The biodegradation of waste tyre rubber (WTR) is hindered by the presence of sulfur and additives, which limit microbial mineralization of the rubber polymers. To overcome this constraint, a hybrid chemi-biological approach is developed, wherein pretreatment with a reusable choline chloride/urea (ChCl/Ur) deep eutectic solvent (DES) is employed. Ground tyre rubber (GTR) is subjected to DES-assisted thermochemical pretreatment, followed by biological treatment using the Rhodococcus rhodochrous RPK1 bacterial strain in mineral salts medium for 28 days. The DES pretreatment significantly enhances biodegradation efficiency, resulting in a significant improvement over biological treatment alone. Structural, elemental, and thermal analyses confirm partial devulcanization, cleavage of sulfur crosslinks, removal of zinc additives, and reduced thermal stability. Crosslink density decreased by 43.6%, and Horikx analysis indicates a mixed degradation mechanism. The results demonstrate that DES pretreatment effectively reduces limiting factors, thereby improving rubber bioavailability. This hybrid strategy provides a viable framework for enhancing the biodegradation of WTR and supports a sustainable rubber recycling pathway.

Deep Eutectic Solvents (DESs) have gained significance as a sustainable alternative to hazardous chemicals. This study focuses on the effective applicability and reusability of choline chloride and urea (ChCl/Urea) based DES, chosen for its non-toxicity, biodegradability, non-flammability, and economic viability, aligning with the principles of green chemistry, for the devulcanization and detoxification of waste tire rubber. Notably, this is the first ever study to characterize and demonstrate the reusability potential of a ChCl/Urea DES, thereby reducing the ecological footprint of the process without compromising its effectiveness in reducing sulphur and other additives without affecting the rubber polymeric chains. Extensive characterization techniques such as Nuclear Magnetic Resonance (NMR) spectroscopy, Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), Carbon, Hydrogen, Nitrogen and Sulphur (CHNS) analysis, crosslink density determination, thermogravimetric analysis (TGA), headspace autosampler gas chromatography-mass spectroscopy (HS-GC/MS), and pyrolysis- gas chromatography-mass spectroscopy (Py-GC/MS) confirm the efficiency of spent DES and effective removal of sulphur, zinc and other additives while maintaining the rubber polymeric structure. The results show 30.86 % and 32.93 % total sulphur reduction, 89.83 % and 92.58 % zinc reduction, and 85.32 % and 66.67 % vulcanization accelerator reduction from waste tire rubber (WTR) using ChCl/Urea DES and spent ChCl/Urea DES, respectively. Moreover, the study confirms the biocompatibility and biodegradability of the ChCl/Urea DES. The presented process offers a scalable and environmentally benign alternative to conventional methods.

Antibiotics are used to treat both humans and animals for both preventive and therapeutic purposes. The overreliance on and misuse of antibiotics has given rise to a stealth pandemic, known as antimicrobial resistance (AMR). Globally, they pose a significant threat to human, animal, and environmental health. Surveillance of antibiotic residues in the environment, especially in wastewater, for tackling AMR can be a potent way to tackle deaths associated with AMR. Aquatic ecosystems are ideal habitats for the dissemination of AMR because they are frequently impacted by anthropogenic activities. Nearly half of the world's population resides in rural areas, which lack the infrastructure and resources necessary to manage wastewater effectively and sustainably. In the past decade, there has been no significant addition of new antibiotics. In this review, we discuss emerging enzyme-based biosensor technologies for on-site and rapid determination of antibiotics in the environment, with a focus on optical, electrochemical, and thermometric methods of detection.

White blood cells (WBCs) are key immune cells that defend against infections and regulate immunity. For accurate diagnosis, WBCs must be separated from red blood cells (RBCs), which can interfere with analysis. Microfluidic methods provide an efficient solution for high-purity WBC isolation, utilizing miniaturized devices that need minimal blood and enable on-chip disease detection and cell counting, thus enhancing point-of-care accessibility. This review focuses on passive microfluidic techniques, known for their simplicity and scalability, which separate WBCs by leveraging factors like RBC concentration, channel geometry, and flow dynamics. The low WBC-to-RBC ratio (1:1000) remains a major challenge, with few current technologies integrating WBC isolation and disease detection. This work emphasizes the principles and applications of passive separation methods and examines biological assays of isolated WBCs. Additionally, we discuss commercial devices and highlight opportunities for innovation in microfluidic platforms to address existing gaps, particularly in improving diagnostic efficiency and usability. By advancing versatile and user-friendly technologies, microfluidic systems have the potential to revolutionize point-of-care diagnostics and healthcare delivery.

The present work describes a microfluidic device developed for separating white blood cells (WBCs) for the Nitroblue Tetrazolium (NBT) bioassay, which quantifies the phagocytic ability of cells. The NBT test requires a small number of phagocytic cells but is highly susceptible to the presence of red blood cells (RBCs). Our inertial microfluidic device can deliver a WBC sample by removing 99.99

White blood cells (WBCs) are robust defenders during antigenic challenges and prime immune cell functioning indicators. High-purity WBC separation is vital for various clinical assays and disease diagnosis. Red blood cells (RBCs) are a major hindrance in WBC separation, constituting 1000 times the WBC population. The study showcases a low-cost micropump integrated microfluidic platform to provide highly purified WBCs for point-of-care testing. An integrated user-friendly microfluidic platform was designed to separate WBCs from finger-prick blood (⁓5 μL), employing an inertial focusing technique. We achieved an efficient WBC separation with 86

Our immune system is shielded from various pathogens by white blood cells (WBCs), which work as soldiers. WBCs reach the infectious site and kill the invading pathogens. The assessment of WBC activity and function is important in various diseases such as cancer, HIV, and autoimmune disorders; hence their separation is essential. The present study describes a method for WBC separation using the inertial microfluidic technique. A simple spiral microfluidic device with one inlet and three outlets is constructed here for WBC separation. The device functions on a diluted blood sample. Only 2 finger-pricked droplets of blood ( 20 µl) are required to prepare the minute volume of a diluted blood sample. A syringe pump is used to infuse the sample into the channel reservoir. The microdevice takes less than 22 s for WBC separation. We report WBC separation efficiency of nearly 90

White blood cells (WBCs) are crucial biomarkers for various chronic inflammatory diseases and need to be separated with a high purity for accurate disease diagnosis. WBC separation remains a challenging task due to abundant red blood cell (RBC) population affecting various bioassays. This letter emphasis on efficient WBC separation from diluted human blood using a microfluidic platform. Herein, we reported a simple spiral polydimethylsiloxane (PDMS)-based microfluidic device, comprises single inlet with multiple outlets to remove the highly abundant RBCs. The microdevice employs an inertial focusing technique for separating WBCs that can be subsequently utilized for on-chip myeloperoxidase (MPO) assay. The MPO enzyme is an inflammatory biomarker signifying oxidative stress and inflammatory status during disease progression. The microdevice can provide a WBC sample by eliminating 99.99% RBCs and subsequently decreasing the ratio of RBCs to WBCs from 850:1 to 3:1, which is sufficient for bioassays, such as MPO. Our simple spiral microfluidic device is easy to fabricate and simple to operate. The microdevice needs only a drop of unprocessed blood ( $\sim\!5 \,\mu l$ ) acquired by the finger-prick technique for an MPO assay. This microfluidic system can potentially translate into numerous point-of-care applications that need a high-purity WBC sample.

This paper discusses the finite element method (FEM) based performance analysis of serpentine electrodes (SREs) and interdigitated electrodes (IDEs) used for biochemical sensing applications. The SREs and IDEs structures were modelled for comparison with 20 mm (width, gap), length of 1 mm and 20 electrode pairs. The modelled SREs structure was analyzed with three diverse meshing techniques such as normal, fine, and adaptive mesh refinement (AMR). The skewness of 0.83 was found for AMR as against 0.64 and 0.57 of fine and normal mesh, respectively. Further, the electrical parameters such as signal strength, penetration depth, and electric field strength were considered to evaluate the performance of SREs and IDEs. Through simulation results, the signal strength of 4.92 pF was obtained for SREs as against 2.98 pF of IDEs. The penetration depth of 53.3 mm above electrode surface for SREs as against 26.7 mm of IDEs was obtained. Additionally, the FEM simulations were conducted for various substrate materials such as glass, FR4, Kapton (R) HN, and PET. Finally, a surface conductivity model in COMSOL (R) multiphysics was used to see the response from SREs and IDEs for varying conductivity between 0.0041 mS/cm to 12.9102 mS/cm. From simulation results, a decrease in impedance with increase in conductivity was observed validating the sensing mechanism. Moreover, a higher percentage change in impedance response was found for SREs as against IDEs for the same conductivity. Hence, this work demonstrates the importance of meshing while modelling complex electrode structures such as SREs. All the performance indicators suggest the usefulness of SREs over IDEs for biochemical analysis. Copyright (C)& nbsp;2022 Elsevier Ltd. All rights reserved.& nbsp;

How many nanoparticles can we load in a fiber? How much will leak? Underlying is the relatively new question of the "space available" in fibers for nanoparticle loading. Here, using supercritical carbon dioxide (scCO2) as a carrier fluid, we explored the impregnation in four Indian silks (Mulberry, Eri, Muga, and Tasar) with five standard sizes of gold nanoparticles (5, 20, 50, 100 and 150 nm in diameter). All silks could be permanently impregnated with nanoparticles up to 150 nm in size under scCO2 impregnation. Accompanying structural changes indicated that the amorphous silk domains reorganized to accommodate the gold NPs. The mechanism was studied in detail in degummed Mulberry silk fibers (i.e., without the sericin coating) with the 5 nm nanoparticle. The combined effects of concentration, time of impregnation, scCO2 pressure, and temperature showed that only a narrow set of conditions allowed for permanent impregnation without deterioration of the properties of the silk fibers.

Background: A rapid and specific detection of pathogens is of great importance from public health viewpoint as well as from economic perspectives. Genosensor based on sequence specific detection of Escherichia coli facilitates significant improvements in rapidity and specificity over traditional microbiological methods. Objective: The present study was aimed at identifying a sequence of xanQ genetic markers for designing the DNA sensing probe and fabricating a genosensor using the interdigitated gold electrode (IDE). A label-free genosensor for E. coli detection in water by a novel nucleic acid sensing probe, URecA1016 is reported. The URecA1016 sensing probe-functionalized gold-interdigitated electrode surface by covalent coupling using 11-Mercaptoundecanoic acid (crosslinker) to develop the electrochemical genosensor. Results: Upon DNA hybridization, the non-Faradaic sensing measurements showed a decreasing capacitance value with 10 min response time at 120 Hz frequency and 10 mV applied potential. The linearity range of the genosensor was between 1 and 1000 pg/mL for DNA of E. coli with a limit of quantification (LoQ) of 1.27 pg DNA/mL of E. coli (equivalent to approximately 150 CFU/mL) at 95 % confidence. Whilst the genosensor was E. coli species-specific as has been tested for the detection of E. coli MTCC 3221, E. coli O157:H7 ATCC 43895, E. coli O78:H11 MTCC 723 any cross-reactivity could not be observed with DNA of Shigella flexneri MTCC 9543 and Bacillus subtilis MTCC 736. The capacitance change responses were also recorded and discussed. Conclusions: The URecA1016 sensing probe was found to be specific for the detection of different E. coli species spiked in water. The results obtained in our study demonstrated the possible application potential of genosensor for E. coli detection in real water samples.

In past few years, the use of portable sensing technology has been steadily increasing in human health and well-being monitoring. Conventional methods used in healthcare diagnosis involve high cost, competent personnel and long analysis time. Wherein, electrical biosensor is considered as an obvious choice in diagnostic applications due to its ease of use, reasonable cost, portability for screening and online monitoring. In addition, sensitive, selective, and real-time on-site detection of targets in various matrices without the sample preparation could be achieved using electrical biosensors. Over the years, various transducer devices have been used for the development of electrical biosensors such as microelectrodes, interdigitated electrodes, field-effect transistors, and etc. This chapter describes the importance of various devices used in electrical biosensor for diagnostic applications. It also covers the advancements in electrical biosensor extended to realize wearable, wireless, internet of things (IoT), and machine learning based diagnostics.

Acetylcholinesterase (AChE), a widely used enzyme for inhibition-based biosensors in pesticide residues detection, lags due to multiple-step operation, time-consuming incubation and reactivation/regeneration steps. Herein, this endeavour reports the development of Organophosphate Hydrolase (OPH), which has functional superiority over the AChE and explored in on-spot biosensing device for organophosphate pesticide residue detection in fruits and vegetables. The organophosphate degrading enzyme OPH is expressed from the 'opd' gene through biotechnological tools. The OPH exhibited its best activity at pH 8.0 and subsequently thermal inactivation over 37 degrees C. The activity of the purified OPH enzyme was found 2.75 U mL(-1) at lambda(max) 410 nm. Furthermore, the developed OPH is integrated into 96 well plate format with our previously reported UIISScan 1.1, an advanced imaging array technology based field-portable high-throughput sensory system. The developed biosensor revealed a linear range from 100 ng mL(-1) to 0.1 ng mL(-1) for detection of organophosphate pesticide residues with a negative slope i.e. y = 235.678x (ng mL(-1)) - 62.8725 with R-2 = 0.99991 and n = 23. Moreover, the applicability of the developed biosensor was tested for market available fruits and vegetables. This is the first-ever reported OPH mediated on-spot biosensing device for pesticide residue detection in fruits and vegetables to the best of our knowledge.

Chemiluminescence signal amplification (CLSA) is of huge interest because of its sensitive detection in various applications such as food analysis, biomedical diagnosis and environmental monitoring. Due to this, there is a manifold attention to develop rapidly prototyped and miniaturized devices for CLSA. In this context, herein, a novel CLSA approach is demonstrated on a 3D printed microfluidic paper-based analytical device (μPADs), fabricated using Fused deposition modeling (FDM) printing technology. Influence of working temperature, ranging 30 °C-110 °C, on CL signal generation from well-established Luminol/Co+2 - H2O2 reaction was analyzed using a screen-printed flexible heater onto the 3D printed reaction platform. A smartphone-based capturing/detection system provided the amenability for a point-of-care testing system. For the first time, strong and stable CLSA was found with about 255% ± 5% increase in its signal intensity without using any additional external enhancers. The on-site working temperature was directly in proportional to the intensity of CL signal generated from Luminol/Co+2 - H2O2 reaction under optimum conditions, wherein the device had a wide linear range from 50 nM to 1 μM with a detection limit of 35 nM for H2O2 detection. The reliability of the developed amplification method was tested for practicability to detect the concentration of H2O2 in milk as real sample analysis. Overall, such CLSA mechanism in miniaturized μPADs will have strong potential for multiple CL based detection and monitoring application.

A colorimetric paper-based enzyme-coupled antimony tin oxide nanoparticle (ATONP) nanobiosensor for selective detection of Cd2+ ions in clams and mussels is presented. Alkaline phosphatase (ALP) was immobilized on ATONPs via 16-phosphonohexadecanoic acid (16-PHA) to develop ATONP-ALP nanobiosensor. The biosensor was characterized using XPS, Raman spectroscopy, SEM, and EDX. ATONP-ALP nanobiosensor exhibited high selectivity towards detection of Cd2+ ion with a LOD 0.006 μg L−1 and linear range of detection 0.005–1 μg L−1. The developed biosensor was further integrated into a low-cost paper-based format. A visual color change was obtained for Cd2+ ion in the range 0.1–10 μg L−1. The developed biosensor was successfully demonstrated for the analysis of Cd2+ ions in clams with recoveries 101–104%. The ATONP-ALP nanobiosensor was validated using mussel tissue (BCR-668) and the conventional ICP-OES and ICP-MS techniques.

This paper investigates the effect of metallization ratio and side shift on the performance of interdigitated electrodes (IDEs). The IDEs were modelled using normal mesh and adaptive mesh refinement techniques to investigate the modelling error. The performance parameters such as electric field distribution, crosstalk and penetration depth of IDEs and the phenomenon of impedance biosensor based on surface conductivity model was simulated using COMSOL Multiphysics software. A detailed analysis was carried out to see the effect of metallization ratio on these performance parameters. In the simulation, the metallization ratio of IDEs was varied between 0.2–0.9, and the variation in side shift was 1–50 µm. A significant reduction in modelling error was obtained for adaptive mesh refinement (AMR) based IDEs model. The IDEs with metallization ratio 0.7 and side shift between 10–20 µm have shown higher measurement sensitivity. For validation of simulation results, experiments were conducted on fabricated IDEs with different metallization ratios. IDEs with metallization ratios 0.3, 0.5 and 0.7 were fabricated using PCB technology. The impedance spectra were obtained for a 10–100 mM KCl solution using electrochemical impedance spectroscopy (EIS). Through simulation and from experimental results, higher measurement sensitivity from IDEs was obtained at 0.7 metallization ratio. Finally, this paper demonstrates the importance of metallization ratio and side shift to ensure higher measurement sensitivity from IDEs when used for biochemical sensing applications.

Background and Objectives: Public health protection requires timely evaluation of pathogens in potable water to minimize outbreaks caused by microbial contaminations. The present study was aimed at assessing the microbiological quality of water obtained from Shantinagar (a rural area in the South Goa region of Goa, India) using 5-Bromo-4-Chloro-3-Indoxyl β-D-glucuronide-Sorbitol MacConkey agar (BCIG-SMAC) medium and, propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR) assay for differential detection and quantification of viable Escherichia coli cells in water samples. Materials and Methods: Membrane filtration method was used for both BCIG-SMAC medium and PMA-qPCR methods. To determine the efficiency of detection of viable cells, we first evaluated the PMA treatment protocol and established the standard calibration curves using previously reported primers. Results: PMA-qPCR detected as low as 7 femtograms of DNA of E. coli per qPCR reaction whereas the limit of detection (LOD) of BCIG-SMAC medium was 1.8 CFU/100mL. A total of 71 water samples spanning 2017-2018 have been analyzed using BCIG-SMAC medium and PMA-qPCR, of which 95.77% (68/71) and 7.04% (5/71) were found to be total E. coli and E. coli O157:H7, respectively. PMA-qPCR study showed the viable counts of total viable E. coli cells ranging from 3 CFU/100mL to 8.2×102 CFU/100mL. The total E. coli CFU/100mL quantified by PMA-qPCR significantly exceeded (paired t-test; P<0.05) the number on BCIG-SMAC medium. Conclusion: The present study indicates that the microbiological quality of environmental water samples analyzed do not comply with the regulatory standard. Therefore, special attention is warranted to improve the overall portable quality of water in the perspective of public health.

A Polytyramine-alkanethiol based electrochemical capacitive immunosensor was developed for tetracycline (TC) antibiotic detection in water. Tyramine (TA) monomer was electropolymerized to get an insulating ultrathin polytyramine (PTA) film on the gold-coated silicon electrode (AuE). The PTA coated AuEs were incubated in 1Dodecanethiol to get thiol filled polymer-coated electrodes. This process of thiolation filled the pinholes of the polymer surface and enhanced the insulation of the polymer electrode, suited for capacitive sensor development. The thiolated polymer electrodes weremodified with polyclonal antibodies against TC to get TC immunosensor (TCI). The prepared TCI was characterized at various steps of fabrication. The surface characterization was performed by using an atomic force microscope (AFM). The electrochemical characterizations were performed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) technique. Further, the EIS measurements were carried out to measure the capacitance change of TCI in the presence of TC in matrix-matched water samples. The fabricated TCI exhibited linearity in 1 to 200 mu gL(-1) range for TC, with a limit of detection 0.01 mu gL(-1). Further, the fabricated TCI exhibited good selectivity towards TC with recovery from 96 to 102% in spiked water samples. Results indicate the possible application of developed immunosensor for TC estimation in water samples.

We report a label-free biosensor for the detection of Escherichia coli O157:H7 ATCC 43895 in potable water using a newly designed DNA sensing probe targeting the z3276 genetic marker. The surface of indium tin oxide (ITO) was functionalized with the novel sensing probe by covalent coupling using APTES as a crosslinker to fabricate the DNA sensor (dubbed ZEC [z[combining low line]3276 gene of E[combining low line]. c[combining low line]oli O157:H7 ATCC 43895]). The electrochemical characterization of the fabricated ZEC sensor was performed using cyclic voltammetry and electrochemical impedance spectroscopy. Atomic force microscopy and scanning electron microscopy revealed significant changes in the surface topographies of the fabricated ZEC sensor chip. Equivalent circuit analyses suggested the capacitive nature of the ZEC sensor chip, which demonstrated a declining trend of the capacitance value from 1.568 μF (Bare ITO) to 1.221 μF (after DNA hybridization). Non-faradaic sensing measurements revealed systematically declining capacitance values upon DNA hybridization, with a 10 min response time at 10 Hz frequency and 10 mV applied potential. The ZEC sensor chip exhibited linearity in the range of 0.5 to 25 pg per 10 mL for E. coli O157:H7, with ubiquitous cross-validation of each DNA concentration using quantitative PCR prior to the analyses of real water samples. The limit of detection (LOD) at 95% confidence estimated by logistic regression was 0.1 pg DNA per 10 mL of E. coli O157:H7 (equivalent to 13.67 CFU per 10 mL) with a p-value of 0.0237. Consequently, the obtained results demonstrate the possible application of the developed ZEC sensor chip for E. coli O157:H7 detection in real water samples.