaling and laser treatment alone showed no significant difference (p > 0.05). For mature multispecies biofilms, the percentage of biofilm coverage after treatment was higher in the laser group than in the ultrasonic scaling group (p < 0.05) and lower in the laser combined with ultrasonic scaling group than in the ultrasonic scaling group (p < 0.05), and live/dead bacterial staining showed that laser treatment alone killed the most bacteria, followed by laser treatment combined with ultrasonic scaling, while ultrasonic scaling alone seldom killed bacteria. Conclusions: Laser treatment alone has a better bactericidal effect and can also remove more S. mutans biofilm than ultrasonic scaling alone, but it fails to remove more mature multispecies biofilms. Laser treatment combined with ultrasonic scaling can remove more S. mutans biofilm and mature multispecies biofilms than ultrasonic scaling alone and also has a better bactericidal effect than ultrasonic scaling alone on a bracket surface.

Reconfigurable Visible Light-Driven Liquid Crystalline Network Showing Off-Equilibrium Motions Enabled by Mesogen-Grafted Donor-Acceptor Stenhouse Adducts.

Liquid crystalline network (LCN)-based soft actuators have opened up great opportunities to fabricate emerging and intriguing smart materials, serving as potential building blocks for intelligent soft robotics. Endowing LCN actuators with complex responsive behaviors to enhance their intelligence is both challenging and highly demanded. Herein, Donor-Acceptor Stenhouse Adducts (DASAs) molecules with rod-like mesogen and the polymerizable group are judiciously designed and synthesized, which is strong-colored at linear form and de-coloration at cyclic form after visible light. In the colored state, the DASA presents a striking photothermal effect that is capable of driving the motions of LCN film. Upon visible light irradiation, the DASA becomes colorless, making the diminishing photothermal effect. The light-gated switching of the photothermal effect renders the LCN films to be reconfigurable and perform off-equilibrium motions. The varying glass transition temperature of LCN matrix endowing tunable isomerization rates of DASAs and the equilibrium balance of photo- and thermal-isomerization at different temperatures in LCN-P-DASA film mainly guiding the off-equilibrium or stable motions, providing high adjustability of the novel visible light-driven LCN actuators. The multiply modulated LCN-P-DASA film holds great potential in constructing complex visible light-driven soft actuators based on the synergetic effect and interactions of photochemical and photothermal effects.

A novel merocyanine photoacid for visible light-controlled pH modulation

Merocyanine-based photoacids generate high proton concentrations under visible light irradiation. In the past decade, it has been established that these photoacids offer significant advantages over photoacid generators (PAGs) and hydroxyaryl photoacids, enabling better spatiotemporal control of proton transfer reactions in bulk media. In this study, we modified the core structure of the first generation of meroyanine photoacids. We developed a novel photoacid with color tuning capabilities and high solubility in polar organic solvents. Specifically, by incorporating a cationic benzoindolium moiety as an acceptor, we have altered the photoacid’s light absorption properties. Unlike the first generation of indolium-based merocyanine photoacids, this photoacid can now be activated with green light (λmax = 525 nm) as well as blue (λmax = 450 nm) and ultraviolet (λmax = 365 nm) lights. Furthermore, the novel photoacid exhibits high photo stability, photo-acidity (Π = 3.28 ± 0.08) and moderate reverse reaction rate (k = 1.08 × 10−3 ± 0.00017 s−1) in solution. We envision that with improved color tuning capabilities, this class of photoacids will be a more versatile tool for controlling proton-induced reactions in different systems, including biological reactions.

Photoelectrochemical response of tin iodide phosphide (SnIP) composites with MoSe2, MoS2, and h‐BN

For a future world fuelled by green energy it is invaluable to develop, test and maximise the catalytic efficiency of new effective water‐splitting materials. In this paper, we further explore the catalytic activity of double‐helical tin iodide phosphide (SnIP), as it features bandgaps in the ideal region for this process. We found that its photoelectrochemical response can be multiplied by forming composites of SnIP with selected 2D materials, focusing on hexagonal boron nitride and the transition metal dichalcogenides (TMDs) MoSe2 and MoS2. These nanocomposites were analysed with Powder‐X‐ray diffraction (P‐XRD), Raman, and UV/VIS bandgap determination. Their photo activity was assessed under simulated solar light through chrono amperometry and linear sweep voltammetry (CA, LSV). The high anisotropy of the involved materials enables efficient charge separation at the 1D/2D interfaces, increasing photoelectrochemical response four‐fold.

TiO2 modified NiFe-LDH as photoanode to achieve high efficiency photochemical water oxidation reaction

With the semiconductor modified oxygen evolution (OER) catalyst as the photoanode, the solar energy can be fully utilized, and the synergistic reaction makes the OER catalyst play a great role in the photochemical (PEC) water decomposition. Herein, we adopted a one-step hydrothermal method to introduce TiO2 to form heterojunction as photoanode in a well-known NiFe-LDH electrocatalyst, which contributes to carrier separation and transfer efficiency, thereby speeding up the water oxidation reaction kinetics. Benefiting from the TiO2/Ni4Fe6-LDH heterojunctions, the TiO2/ Ni4Fe6-LDH shows an overpotential of 371 mV @30 mA cm−2 and a Tafel slope of 131.36 mV/dec under illumination, which is better than Ni4Fe6-LDH and TiO2. The comparison experiment of oxygen evolution efficiency showed that the polarization current density of TiO2/Ni4Fe6-LDH reached 12 mA cm−2 under the illumination voltage of 1.72 V, which was twice the current density under the non-illumination condition. Surface electronic structure analysis shows that these excellent OER performance are largely due to the introduction of TiO2, which not only enables Ni4Fe6-LDH surface to have more oxygen vacancy, increase photoanode conductivity and accelerate reaction electron conduction, but also accelerates hole capture and enhances OER reaction kinetics. This synergistic effect between semiconductor and OER catalyst provides more ideas for realizing efficient and stable photoelectrochemical water oxidation.

Boron Nitride‐Supported Fluorescein Isothiocyanate for Improving Optical Performance and Stability

AbstractOrganic luminogens play an indispensable role in optoelectronic devices, yet there is a pressing need to address their aggregation‐caused quenching (ACQ) and stability. Here we designed and prepared multilayered boron nitride nanosheets/fluorescein isothiocyanate (MBNNSs/FITC) composite phosphors with tunable photoluminescence by controlling the FITC content and annealing temperature. The research results indicate that MBNNSs/FITC with low or high loading of FITC is not conducive to enhancing the emission intensity of FITC, which can be attributed to the fact that low loading leads to a decrease in the content of fluorescent groups, while high loading promotes intermolecular aggregation of FITC dyes. Interestingly, the emission intensity of FITC in MBNNSs/FITC‐6 composite phosphors can be further enhanced by annealing treatment (200 °C), which can be ascribed to the suppression of the ACQ and effective energy transfer from the MBNNSs to the FITC. Moreover, the resultant composite phosphor displays outstanding thermal stability, remarkable photo stability and exceptional water‐resistance. This work provides a new design space for the development of non‐rare‐earth fluorescent materials using organic fluorescent dyes.

Oxidation of Polycyclic Aromatic Hydrocarbons (PAHs) Triggered by a Photochemical Synergistic Effect between High- and Low-Molecular-Weight PAHs.

Photooxidation of polycyclic aromatic hydrocarbons (PAHs), which are widely observed in atmospheric particulate matter (PM), largely determines their atmospheric fate. In the environment, PAHs are highly complex in chemical composition, and a great variety of PAHs tend to co-occur. Despite extensive investigation on the photochemical behavior of individual PAH molecules, the photochemical interaction among these coexisting PAHs is still not well understood. Here, we show that during photooxidation, there is a strong photochemical synergistic effect among PAHs extracted from soot particles. We find that neither small PAHs with low molecular weights of 200-350 Da and 4-8 aromatic rings (named PAHsmall) nor large PAHs with high molecular weights of 350-600 Da and 8-14 aromatic rings (named PAHlarge) undergo photooxidation under red-light irradiation (λ = 648 nm), even though PAHlarge can absorb light with this wavelength. Interestingly, when PAHlarge is mixed with PAHsmall, substantial photooxidation is observed for both PAHlarge and PAHsmall. Comparisons of in situ infrared (IR), high-resolution mass spectrometry, and electron paramagnetic resonance analysis indicate that the presence of PAHsmall inhibits the light quenching effect arising from the π-π stacking of PAHlarge. This leads to the formation of singlet oxygen (1O2), which initiates the photooxidation. Our findings reveal a new mechanism for the photooxidation of PAHs and suggest that complex atmospheric PAHs exhibit distinct photoreactivity from simple systems.

Comparative analysis of winter composite-PM2.5 in Central Indo Gangetic Plain cities: Combined organic and inorganic source apportionment and characterization, with a focus on the photochemical age effect on secondary organic aerosol formation

To gain insights into air quality dynamics, a high-end instrument such as High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) alongside an Aethalometer was used to measure the Composite PM2.5 (C-PM2.5) in Lucknow and Kanpur during winter. It encompasses non-refractive PM2.5 (NR-PM2.5) and Black Carbon (BC) mass concentrations. Significant variation was noted in average C-PM2.5 concentrations at both sites, as 168.8 ± 61.3 μg m−3 in Lucknow and 90.7 ± 25.7 μg m−3 in Kanpur. Organics emerged as the predominant component, constituting ∼55%–65% of the C-PM2.5 mass, followed by inorganics (24% and 30%) and BC (20% and 8%). The present study employs Positive Matrix Factorization (PMF) on combined organic and inorganic source apportionment, resolving eight and seven source factors at Lucknow and Kanpur, respectively. Both sites exhibit significant contributions from solid-fuel combustion organic aerosol (SFC-OA), with ∼11% in Lucknow and 8% in Kanpur. However, SFC-OA mass concentration in Lucknow, at 24.67 μg m-³, is nearly double that in Kanpur (12.05 μg m-³). This was likely due to domestic coal burning in the nearby households, unregulated open burning, and burning of garbage on roadsides. The study shows that both sites were affected by oxidized biomass burning OA (O-BBOA) emissions, with increased concentration during the night due to dark oxidation by NO3 radicals. The diurnal variation of secondary organic aerosols (SOA), such as O-BBOA and semi-volatile oxygenated OA (SVOOA), shows increasing concentration during daytime hours. Therefore, the photochemical aging (ta) role in SOA formation was analyzed, and it was revealed that the formation might primarily be driven by photochemical oxidation. Additionally, two inorganic-rich factors, sulfate and nitrate-related OA (SO4-OA and NO3-OA) at both sites and additional ammonium chloride-related OA (NH4Cl-OA) resolved at Lucknow. Our study shows that NO3-OA and SO4-OA formation was dominated by aqueous phase processes due to high relative humidity and decline in concentration with increasing ta (ta > 30 h) during winter.

On-site monitoring of L-adrenaline neurotransmitter in biological samples by chitosan oligosaccharide derived carbon dots

Carbon quantum dots (CDs) are fascinating fluorescent nanomaterial for spectrofluorimetry sensor applications, owing to the fact of its strong chemical stability, high quantum yield and high photostability. At this instance, we have developed the fluorescent sensing technique to detect the L-adrenaline (L-Adr) by nitrogen-doped carbon quantum dots as a sensing probe. The nitrogen-doped carbon dots was synthesized using chitosan oligosaccharide by hydrothermal method. The synthesized chitosan oligosaccharide derived CDs (COL-CDs) exhibits blue fluorescence under UV light and the size of the carbon quantum dots is 3.39 ± 0.08 nm calculated from HR-TEM image. The hormone called L-Adr found in the human body is crucial for controlling visceral processes. Utilizing the process of photo-induced electron transfer (PET), the previously mentioned COL-CDs have applied to sense the L-Adr. The sensing mechanism have explained clearly using Rehm-Weller equation by calculating ΔG. Tap water, blood serum, urine and adrenaline drug samples employed as real sample for the sensing L-Adr. A reagent free paper-based kit established for the purpose of on-site monitoring L-Adr. The smartphone’s colour picker software used to measure the RGB intensity from the paper-based kit.

Air-stable and UV-NIR broadband photodetectors utilizing graphene and core/shell quantum dots hybrid heterostructure

Photodetectors based on PbSe quantum dots (QDs) are commonly used for light detection in the near-infrared (NIR) region. Nevertheless, the performance of photodetectors based on PbSe QDs is constrained by ineffective carrier transfer and poor photo and thermal stabilities. Herein, a promising strategy that harnesses PbSe/PbS core/shell QDs structures is developed and demonstrated to enhance the long-term stability of photodetectors, further combining with graphene to form hybrid heterojunctions that effectively promote carrier transfer. As a result, the devices exhibit a broad photoresponse to the incident light at range of 365–1250 nm, and also possess a high photosensitivity of 1.5 × 104 A/W and a high detectivity of 4.0 × 1013 Jones. Moreover, the lifetime of graphene-PbSe/PbS core/shell QDs hybrid photodetector was 9 times greater than that of uncoated QDs devices. The enormous boost might be attributed to the passivation and protection provided by the core–shell structure, and graphene’s efficient extraction of charge carriers.

PM2.5 episodes in northern Taiwan under southerly winds in late winter

When northern Taiwan is influenced locally, PM2.5 events occur in specific conditions. If it is also affected by long-range transport from mainland China in the northwest, the probability of these PM2.5 events increases. The current study applies WRF/CMAQ to study such case but focus on the local. From April 7 to 9, 2019, the Pacific high pressure extended westward, causing the prevailing weak southerly wind near Taiwan. The intensity of the Pacific high pressure weakened, and the wind speed near Taiwan also weakened. Therefore, the PM2.5 concentration in Taiwan increased. In northern Taiwan, the hourly PM2.5 concentration will inevitably increase to approximately 70 μg m−3. The ISAM of the CMAQ model demonstrates that local contributions to daily PM2.5 concentrations at the four representative monitoring stations in northern Taiwan are 3.5 to 16.2 μg m−3, greater than those from central, southern, and eastern Taiwan, from 1.8 to 6.7 μg m−3. We use the integrated process rate (IPR) and integrated reaction rate (IRR) of CMAQ to explore the formation mechanisms of PM2.5. The main causes of the increase in PM2.5 concentration are horizontal advection (HADV), aerosol processes (AERO), emissions (EMIS), and a small amount of cloud processes and aqueous chemistry (CLDS). The main source of NO3− is the reaction between OH and NO2 during the day and the reaction between N2O5 and water vapor at night. The gaseous HNO3 concentration reaches a peak near noon or soon after. The aerosol ANO3 concentration is high in the early morning. We also use the Sulfur Tracking Method (STM) of CMAQ to explore the sources of SO42−. Mainly it is from the local reaction of SO2 and H2O2. Finally, we apply AERO7 in CMAQ to explore the main sources of carbon components. The organic carbon (OC) concentration is much greater than the element carbon (EC) concentration, which indicates a strong local photochemical effect in northern Taiwan. OC mainly comes from low-volatility/semivolatile oxidized combustion OC, followed by low-volatility/semivolatile POA. Similar weather conditions occur in autumn, winter, and spring. When the weak southerly wind was around Taiwan, PM2.5 in northern Taiwan was noticed.

Pulsed light technology for fresh‐cut produce: A review on mechanism and inactivation kinetics of microbes and enzymes

AbstractConsumers are becoming more aware of the benefits of eating healthy foods like fresh‐cut produce without compromising the quality of sensory and nutritional aspects. Emerging non‐thermal technology like pulsed light (PL) is one of the most potential surface decontamination methods for fresh‐cut produce. Unlike conventional methods, PL does not cause unwanted changes in finished products like nutritional losses, color, textural changes, production of off‐flavors, etc. Its application is confined to not only surface disinfection but also enzyme inactivation. The death of microbes is due to PL's photochemical and photothermal effects. The photochemical effect is also responsible for enzyme inactivation, and Weibull or log‐linear models can explain their inactivation kinetics. Despite several advantages, PL has limitations of less effectiveness in eliminating microorganisms due to low penetration into the tissue of fresh‐cut produce, which can be overcome by applying different absorption‐enhancing agents to improve absorption capacity. Moreover, in‐package treatment can avoid the problem of recontamination of the treated products. This review provides an overview of the mechanisms and kinetics involved in the inactivation of microbes and enzymes in PL treatment. Additionally, this paper reviews the advantages and limitations of utilizing PL technology for shelf‐life enhancement of fresh‐cut produce and compiles the recent works done to enhance the efficacy of PL treatment. Furthermore, future scope and remedies to solve the existing problems of PL and for commercialization of this technique in the field of fresh produce are discussed.

Pioneering Laser Applications In Modern Strategies For Sterilizing Periodontal Tissues

The integration of laser technology into periodontal therapy represents a revolutionary leap forward in the management of periodontal diseases, as it provides a highly precise and minimally invasive alternative to traditional mechanical methods such as air turbines and ultrasonic scalers, which frequently cause significant patient discomfort. Lasers, with their advanced delivery systems—including articulated arms, hollow waveguides, and fiber optics—leverage mechanisms such as photo thermal and photomechanical ablation, as well as photochemical effects, aids in accomplishing improved bacterial reduction, tissue coagulation, and regeneration. These innovations extend to a wide array of clinical applications, from soft tissue procedures like gingivectomy and laser-assisted new attachment procedures to hard tissue treatments and implant maintenance. Recent breakthroughs, including femto second and pico second pulsed lasers, continuous-wave lasers, and laser-induced plasma; have markedly enhanced precision and efficacy in periodontal care. Innovations in photo activated antimicrobial agents and laser-assisted microbial detection further optimize sterilization and treatment outcomes. This review accentuates the transformative impact of these cutting edge technologies, demonstrating their ability to enhance patient outcomes, reduce postoperative discomfort, and hasten up recovery. However, despite these promising advancements, continued research is crucial to establish lasers as a standard component of periodontal care. Hence, this ongoing exploration will pave the way for laser technology's further progression and incorporation into contemporary periodontal treatment strategies,ultimately redefining the parameters of care and establishing new benchmarks for patient comfort and clinical efficacy

HPTLC – densitometric method of analysis for estimation of efonidipine hydrochloride and telmisartan used in treatment of hypertension

Precise, accurate, and sensitive high performance thin layer chromatographic method has been developed and validated for simultaneous determination of efonidipine hydrochloride (EFD) and telmisartan (TEL) in a tablet dosage form which is used in treatment of hypertension. The proposed method used aluminum plates pre-coated with silica gel 60 F254 as a stationary phase and n-butanol: toluene: acetic acid (3:7:0.2, v/v/v) as a mobile phase for separation purpose. Compact spots of TEL and EFD were obtained at Rf 0.73 and 0.37, respectively. Densitometric detection was carried out at 299 nm in UV. Linear responses were shown by the detector over the range of 200–1200 ng/band for both drugs. The proposed method was validated as per ICH guidelines. The method was successfully applied for estimation of both drugs in tablet formulations. Forced degradation study was carried and efonidipine was found to be susceptible to base hydrolysis and oxidative stress degradation while TEL was stable in acid-base hydrolysis, oxidative stress, dry heat and photo stability testing conditions. The developed method can be used for the analysis of stability samples. Greenness assessment of developed method was performed using AGREE software. The method was found to be greener having greenness score of 0.69.

Analyzing the Effects of Monochromatic Lights on the Fungal Growth to Control the Progression of Microbial Deterioration on Animal Collections Preserved in the Zoological Museum of Naples, Italy

ABSTRACT Exposing artworks and artifacts in museums is fundamental to disseminate culture and knowledge but is also risky since the exposure to environmental conditions can deteriorate exhibited objects. Light is crucial, being able to trigger photochemical effects, and jointly responsible (with temperature and humidity) for biological risk generation. In this context, fungal growth in museum artifacts is a damaging factor that should not be underestimated. Consequently, the study of lighting effects on fungi development is essential. In this work, five different fungal strains (Aspergillus fumigatus, Bjerkandera adusta, Fusarium oxysporum, Penicillium chrysogenum, and Penicillium granulatum) isolated from samplings on animal exhibits hosted in the Zoological Museum of Naples, Italy, are cultivated inside four experimental boxes, equipped with monochromatic LEDs with different peak wavelengths (460 nm, 518 nm, 594 nm, and 638 nm). The growth rate, the protein and carbohydrate contents are analyzed and compared to results obtained in darkness (typical growth conditions for studies about fungi). Results demonstrate that, even if fungi are heterotrophic organisms and do not need light to grow and develop, their growth rate, and their protein and carbohydrate contents are affected by the exposure to monochromatic radiation, but the spectral sensitivity strictly depends on the analyzed species. For this reason, it is not possible to infer general practical guidelines for lighting applications, and it becomes urgent to establish accurate and shared analysis protocols to be applied case by case, to study the effects of the environmental conditions on microorganisms and drive-specific design choices.

Design of a liposome casein hydrogel as an efficient front-end homeostatic anthocyanin loading system

Proteins have been studied and applied to improve the stability of anthocyanins (ACNs), but the changes in the pH microenvironment during the preparation of steady-state systems are often ignored, and more attention is given to the stability of the system after preparation. In this study, we propose the “anthocyanin front-end homeostasis strategy”, which involves designing a system can protect anthocyanins under acidic conditions so that more anthocyanin prototypes can be loaded inside the protein. Anthocyanins are encapsulated in liposomes (Lip) at pH 3.0 and combined with casein methacrylate (CSMA) to form Anthocyanin-loaded liposomes/CSMA hydrogel (Lip@ACNs/CSMA), with good physical properties and good blood compatibility. The system increased the hydrogen peroxide scavenging capacity by 1.16 mg Vc equiv./mg ACNs and the cellular antioxidant activity by 17.55 μM quercetin/100 mg ACNs, the photo and thermal storage stability increased by 36.50 % and 30.71 %, the digestive rate increased by 17.50 %, and the biological availability increased by 0.0049 mg/mL. This study designed a liposome casein hydrogel as an efficient front-end homeostatic anthocyanin loading system and provided a new approach for improving the stability of anthocyanins.