Bio Applications Research Articles

Active plasmonic nanodevices: From basic principles to emerging applications

AbstractTunable plasmonics has shown a wide range of applications in (bio)chemical sensing, displays, actuators, photonic chips, biomedicine, etc. in the last 2 decades. This review focuses on their recent development from the device perspective, which involves the understanding of fundamental principles and specific applications with desired functionality and compatibility. We classify these active plasmonic devices based on the nature of their structures and working environment as colloidal‐based, chip‐based, and colloidal chip‐based to further elaborate their performance and functions. We also highlight recent progress on tunable surface‐enhanced Raman spectroscopy, metasurfaces, and chiroptics to show the emerging applications of tunable plasmonic systems. We conclude this review with a general perception of the research trend in this field and challenges for their practical applications.

Toxicity optimization of green zinc oxide quantum dots in zebrafish using Box-Behnken design: a novel approach for safer nanoparticle synthesis

Zinc oxide quantum dots, also known as ZnO QDs, are highly desirable due to their numerous favorable characteristics, such as their beneficial photoluminescence, solubility in water, along with sunlight absorption. They are well-suited for use in biomedical applications, drugs, and bioimaging. However, study on the in-vivo toxicology of these QDs is needed before they can be used in humans. Zebrafish (Danio rerio) are cheap, fast-growing, and similar to humans, which makes them ideal as in vivo model for studying the toxicity of nanomaterials. The toxicity investigations involving zinc oxide QDs (ZnO QDs) and zinc oxide bionanocomposite (ZnO BC) in zebrafish that were concentration-dependent are evaluated, and the Box-Behnken design (BBD) was utilized to optimize the results. To determine the proper dosage, a study on cell line as well as hemocompatibility was carried out prior to testing the toxic effects of ZnO QDs along with ZnO BC upon zebrafish. When administered at 2.5 μg/l of ZnO BC and 2 μg/l of ZnO QDs, neither ZnO BC nor ZnO QDs appeared to be toxic to embryos during hatching and development. The testing of larval behavior in visible light revealed a dose-dependent decrease in both the total diving distance as well as speed. Nevertheless, at ZnO BC and ZnO QDs levels >250 μg/l and >200 μg/l, respectively, notable effects were seen in zebrafish embryos. Hence, ZnO QDs and BC at low concentrations were notably nontoxic. In order to guarantee the safety of nanomaterials in bio applications, this research supports upcoming in-vivo imaging investigations on their harmful effects.

HIV deathrate prediction by Gaidai multivariate risks assessment method.

HIV is a contagious disease with reportedly high transmissibility, being spread worldwide, with certain mortality, allegedly presenting a burden to public health worldwide. The main objective of this study was to determine excessive HIV death risks at any time within any region or country of interest. Current study presents a novel multivariate public health system bio-risk assessment approach that is particularly applicable to environmental multi-regional, biological, and public health systems, being observed over a representative period of time, yielding reliable long-term HIV deathrate assessment. Hence, the development of a new bio-statistical approach, that is, population-based, multicenter, and medical survey-based. The expansion of extreme value statistics from the univariate to the bivariate situation meets with numerous challenges. Firstly, the univariate extreme value types theorem cannot be directly extended to the bivariate (2D) case, - not to mention challenges with system dimensionality higher than 2D. Existing bio-statistical methods that process spatiotemporal clinical observations of multinational bio-processes often do not have the advantage of efficiently dealing with high regional dimensionalities and complex nonlinear inter-correlations between different national raw datasets. Hence, this study advocates the direct application of the novel bio-statistical Gaidai method to a raw unfiltered clinical data set. This investigation described the successful application of a novel bio-risk assessment approach, yielding reliable long-term HIV mortality risk assessments. The suggested risk assessment methodology may be utilized in various public bio and public health clinical applications based on available raw patient survey datasets.

Zero-crosstalk silicon photonic refractive indexsensor with subwavelength gratings.

Silicon photonic index sensors have received significant attention for label-free bio and gas-sensing applications, offering cost-effective and scalable solutions. Here, we introduce an ultra-compact silicon photonic refractive index sensor that leverages zero-crosstalk singularity responses enabled by subwavelength gratings. The subwavelength gratings are precisely engineered to achieve an anisotropic perturbation-led zero-crosstalk, resulting in a single transmission dip singularity in the spectrum that is independent of device length. The sensor is optimized for the transverse magnetic mode operation, where the subwavelength gratings are arranged perpendicular to the propagation direction to support a leaky-like mode and maximize the evanescent field interaction with the analyte space. Experimental results demonstrate a high wavelength sensitivity of - 410nm/RIU and an intensity sensitivity of 395dB/RIU, with a compact device footprint of approximately 82.8μm2. Distinct from other resonant and interferometric sensors, our approach provides an FSR-free single-dip spectral response on a small device footprint, overcoming common challenges faced by traditional sensors, such as signal/phase ambiguity, sensitivity fading, limited detection range, and the necessity for large device footprints. This makes our sensor ideal for simplified intensity interrogation. The proposed sensor holds promise for a range of on-chip refractive index sensing applications, from gas to biochemical detection, representing a significant step towards efficient and miniaturized photonic sensing solutions.

Fluorescent cellulose nanofibrils hydrogels for sensitive detection and efficient adsorption of Cu2+ and Cr6+

Increasing chromium and copper pollution poses a significant threat to the global environment and human health. It is crucial to detect and remove Cu (II) and Cr (VI) from water. Cellulose nanofibrils (CNF)-based hydrogels were a natural, abundant, and biocompatible material that has attracted great attention for bio adsorption applications. In this work, a new fluorescent CNF-based hydrogel (PAA-CNF-W) was prepared for the high-efficiency adsorption and sensitive detection of Cu (II) and Cr (VI). CNF was introduced as a natural backbone to construct a three-dimensional porous structure, which increased the specific surface area and provided additional active sites, exhibiting excellent adsorption properties for Cu (II) (159.24 mg/g) and Cr (VI) (173.87 mg/g). Moreover, the synthesized dansyl chloride derivatives with fluorescent properties were introduced to the hydrogel and formed chelates with the metals leading to fluorescence quenching. PAA-CNF-W hydrogels showed high sensitivity to the detection limit (LOD) of Cu (II) (28.70 mg/L) and Cr (VI) (1.45 mg/L). The kinetic study revealed that pseudo-second order kinetics was the best-fitting model. The Langmuir isotherm was the best adjustment model. The study provides a new idea for efficient detection and removal of Cu (II) and Cr (VI) from wastewater by cellulose materials.

Photodegradable glyco-microfibers fabricated by the self-assembly of cellobiose derivatives bearing nitrobenzyl groups

Stimuli-responsive materials constructed via the self-assembly of small biomolecules are attracting increasing attention because of their biocompatibility, sustainability, and variety of (bio)applications. Nevertheless, the research on oligosaccharide-based molecular designs for such stimuli-responsive materials (or stimuli-responsive glyco-materials) is limited, partly due to the intrinsic structural diversity of oligosaccharides and the difficulty associated with their selective chemical syntheses. Herein, we report the construction of photodegradable glyco-microfibers by the self-assembly of cellobiose derivatives bearing nitrobenzyl groups. The atomic-scale, self-assembled architecture of the photodegradable glyco-microfibers is unveiled and compared with those of pristine cellobiose and cellulose polymorphs in previous reports.

Silver-doped ZrO2-TiO2 nanocomposite coatings on 316L stainless steel for enhanced corrosion resistance and bio applications

The demand for ceramic based nanocomposite coatings has increased because they play a significant role in orthopedic implants and medical devices. Ceramic nanocomposites are inert and highly biocompatible, which improve corrosion resistance under physiological fluids. The ceramic nanocomposites were deposited (silver-doped ZrO2/TiO2) on SS 316L, and their biocompatibility, strength of adhesiveness, and corrosion resistance properties were studied. A detailed investigation of corrosion resistance, wettability, and biocompatibility concerning microstructures and the inclusion of silver as a dopant was conducted. The deposited films annealed at 600 °C display crystallinity with the coexistence of TiO2 rutile and ZrO2 monoclinic phases. The surface morphology shows the average particle size on thin film is around 40 to 45 nm. The deposited films show a decreased corrosion current density (ICorr) in potentiodynamic polarization curves, confirming the adequate protection against corrosion using simulated body fluid and phosphate buffer saline at 37±1 °C. The surface wettability of coatings is hydrophilic, and it improves in-vitro compatibility. The apatite growth in SBF solution on the implant surface predicts a favorable condition for bone regeneration in the patient's body. The effect of silver dopant on improving apatite growth on implant surface is also discussed. From electrochemical impedance spectroscopy, the diameter of the semicircle in the Nyquist plot shows more than bare metal; the higher the diameter indicates the more resistive behavior of deposited films, which shows the effective corrosion resistance in the electrolytic solution. It is found that the biocompatibility and corrosion resistance are improved compared with bare SS 316L. Hence, ceramic nanocomposite coatings show great potential in the orthopedic implant industry.

Feedthrough Engineering to Enable Resonant Sensors Working in Conductive Medium for Bio Applications

Feedthrough Engineering to Enable Resonant Sensors Working in Conductive Medium for Bio Applications

Multi-membranes-based pumping flow of nanofluids: Application in thermofluidic system

Microscale heat transfer plays a crucial role in various smart thermal devices such as microchannel heat sinks, micro heat pipes, and thermosyphons, as well as in bio microfluidics applications where biological fluids are being transported via natural pumping mechanisms. Inspired by the importance of microscale heat transfer, a biothermal-based pumping flow model integrating membrane-based pumping mechanism and nanofluids is developed mathematically. A Ghost-Valve model for membrane pumping is adopted based on Yasser’s model. Conservation principles for mass, momentum, energy, and nanoparticle volume fraction are considered for the mathematical formulation. The main objectives of this bio-thermo-physical model are to provide insights into pressure gradients, velocity distributions, volumetric flow rates, shear stress, streamlines, isotherms, nanoparticle volume fraction, Nusselt number, and Sherwood number under the effects of key parameters. Additionally, entropy generation analysis is presented with variation of thermal Grashof number, basic density Grashof number, Brinkmann number, and relative temperature on system performance. An analytical approach has been employed to derive the solutions under low Reynolds number approximation, and results are computationally analyzed using MATLAB code. Our findings highlight the effectiveness of membrane-based pumps in controlling microfluidic flow and heat transfer within microchannels and it is reported that velocity field enhances in magnitude with increasing the time phase lag parameter. This model will also present a benchmark for various future models to be developed for the nanofluids flow with various combinations of nanoparticles and base fluids through various flow regimes to be utilized for various purposes of the thermal systems/energy systems and offering valuable insights for optimizing thermal-based pumping systems in microscale applications.

معجل ثالثي مستدام لفلكنة الكبريت لمطاطي ال NR و ال SBR من مستخلص اوراق شجرة

تم تحضير معجل جديد, طبيعي, رخيص, ومتاح يستخدم في انظمة فلكنة المطاط الطبيعي NR)) و مطاط الستايرين بيوتادايين ((SBR وقد تم تحضير هذا المعجل من المخلفات الزراعية. حيث تم اضافة مسحوق مجفف لمستخلص من اوراق شجرة الكينوكاربس لانسيفوليوس Conocarpus lancifolius بالنسب المئوية التالية: 0.5, 1.0, 1.5, 2.0) wt%) الى العجينة الرئيسية لمطاطي ال NR و ال SBR والتي تحتوي على معجلات البنزوثايوزول (MBT, MBTS). تم اختيار مستخلص CLLE)) نظرًا لاحتوائه على مركبات الفلافونويد, السابونين و الفينولات داخل هيكلها، مما يعزز الترابط الهيدروجيني (H-bond) كرابطة ثانوية ، والتي بدورها تعزز معدل المعالجة. اظهرت النتائج قابلية مستخلص CLLE)) على تعجيل (curing systems)نظامي الفلكنة المذكورين حيث كان التركيز الامثل مع مطاط ال 0.5( pphr) SBR والتركيز الامثل لمطاط ال NR 1 (pphr) . وكان تأثير هذا المستخلص على نظام معالجة مطاط NR اكبر من مطاط ال SBR حيث انخفض زمن الانضاج الامثل Tc90 لمطاط ال SBR بمقدار (2.42 %) في حين انخفض بمقدار 17.74 % لمطاط ال NR , اما بالنسبة لمؤشر معدل النضوج (CRI) فقد ازداد في مطاط ال SBR بمقدار 5.9 % فقط, في حين انه ازداد بمقدار 24.83 % لمطاط ال NR. بالإضافة الى ذلك فان اضافة مستخلص CLLE)) قد عملت على تقليل زمن الاحتراق (ts2) ولكلا المطاطين. وكانت قيم ال ts2 لعينات مطاط ال SBR اكبر من قيم ال ts2 لعينات مطاط ال NR. كما بينت النتائج ان اضافة CLLE)) لم تؤثر على قيم مقاومة الشد وكان هناك انخفاض طفيف في قيمة الصلابة وزيادة في معامل الاستطالة عند (300%) وزيادة في قيم الاجهاد و الانفعال قبل الفشل. أدت إضافة CLLE إلى زيادة معدلات المعالجة بسبب احتوائها على مكونات نشطة (الفلافونويد والسابونين والفينولات) ، والتي شجعت على استخدام هذه المنتجات المرنة للتطبيقات الحيوية وتعمل كعامل اقتران للبوليمرات المحبة للماء والطارئة للماء.

Rapid millisecond heating via ferromagnetic resonance in MnFe2O4 nanoparticles

This study undertakes an exhaustive analysis of rapid heat generation in MnFe2O4 nanoparticles through ferromagnetic resonance within an ultra-fast timeframe of 1 ms. Real-time monitoring of temperature during single-field-pulse excitations provided detailed insights into the temperature rise profiles. By integrating micromagnetic simulations with analytical modeling—taking into account both convective and radiative losses—we have deepened our understanding of the heat transfer dynamics at play. Adjusting the analytical model to align with experimental temperature profiles enabled us to determine the efficiency of converting spin dissipation energy into heat, which stands at 17%. This figure reflects not only the surface area of the nanoparticles but also includes considerations for radiative and convective losses. Notably, employing a low AC-field strength of 17.6 Oe facilitated a rapid temperature increase of up to 90 K in just 0.5 s, showcasing a peak initial temperature rise rate of approximately 680 K/s. This research advances the frontiers of high-power heat generation driven by spin dynamics and provides a comprehensive exploration of heat transfer mechanisms over exceptionally short pulse durations. These findings could revolutionize precise and rapid temperature management at the nanoscale, unlocking prospects in bio applications, accelerated material processing, and inducing color and phase shifts in polymer matrices.

Ultraviolet response data of liquid crystals for bioprocess monitoring: A methodical exploration

From the homologues series of 2,3-n-dialkyloxy-4-(4-chlorobenzoyloxy)-4′-(4-methylbenzoyloxy)-azobenzene (nOClAB; n = 5, 6, 7, 8) have been chosen for bioprocess monitoring based on their ultraviolet (UV) response. The optimization of molecular structures of these compounds has been performed via functional B3LYP together with 6–31+G (d) basis set. Further, the UV response of these compounds have been analyzed by implementing the configuration interaction singles (CIS) method along with calculation of excited states using semiempirical ZINDO Hamiltonian. The INDO/S+CI approach has been used for comparative analysis. Geometries of four liquid crystals (LCs) in the biosensing, their usefulness, as well as their applications are described. The spectral associated parameters have been summarized. Using this data the UV response mechanism and its implication in analyzing bioprocess monitoring, bio sensing, and bio oscillator applications have been methodically explored. These liquid crystal structures are expected to fulfill the purpose of the processors that can transform the biomolecule signals into the optical signals.

Zinc oxide nanoparticles exhibit anti-cancer activity against human cell lines

Zinc oxide nanoparticles have garnered tremendous interest in bio and nanomedical applications and more so in cancer research. In the present work, zinc oxide nanoparticles were synthesized using the solution combustion method and characterized by UV–vis spectroscopy, FTIR, XRD, SEM and EDX. The infrared spectrum of the synthesized nanoparticles had a peak at 547 cm−1 which indicated the elongation frequency of the zinc bond to oxygen. The XRD spectrum was confirmed with the ICDD Data Card No: 36-1451 for zinc oxide and the average size of zinc oxide nanoparticles was estimated to be 17.51 nm. Scanning electron microscopy confirmed the presence of zinc oxide nanoparticles as Zincite with a hexagonal structure having an average diameter of 30.95 nm. The DNA binding interactions of the nanoparticles were studied using the absorption titration method. The nanoparticles could bind via the non-intercalation mode with a binding efficiency of 3.563×105 M−1. The synthesized zinc oxide nanoparticles exhibited cytotoxic activity against the mammalian cancer cell lines tested with the calculated IC50 values being 3.66 µgmL−1 for MCF-7 (Breast), 2.91 µgmL−1 for LN-18 (Glioblastoma–Brain), 23.14 µgmL−1 for A-549 (Lung) and 94.33 µgmL−1 for SHSY-5Y (Neuroblastoma–Bone). The highest cell death was observed for LN-18 glioblastoma cells of the brain. The study demonstrated a simple and conventional method of synthesis of zinc oxide nanoparticles that have demonstrated anticancer activity as evidenced by the in vitro cell viability assays. The outcome of this study could be applied to develop zinc oxide nanoparticles as anticancer agents with further validation in vivo.

Application of (bio) chemical engineering concepts and tools to model genetic regulatory circuits, and some essential central carbon metabolism pathways in living cells. Part 4. Applications in the design of some Genetically Modified Micro-Organisms (GMOs)

In the first part of this work, the general Chemical and Biochemical Engineering (CBE) concepts and rules are briefly reviewed, together with the rules of the control theory of Nonlinear Systems (NSCT), all in the context of (i) deriving deterministic Modular Structured Kinetic Models (MSDKM) to describe the dynamics of metabolic processes in living cells, and (ii) of Hybrid Structured Modular Dynamic Models (HSMDM) (with continuous variables, linking the cell-nano-scale MSDKM state variables to the macro-scale state variables of the bioreactor dynamic model). Thus, in the HSMDM model, both prediction quality and its validity range are improved. By contrast, the current (classical/default) approach in bioengineering practice for solving design, optimization, and control problems based on the math models of industrial biological reactors is to use unstructured Monod (for cell culture reactor) or simple Michaelis-Menten (if only enzymatic reactions are retained) global kinetic models by ignoring detailed representations of metabolic cellular processes. By contrast, as reviewed, and exemplified in the second part of this work, an accurate and realistic math modelling of the dynamic individual GERMs (gene expression regulatory module), or genetic regulatory circuits (GRC), and cell-scale CCM (central carbon metabolism) key-modules can be done by only using the novel holistic ’Whole-Cell Of Variable-Volume’ (WCVV) modelling framework, under isotonic/homeostatic conditions/constraints introduced and promoted by the author. An example was given in the same Part 2 for the case study of a dynamic model for the oscillating glycolysis coupled with the Tryptophan (TRP) oscillating synthesis in the E. coli cells.

The deep learning applications in IoT-based bio- and medical informatics: a systematic literature review

AbstractNowadays, machine learning (ML) has attained a high level of achievement in many contexts. Considering the significance of ML in medical and bioinformatics owing to its accuracy, many investigators discussed multiple solutions for developing the function of medical and bioinformatics challenges using deep learning (DL) techniques. The importance of DL in Internet of Things (IoT)-based bio- and medical informatics lies in its ability to analyze and interpret large amounts of complex and diverse data in real time, providing insights that can improve healthcare outcomes and increase efficiency in the healthcare industry. Several applications of DL in IoT-based bio- and medical informatics include diagnosis, treatment recommendation, clinical decision support, image analysis, wearable monitoring, and drug discovery. The review aims to comprehensively evaluate and synthesize the existing body of the literature on applying deep learning in the intersection of the IoT with bio- and medical informatics. In this paper, we categorized the most cutting-edge DL solutions for medical and bioinformatics issues into five categories based on the DL technique utilized: convolutional neural network, recurrent neural network, generative adversarial network, multilayer perception, and hybrid methods. A systematic literature review was applied to study each one in terms of effective properties, like the main idea, benefits, drawbacks, methods, simulation environment, and datasets. After that, cutting-edge research on DL approaches and applications for bioinformatics concerns was emphasized. In addition, several challenges that contributed to DL implementation for medical and bioinformatics have been addressed, which are predicted to motivate more studies to develop medical and bioinformatics research progressively. According to the findings, most articles are evaluated using features like accuracy, sensitivity, specificity, F-score, latency, adaptability, and scalability.

Biosensing with Tailored Track-Etched Nanochannels

Inspired by the high sensitivity, efficiency and selectivity of biological ion channels, the development of solid-state nanochannel sensors has been at the forefront of nanotechnology research in the last years. Many researchers worldwide have concentrated their efforts on the development of artificial nanochannels that can mimic the features of biological ion channels. These synthetic nanostructures are based on abiotic materials which provide higher robustness, thermal stability, chemical versatility and mechanical resistance than their biological counterparts. Furthermore, synthetic nanochannels and specific surface functionalization strategies have enabled fine control over the geometry and charge distribution which yielded the ability to manipulate the flux of ions through the channel. This gave rise to the formation of nanochannel-based platforms with applications in (bio)sensing as well as other fields. The development of chemical- and biosensors requires a combination of reliable nanofabrication techniques and versatile surface modification strategies, which render high sensitivity and high selectivity, respectively [1].Tailored single polymer nanochannels are routinely fabricated by ion-track nanotechnology. Polymer films are first irradiated with individual swift heavy ions at the GSI UNILAC accelerator. Each ion generates a highly localized cylindrical damage zone along its trajectory. These so-called ion tracks are subsequently dissolved and enlarged in a chemical etching process. By selecting suitable etching conditions, geometry (cylindrical, conical or bullet-like) and size of the nanochannels can be adjusted. The nanochannel surface can then be functionalized by means of different chemical strategies to enhance the sensing capabilities.There are two main nanochannel sensing techniques, ion current rectification (ICR) and resistive-pulse sensing (RPS). Both are affected by the geometry and surface charge of the nanochannel and based on measuring the change in ion current flowing through the channel induced by the chosen analyte [2]. In both approaches, the presence of a target analyte triggers a variation in the physicochemical properties of the channel which can be related to measurable changes in the transmembrane current, and is proportional to the analyte concentration.In this contribution, we will present nanochannel sensing platforms based on several single polymer channels fabricated by ion-track nanotechnology and a selection of surface functionalization strategies applied to the nanochannels. We will then discuss selected examples recently obtained with these tailored functionalized nanochannels and demonstrate selective and sensitive sensing applications based on both the ICR and RPS phenomena.[1] Toum Terrones, Y., Cayón, V. M., Laucirica, G., Cortez, M. L., Toimil-Molares, M. E., Trautmann, C., ... & Azzaroni, O. (2022). Ion Track-Based Nanofluidic Biosensors. In Miniaturized Biosensing Devices: Fabrication and Applications (pp. 57-81). Singapore: Springer Nature Singapore.[2] Kaya, D., & Keçeci, K. (2020). Track-etched nanoporous polymer membranes as sensors: A review. Journal of The Electrochemical Society, 167(3), 037543.

The Autonomization Principle in Vascularized Flaps: An Alternative Strategy for Composite Tissue Scaffold In Vivo Revascularization.

Autonomization is a physiological process allowing a flap to develop neo-vascularization from the reconstructed wound bed. This phenomenon has been used since the early application of flap surgeries but still remains poorly understood. Reconstructive strategies have greatly evolved since, and fasciocutaneous flaps have progressively replaced muscle-based reconstructions, ensuring better functional outcomes with great reliability. However, plastic surgeons still encounter challenges in complex cases where conventional flap reconstruction reaches its limitations. Furthermore, emerging bioengineering applications, such as decellularized scaffolds allowing a complex extracellular matrix to be repopulated with autologous cells, also face the complexity of revascularization. The objective of this article is to gather evidence of autonomization phenomena. A systematic review of flap autonomization is then performed to document the minimum delay allowing this process. Finally, past and potential applications in bio- and tissue-engineering approaches are discussed, highlighting the potential for in vivo revascularization of acellular scaffolds.

Mach-Zehnder interferometer fiber optic sensor coated with UiO-66 metal organic framework for creatinine detection

An in-line Mach-Zehnder fiber optic sensor based is proposed and fabricated to measure creatinine (CR) concentration in the physiological range for clinical trials. The shift in valleys wavelength is monitored to assess the sensor response to the variation of CR concentration. Single-mode fiber as the sensing part is coated with UiO-66 metal–organic framework (MOF) adsorbent by dip coating to enhance the performance of the sensor. For further improvement, the length of the SMF and the coating time of the UiO-66 are optimized. The sensitivity and limit of detection (LOD) of the optimized bare sensor are 1530 pm/(mg/dL) and 0.4 mg/dL, respectively. The sensor with optimized UiO-66 coating thickness has a sensitivity of 2400 pm/(mg/dL) and an LOD of 0.2 mg/dL indicating the high performance. The sensors offer fast response, high sensitivity, and proper linear response at low concentrations of CR which reveal their potential in bio and chemical applications.

Nanothermometer Based on Polychlorinated Trityl Radicals Showing Two-Photon Excitation and Emission in the Biological Transparency Window: Temperature Monitoring of Biological Tissues.

Nanothermometers are emerging probes as biomedical diagnostic tools. Especially appealing are nanoprobes using NIR light in the range of biological transparency window (BTW) since they have the advantages of a deeper penetration into biological tissues, better contrast, reduced phototoxicity and photobleaching. This article reports the preparation and characterization of organic nanoparticles (ONPs) doped with two polychlorinated trityl radicals (TTM and PTM), as well as studies of their electronic and optical properties. Such ONPs having inside isolated radical molecules and dimeric excimers, can be two-photon excited showing optimal properties for temperature sensing. Remarkably, in TTM-based ONPs the emission intensity of the isolated radical species is unaltered increasing temperature, while the excimer emission intensity decreases strongly being thereby able to monitor temperature changes with an excellent thermal absolute sensitivity of 0.6-3.7%K-1 in the temperature range of 278-328K. The temperature dependence of the excimeric bands of ONPs are theoretically simulated by using electronic structure calculations and a vibronic Hamiltonian model. Finally, TTM-doped ONPs as ratiometric NIR-nanothermometers are tested with two-photon excitationwith enucleated pig eye sclera, as a real tissue model, obtaining a similar temperature sensitivity as in aqueous suspensions, demonstrating their potential as NIR nanothermometers for bio applications.

Extensive studies on the electrochemical, photocatalytic and antimicrobial applications of bio assisted nano titania

In recent days synthesis and structuring of intelligent nano materials investigated and reported has developed critical scientific ideas to deal with different industrial, social and environmental issues. The excellent thermal, optical and electrical properties along with its resistant to corrosion, wear, oxidation and erosion enabled them unique for sustainable environmental applications. In this view nano structured Titanium di oxide particles synthesized from its precursor via template assisted sol–gel technique have been verified as corrosion inhibitor of brass alloy in acid medium along with its photo catalytic and anti-microbial applications. The physico-chemical parameters of the synthesized nano materials were studied using XRD, FT-IR, UV-DRS, SEM, TEM and BET analytical techniques and revealed the impact of tea leaf extract as a template in producing a nano catalyst NTG about 14 nm in size with tailored structural, optical and morphological characteristics. The rate of corrosion of a specimen in acid medium is verified by weight loss method and the inhibitor efficiency increased with the increase in concentration of the nano catalyst. The catalytic activity is proved against the photo degradation of a toxic melamine, a trimer of cyanamide. The synthesized nano catalyst showed excellent antimicrobial properties proven against the growth of K. pneumonia and H. influenza.