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Microfluidic paper-based analytical devices (μPADs) attract tremendous attention as an economical tool for in-field diagnosis, food safety and environmental monitoring. We innovatively fabricated 2D and 3D μPADs by photolithography-patterning microchannels on a Parafilm® and subsequently embossing them to paper. This truly low-cost, wax printer and cutter plotter independent approach offers the opportunity for researchers from resource-limited laboratories to work on paper-based analytical devices. [ABSTRACT FROM AUTHOR]

Environmental Effects Monitoring (EEM) Programs in Canada have been developed for the pulp and paper and metal mining industries. The EEM Program conducts cyclical evaluations of receiving environments to determine whether effects exist when facilities comply with existing regulations. Investigation of cause (IOC) is a specific stage in the EEM Program that is used after environmental effects in fish and/or benthos have been detected, confirmed and their extent and magnitude have been documented. This paper presents an overview of the processes associated with this phase of monitoring. The objective of an IOC is to obtain sufficient information so that the source of the effect can be identified and removed, or its effects reduced to an acceptable level. The initial direction of an IOC is dependent upon the type of response patterns observed for fish and/or benthos during EEM cycles and extent/magnitude studies. The framework presented in this paper is based on an amalgamation of research projects conducted at Canadian pulp mills over the last decade and selected studies are summarized as examples. It also represents an integration of several research philosophies and scientific disciplines. The framework is based on national response patterns from the second cycle of pulp and paper EEM studies. IOCs are: directed into either an eutrophication-based investigation or a contaminant-based investigation (including metabolic disruption in fish). The framework is constructed with a progression of investigative levels designed to provide mole information on the causative factors. Each of these phases also represents a decision point for stakeholders to determine if sufficient information has been attained about the causal factor(s) and whether the IOC should be concluded. It is expected that the framework will evolve with a growing knowledge base of causal factors, as facilities enter into this phase of the EEM Program. [ABSTRACT FROM AUTHOR]

Abstract: Two experiments using rainbow trout (Oncorhynchus mykiss) were conducted to examine the combined effects of energy intake as manipulated by ration and pulp and paper mill effluent exposure over either one, or two consecutive reproductive cycles. This study demonstrated that the level of energy intake affected the full range of measured parameters from energy allocation to somatic growth and the gonadal development, steroid production and hematology. Increasing ration level expectedly increased growth, condition, liver and gonad size. Female trout in the higher ration treatments produced more follicles and had larger eggs, investing the same relative proportion of total energy into ovarian development. Sex steroid levels and hematological parameters were also positively influenced by increasing ration level in males and females. By far, the most dramatic impact of reduced ration on reproduction was to substantially reduce the frequency of sexually maturing fish. The effects of effluent exposure were not as marked as those linked to ration level and typically did not manifest unless fish were exposed through two consecutive reproductive cycles. The physiological effects of pulp and paper effluent exposure observed in these experiments were not consistent between the two experiments conducted herein, nor were they consistent with previously observed impacts in similar experiments with this effluent. Effluent exposure over one reproductive cycle did not impact physiological parameters in trout. However, when effluent exposure was maintained over two reproductive cycles, a new pattern of effluent response emerged including increased condition factor in both sexes, a decrease in the potential ability of the blood of females to transport oxygen, and increased sex steroids and reproductive investment in males. Effluent was also observed to cause reduced growth in male trout over two years. The effects of ration on gonad and liver size were far more obvious and consistent when a longer exposure was employed, thus, it appears to take more than one full year for energy intake changes to be reflected in those particular physiological endpoints. [Copyright &y& Elsevier]

The rapid urbanization and industrialization have caused a significant increase in environmental pollution, especially in air quality. This paper introduces an IoT-based environmental monitoring system to address these issues. Using state-of-the-art IoT technology, the system deploys sensors in key locations to continuously collect data on air quality indicators like Particulate Matter (PM), Carbon Monoxide (CO), and Ozone (O3). The collected data is wirelessly transmitted to a central server for processing and analysis. The system provides real-time and historical data through a user-friendly interface, enabling users to monitor current conditions, identify trends, and identify potential pollution sources. The key features include scalability, allowing for the addition of new sensors, and proactive decision-making through alerts when environmental parameters exceed predefined thresholds. This paper aims to empower communities with the knowledge needed to address and mitigate air pollution, creating healthier and more liveable urban environments in the face of rapid global urbanization. [ABSTRACT FROM AUTHOR]

This paper introduces an innovative IoT-enabled crop storage monitoring system designed to revolutionize the preservation and quality assurance of stored agricultural produce. Central to this system are IoT sensors strategically deployed within storage facilities. These sensors are tasked with the continuous tracking and monitoring of crucial environmental parameters, specifically temperature, humidity, and gas levels. Leveraging this real-time data, the system is engineered to promptly detect and respond to any deviations from the prescribed optimal storage conditions. The core strength of this system lies in its ability to generate instantaneous alerts upon detecting irregularities. These alerts serve as preemptive measures, effectively averting potential spoilage and curtailing post-harvest losses by enabling timely interventions and corrective actions. By harnessing IoT technology, this paper aims to create a proactive, automated, and responsive framework that ensures the integrity and safety of stored agricultural produce, ultimately contributing to enhanced food security and sustainability. [ABSTRACT FROM AUTHOR]

Preventive Conservation (PC) aims to minimize the risk of irreversible damage to cultural artifacts caused by environmental factors. Strategies for PC include implementing environmental recommendations and monitoring conditions. However, environmental monitoring alone is not enough, and predictive analysis is needed to assess the risk of damage. The collection "Preventive Conservation, Predictive Analysis and Environmental Monitoring" presents technological advances in studying material degradation and environmental monitoring. Papers cover topics such as paper degradation, wood degradation, canvas paintings, dyed textiles, sensor electronics, wireless communications, cloud computing, and machine learning. The collection provides valuable insights for the design of preventive conservation strategies. [Extracted from the article]

A fluorescence sensing system based on supramolecular assembly of a perylene probe (PDI-BTMA) has been constructed to rapidly and accurately quantify TNP via smartphone. [Display omitted] • Smartphone-assisted fluorescence sensor based PDI-BTMA probe was constructed for TNP. • Visual sensing of TNP was accomplished rapidly in aqueous media with LOD of 9 nM. • Optical responses of PDI-BTMA were caused by the formation of supramolecular complex. • The sensor can detect TNP quantitatively with sensitivity in environmental samples. 2,4,6-trinitrophenol (TNP) is an environmentally deleterious substance with high toxicity and explosibility. It is of great significance for environmental protection and public health to establish a rapidly on-site monitoring method for perilous TNP. Current methods for detecting TNP mainly rely on traditional laboratory analysis lacking rapid detection through intelligent modes. Herein, we construct a smartphone recognition based fluorescence sensing system via the supramolecular assembly of a perylene probe to quantify TNP. The sensing platform consists of a fluorescent probe based on quaternary ammonium functionalized perylene (PDI-BTMA), as the TNP-response recognition element, and smartphones as optical signals receptors bringing simpleness, celerity, and portability for TNP monitoring. The sensor reveals dual output signals of color and fluorescence in response to TNP. The results show that the optical responses of PDI-BTMA can be attributed to the formation of the supramolecular complex (PDI-BTMA/TNP) via non-covalent interactions including static electricity, hydrophobic interaction, charge transfer, and π-π stacking. It shows a wide linear range for TNP of 200–1200 nM with a detection limit of 9 nM. In addition, we successfully made portable PDI-BTMA fluorescence paper. The RGB value of fluorescence color was also collected by using the smartphone-assisted sensing platform, and the G/B channel values show a linear relationship with TNP concentration in 0.1–50 μM, with the lowest detection concentration of 48.4 nM. Additionally, it could be successfully utilized for quantitative TNP monitoring in environmental water and soil samples, which achieved a greater recovery rate in the range of 99–110%. This research integrating the PDI-BTMA probe with a smartphone firstly presents a new strategy for real-time and on-site monitoring of TNP in the environment. [ABSTRACT FROM AUTHOR]

The Canadian federal government instituted an environment effects monitoring (EEM) program for the pulp and paper industry to ensure the long-term integrity of fish populations below the discharge of mill effluents. The program is cyclical in nature (every three to four years) and one of the components of the program is an adult fish survey which monitors wild fish health in the receiving environments. Cycle 1 reports were submitted in April of 1996, and the report for the James Maclaren Inc. mill at Thurso, Quebec, suggested some responses were evident in fish downstream of the mill discharge. However, the receiving environment was subject to inputs from other potential sources or confounding factors such as farm runoff, storm sewers, municipal discharges and upstream paper mills. A review of other Cycle I studies also identified a number of problems encountered during the adult fish surveys. At this time, Maclaren researchers and Environment Canada set up a collaborative research project as part of their Cycle 2 studies at the Thurso site. Objectives of the study included a comparison of Cycle 2 results to their Cycle I studies, an assessment of the potential for the use of forage fish in the EEM program as well as an evaluation of reference site variability in the required EEM fish parameters. Collections in 1997 confirmed an increased male yellow perch liver size downstream of the discharge, but could not confirm reproductive alterations in exposed fish. It was possible to obtain all of the required EEM fish parameters from a small forage fish species such as the johnny darter, which may reduce the influence of fish mobility and other confounding factors on fish responses at some sites. Reference site variability was not a contributing factor in evaluating fish responses to effluent sources at this site. [ABSTRACT FROM AUTHOR]

Microfluidic paper-based analytical devices (microPADs) are an emerging platform for point-of-care assays with potential applications ranging from medical diagnostics to environmental monitoring. A standard approach for signal generation and amplification on microPADs is the use of enzymes and chromogenic substrates, which produce colored products and enable the qualitative and quantitative detection of analytes. Horseradish peroxidase (HRP) is one of the most commonly used enzymes for this application. While a wide variety of chromogenic substrates and substrate solutions are available for HRP, these were all originally developed and optimized for other platforms and have not been systematically compared on microPADs. In this work, 33 chromogenic substrate solutions for HRP containing one of six different substrate molecules were evaluated in a standardized colorimetric assay and compared on the basis of limit of detection (LOD), lower limit of quantitation (LLOQ), upper limit of quantitation (ULOQ), sensitivity, dynamic range, stability, and cost. While the substrates tetramethylbenzidine (TMB) and o-phenylenediamine (OPD) were found to achieve the best overall analytical performance, each substrate had characteristics that may make them appealing for specific applications. The results of this work will facilitate the selection of substrate molecules and the formulation of substrate solutions for future colorimetric paper-based assays involving HRP. • Six chromogenic substrates for HRP in 33 different formulations were evaluated on microPADs. • TMB and OPD provided the best overall LOD, LLOQ and sensitivity. • ABTS provided the best ULOQ and dynamic range. • Results will facilitate the selection of suitable substrates for future applications. [ABSTRACT FROM AUTHOR]

Volatile organic compound (VOC) detection is critical for controlling industrial and commercial emissions, environmental monitoring, and public health. Simple, portable, rapid and low-cost VOC sensing platforms offer the benefits of on-site and real-time monitoring anytime and anywhere. The best and most practically useful approaches to monitoring would include equipment-free and power-free detection by the naked eye. In this work, we created a novel, paper-based cantilever sensor array that allows simple and rapid naked-eye VOC detection without the need for power, electronics or readout interface/equipment. This simple VOC detection method was achieved using (i) low-cost paper materials as a substrate and (ii) swellable thin polymers adhered to the paper. Upon exposure to VOCs, the polymer swelling adhered to the paper-based cantilever, inducing mechanical deflection that generated a distinctive composite pattern of the deflection angles for a specific VOC. The angle is directly measured by the naked eye on a 3-D protractor printed on a paper facing the cantilevers. The generated angle patterns are subjected to statistical algorithms (linear discriminant analysis (LDA)) to classify each VOC sample and selectively detect a VOC. We classified four VOC samples with 100% accuracy using LDA. Graphical abstractfx1Highlights· We created a novel, paper-based cantilever gas sensor array. · It allowed simple and rapid naked-eye VOC detection. · Upon exposure to VOCs, the mechanical deflection of the cantilevers was monitored. [ABSTRACT FROM AUTHOR]

This article describes a method for fabricating 3D microfluidic devices by stacking layers of patterned paper and double-sided adhesive tape. Paper-based 3D microfluidic devices have capabilities in microfluidics that are difficult to achieve using conventional open-channel microsystems made from glass or polymers. In particular, 3D paper-based devices wick fluids and distribute microliter volumes of samples from single inlet points into arrays of detection zones (with numbers up to thousands). This capability makes it possible to carry out a range of new analytical protocols simply and inexpensively (all on a piece of paper) without external pumps. We demonstrate a prototype 3D device that tests 4 different samples for up to 4 different analytes and displays the results of the assays in a side-by-side configuration for easy comparison. Three-dimensional paper-based microfluidic devices are especially appropriate for use in distributed healthcare in the developing world and in environmental monitoring and water analysis. [ABSTRACT FROM AUTHOR]

The article focuses on environmental paper calculators which are increasingly being used by marketers of all types who are looking to boost the sustainability image of their company. It is reported that online environmental paper calculators compares the environmental impact papers in terms of wood use, energy, greenhouse gases, waste water, solid waste, and other components to a baseline of paper with no recycled content.

A study was conducted in a marine inlet to assess the effects of untreated discharges from a pulp and paper mill, a municipality, and industries in western Newfoundland on winter flounder ( Pleuronectes americanus), a fish species shown previously to be sensitive to environmental contaminants in sediment. The fish were captured by SCUBA divers about 2 km down-current from the mill discharging effluent containing resin acids, and at three reference sites 2 to 11 km away near the opposite shore, each spring in five consecutive years and the fish were necropsied on site. A total of 360 and 339 flounder were examined near the mill and references sites, respectively. Several bioindicators were used to assess fish health including parasites. More fish exhibiting external and microscopic lesions in several tissues, lower condition factors, elevated hepatosomatic index, and delayed reproductive development were observed in samples taken near the paper mill than at the reference sites. A higher prevalence of an ectoparasite, Cryptocotyle lingua, but a significantly lower mean abundance of three metazoans infecting the digestive tract was noted in fish near the mill than in the reference samples. These results, comprising abnormal fish size distribution, low body condition factor, external and internal lesions, enlarged liver, delayed gonadal development, and changes in parasitism, were stress-related, indicative of impaired health, and associated primarily with untreated discharges from the pulp and paper mill. This integrated and multidisciplinary study also provides further evidence on the use of fish parasites as a valid and an additional bioindicator in programs monitoring environmental contaminants. [ABSTRACT FROM AUTHOR]

Research on environmental reporting within individual sectors and industries is limited. Generic studies have typically focused on the reporting practices of the world's largest corporates. Some industries and sectors are under-represented within these studies, limiting the potential for industry- or sector-specific analysis. Forest and paper is one industry frequently under-represented. This study examines environmental reporting amongst the top 100 forest and paper companies. The scale of environmental report publication is investigated, and the breadth and depth of reporting on the key industry issues of forest management and fibre procurement examined. The results show reporting is more prevalent amongst larger corporates but marked regional variations are evident. Most noticeably, Scandinavian companies are reporting more extensively, both in terms of the number of levels at which they report and the depth of information included on forest management and fibre procurement. Reasons for the marked regional variations in reporting are considered and markets for forest products and preferences within those markets for specific certification schemes identified as potential influencing factors. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment. [ABSTRACT FROM AUTHOR]

Since 2007, the world of microfluidics saw an emergence of a new era of low cost, simple, quick fabrication, abundantly available, and environmentally friendly microfluidic paper-based analytical devices (μPADs) capable of clinical diagnostics, food quality control as well as environmental monitoring. Although many fabrication techniques have evolved as a result of its broad application spectrum and ease of use, the technology has still barely scratched the surface of its potential in terms of its underlying fundamental principle, i.e., fluid flow analysis. In this study, we report the comparison of flow profile attained by using two of the most promising techniques of photolithography and wax printing from a hydrodynamic point of view. A modified protocol for synthesizing an epoxy based negative photoresist (SU-8) channel and wax-based channel was created by optimizing a few process parameters of our equipment. Water and oil (oleic acid) are selected as the hydrophilic and hydrophobic fluids, respectively, and their flow was analyzed in straight channels using a paper device. A new approach to vary the flow velocity is described in detail involving cylindrical dots as the resistance inside the paper channel. Observing the length-time curve for the two fluids, it becomes evident that both follow the Lucas–Washburn equation if the width of the channel is large enough. Various configurations of dots indicate that different longitudinal flow velocity implying its application in simultaneous addition of chemicals without the need to change the channel width or length. [ABSTRACT FROM AUTHOR]

Primary aromatic amines (PAAs) are a class of hazardous substances where many compounds are classified as carcinogen, mutagen, and reproduction toxin (CMR). PAAs can be taken up by dermal exposure. In the polyurethane industry, a valid and trustworthy method for the quantification of PAAs in the presence of isocyanates that could interfere is of great interest, especially on workplaces where a regular contact to PAAs cannot be excluded. The aim of this work is the development, validation, and verification of a novel sampling device to quantify selectively the PAA load on work surfaces. We describe the synthesis of Cell-ßALA-PEMSA analytical papers and their characterization by infrared spectroscopy and thermogravimetric analysis. The recovery of TDA and MDA spiked on these filters is satisfactory. An excellent selectivity of Cell-ßALA-PEMSA papers towards PAAs in the presence of isocyanates of almost 100% was found by wipe tests of amine/isocyanate contaminated surfaces. First positive field tests were achieved at certain areas in a Polyurethane Technical Application Department where surface contamination with PAAs was expected, and the Cell-ßALA-PEMSA analytical papers were superior to an established method of surface sampling. However, recovery of these amines from surfaces shows a large variability, and more work is required to address influencing surface properties. [ABSTRACT FROM AUTHOR]

Nucleic acid testing (NAT) has been widely used for disease diagnosis, food safety control and environmental monitoring. At present, NAT mainly involves nucleic acid extraction, amplification and detection steps that heavily rely on large equipment and skilled workers, making the test expensive, time-consuming, and thus less suitable for point-of-care (POC) applications. With advances in paper-based microfluidic technologies, various integrated paper-based devices have recently been developed for NAT, which however require off-chip reagent storage, complex operation steps and equipment-dependent nucleic acid amplification, restricting their use for POC testing. To overcome these challenges, we demonstrate a fully disposable and integrated paper-based sample-in-answer-out device for NAT by integrating nucleic acid extraction, helicase-dependent isothermal amplification and lateral flow assay detection into one paper device. This simple device allows on-chip dried reagent storage and equipment-free nucleic acid amplification with simple operation steps, which could be performed by untrained users in remote settings. The proposed device consists of a sponge-based reservoir and a paper-based valve for nucleic acid extraction, an integrated battery, a PTC ultrathin heater, temperature control switch and on-chip dried enzyme mix storage for isothermal amplification, and a lateral flow test strip for naked-eye detection. It can sensitively detect Salmonella typhimurium, as a model target, with a detection limit of as low as 102 CFU ml−1 in wastewater and egg, and 103 CFU ml−1 in milk and juice in about an hour. This fully disposable and integrated paper-based device has great potential for future POC applications in resource-limited settings. [ABSTRACT FROM AUTHOR]

Paper microfluidics is a rapidly growing subfield of microfluidics in which paper-like porous materials are used to create analytical devices. There is a need for higher performance field-use tests for many application domains including human disease diagnosis, environmental monitoring, and veterinary medicine. A key factor in creating high performance paper-based devices is the ability to manipulate fluid flow within the devices. This critical review is focused on the progress that has been made in (i) the development of fluid flow control tools and (ii) the integration of those tools into paper microfluidic devices. Further, we strive to be comprehensive in our presentation and provide historical context through discussion and performance comparisons, when possible, of both relevant earlier work and recent work. Finally, we discuss the major areas of focus for fluid flow methods development to advance the potential of paper microfluidics for high-performance field applications. [ABSTRACT FROM AUTHOR]

Paper-based analytical devices are lightweight, inexpensively produced, effective, and easily disposable; allowing for their suitable implementation in resource-limited areas. They allow effective handling of quantitative analysis in a diverse range of areas, from standard healthcare and environmental monitoring to water quality monitoring. Nonetheless, such devices often require an energy source for their complex assays or readings, preventing their effective use. Most commonly, conventional batteries are integrated into the device to serve as an energy source. However, considering its non-environmentally friendly approach to energy generation and its difficulty of being effectively disposed, a search for a new power source has begun. In light of the newly found potential of cellulose-based entities in the energy field, attention has been drawn towards a supposedly unlikely material: paper. Considering the potentials of such technology, this manuscript aims to describe the benefits of current and future technologies of paper-based devices in the energy sector. Here, we discuss the role of paper as a main platform or part of energy storage and conversion devices such as fuel cells, lithium-ion batteries, and alkaline batteries thoroughly. [ABSTRACT FROM AUTHOR]

In today's world, a significant amount of global energy is used in buildings. Unfortunately, a lot of this energy is wasted, because electrical appliances are not used properly or efficiently. One way to reduce this waste is by detecting, learning, and predicting when people are present in buildings. To do this, buildings need to become "smart" and "cognitive" and use modern technologies to sense when and how people are occupying the buildings. By leveraging this information, buildings can make smart decisions based on recently developed methods. In this paper, we provide a comprehensive overview of recent advancements in Internet of Things (IoT) technologies that have been designed and used for the monitoring of indoor environmental conditions within buildings. Using these technologies is crucial to gathering data about the indoor environment and determining the number and presence of occupants. Furthermore, this paper critically examines both the strengths and limitations of each technology in predicting occupant behavior. In addition, it explores different methods for processing these data and making future occupancy predictions. Moreover, we highlight some challenges, such as determining the optimal number and location of sensors and radars, and provide a detailed explanation and insights into these challenges. Furthermore, the paper explores possible future directions, including the security of occupants' data and the promotion of energy-efficient practices such as localizing occupants and monitoring their activities within a building. With respect to other survey works on similar topics, our work aims to both cover recent sensory approaches and review methods used in the literature for estimating occupancy. [ABSTRACT FROM AUTHOR]

Paper-based analytical devices (PADs), including lateral flow assays (LFAs), dipstick assays and microfluidic PADs (μPADs), have a great impact on the healthcare realm and environmental monitoring. This is especially evident in developing countries because PADs-based point-of-care testing (POCT) enables to rapidly determine various (bio)chemical analytes in a miniaturized, cost-effective and user-friendly manner. Low sensitivity and poor specificity are the main bottlenecks associated with PADs, which limit the entry of PADs into the real-life applications. The application of nanomaterials in PADs is showing great improvement in their detection performance in terms of sensitivity, selectivity and accuracy since the nanomaterials have unique physicochemical properties. In this review, the research progress on the nanomaterial-based PADs is summarized by highlighting representative recent publications. We mainly focus on the detection principles, the sensing mechanisms of how they work and applications in disease diagnosis, environmental monitoring and food safety management. In addition, the limitations and challenges associated with the development of nanomaterial-based PADs are discussed, and further directions in this research field are proposed. [ABSTRACT FROM AUTHOR]

This paper describes the development of a new system for amperometric determination of phenolic compounds, and its application for monitoring these compounds in paper mill effluent. The method was based on a flow system, a dialysis sampler, and a laccase-based biosensor. The performance of this system was investigated with respect to pH, ionic strength, working potential, and flow-rate dependence. The biosensor showed an excellent long-term stability allowing measurements for over than 3 months. The sensitivity of laccase-based biosensor was tested for phenol, p-chlorophenol, guaiacol and chloroguaiacol; the detector presented selective measurements of micromolar concentration of these compounds. The integration of a dialysis membrane sampling in the system protected the biosensor surface from fouling and gave independence of sample conditions that commonly influence the biosensor performance. These favorable characteristics allowed its application for direct measurements in complex media with no sample pretreatment. This ability was confirmed employing this system in a continuous analysis of phenolic compounds during the remediation of paper mill effluent by ozonization process. [Copyright &y& Elsevier]

The field of paper-based microfluidics has experienced rapid growth over the past decade. Microfluidic paper-based analytical devices (μPADs), originally developed for point-of-care medical diagnostics in resource-limited settings, are now being applied in new areas, such as environmental analyses. Low-cost paper sensors show great promise for on-site environmental analysis; the theme of ongoing research complements existing instrumental techniques by providing high spatial and temporal resolution for environmental monitoring. This review highlights recent applications of μPADs for environmental analysis along with technical advances that may enable μPADs to be more widely implemented in field testing. [ABSTRACT FROM AUTHOR]

• This manuscript reviews the history and new developments of ePADs from 2016 to 2021. • This review focuses on construction and representative applications of ePADs. • The limiting factors and future development of ePADs have been discussed. Integration of electrochemical detection methods into paper-based analytical devices (PADs) provides a powerful tool for the area of point-of-care testing (POCT) because the electrochemical PADs (termed as ePADs) enable to rapidly determine a broad spectrum of analytes from ions to living cells in a miniaturized, cost-effective and user-friendly manner. Recently, nanomaterials and their composites were extensively introduced in ePADs for improvement of their detection performance. This review attempts to provide a comprehensive information on the ePADs including a general aspect of ePADs and recent development of ePADs by highlighting selected publication. We mainly focus on the fabrication of ePADs, enhancement strategies of nanomaterials and potential applications of ePADs in the fields of environmental monitoring, food safety management and disease diagnosis. Based on the limitations and challenges associated with the development of ePADs, the future perspectives of this research field are proposed. [ABSTRACT FROM AUTHOR]

Paper is a widely used support for use in devices for point-of-care testing (POCT) in clinical diagnosis, food safety monitoring and environmental pollution. Paper is inexpensive, biocompatible, biodegradable and allows a sample fluid to flow by capillary force. Numerous method have been developed recently for chemical modification of papers in order to introduce different functionalities. This review (with 148 refs.) summarizes the recent progress in paper-based POCT devices. The introduction summarizes the state of the art of paper-based POCT devices and the physicochemical properties of existing unmodified materials (including cellulose, cellulose-based composites, cotton fibers, glass fibers, nitrocellulose, thread). Methods for paper modification for sample pretreatment are summarized next, with subsections on sample storage and collection, sample separation, nucleic acid extraction and sample preconcentration. Another main section covers approaches for paper modification for improving POCTs, with subsections on assays for proteins, nucleic acids, drugs, ion and organic molecules. The advantages and disadvantages of these approaches are compared. Several tables are presented that summarize the various modification techniques. A concluding section summarizes the current status, addresses challenges and gives an outlook on future perspectives of POCTs. [ABSTRACT FROM AUTHOR]

A low cost, microfluidic paper electrochemical device (μPED) was fabricated using screen printing of electrodes and heat transfer of patterned wax paper onto filter paper. The μPED features films of a light-emitting ruthenium metallopolymer, microsomal metabolic enzymes, and DNA to detect potential genotoxic pollutant activity in environmental samples. Unlike conventional analytical methods that detect specific pollutant compounds, the μPED was designed to rapidly measure the presence of genotoxic equivalents in environmental samples with the signal related to benzo[a]pyrene (B[a]P) as a reference standard. The analytical end point is the detection of DNA damage from metabolites produced in the device using an electrochemiluminescence output measured with a charge-coupled device (CCD) camera. Proof-of-concept of this measurement was established for smoke, water, and food samples. The μPED provides a rapid screening tool for on-site environmental monitoring that specifically monitors the genotoxic reactivity of metabolites of toxic compounds present in the samples. [ABSTRACT FROM AUTHOR]

The purpose of this inquiry is to identify how environmental indicators and environmental technology in the science/policy boundary alternately facilitate and encumber international environmental negotiations. In a case involving a dispute between Sweden and Finland over one another’s contribution to the organochlorine pollution load to the Baltic Sea, indicators of environmental risk, including measures of allegedly toxic concentrations of organochlorines in Swedish and Finnish chemical pulp wastewater, did not bring the two sides closer to a settlement. Also, ironically, advances in technological solutions to the problem were unhelpful to the negotiation. For many months, the disputants failed to acknowledge that deliberations were slowed down by the parties’ pride and confidence in their respective national scientific, technological, and regulatory institutions. In recent years, the problems caused by organochlorine emissions from Swedish and Finnish pulp mills have been all but solved—a comparatively rare transboundary environmental “success story.” With the tackling of the problem, the competition between Sweden and Finland’s preferred engineering solutions has dramatically faded. [ABSTRACT FROM AUTHOR]

Lateral flow assays (LFAs) hold great promise for point-of-care testing, especially in resource-poor settings. However, the poor sensitivity of LFAs limits their widespread applications. To address this, we developed a novel device by integrating dialysis-based concentration method into LFAs. The device successfully achieved 10-fold signal enhancement in Human Immunodeficiency Virus (HIV) nucleic acid detection with a detection limit of 0.1 nM and 4-fold signal enhancement in myoglobin (MYO) detection with a detection limit of 1.56 ng/mL in less than 25 min. This simple, low-cost and portable integrated device holds great potential for highly sensitive detection of various target analytes for medical diagnostics, food safety analysis and environmental monitoring. [ABSTRACT FROM AUTHOR]

[Display omitted] • A portable nanocluster-modified paper analytical device integrated with a syringe for highly sensitive Hg2+ detection. • The CMC-EDC/NHS method attaches AuNCs to the substrate, preventing the AuNCs from leaching. • This platform accumulates the signal of Hg2+ by flowing with increased solution volume. • The platform can complete the detection of Hg2+ ions within 30 min, with a detection limit as low as 1.2 nM. To minimize the need for complex testing procedures, sophisticated instrumentation, and electricity for on-site testing, we demonstrate a simple and portable gold nanocluster (AuNC)-modified paper analytical device integrated with syringe-driven fluid flow to enable highly sensitive mercury ion (Hg2+) detection for environmental monitoring. The device is composed of a paper substrate modified with fluorescent AuNCs (AuNC-paper), which is held within a reusable cartridge connected to a syringe, thus allowing users to flow a large volume of the sample solution through the paper test for greater accumulation of the analyte signal. The metallophilic d10-d10 interaction of Hg2+ with Au+ on the surface of the AuNC-paper induces fluorescence quenching, which can be monitored using a smartphone. Importantly, the red-emitting AuNCs avoid interference with the background fluorescence of the paper substrate. Additionally, the AuNCs are strongly-attached to the paper substrate via carbodiimide coupling, which helps prevent the AuNCs from leaching and enables a large amount of solution to interact with the test (up to 2.5 mL) to increase the amount of the target ions that react with the AuNC-paper. As a result, without the need for preconcentrating the test solution, this paper device can provide the highly sensitive detection of Hg2+ ions, including a 26-fold higher sensitivity than the AuNC-modified test paper without a fluidic cartridge, at a low level of down to nM. The paper platform can complete the detection of Hg2+ ions within 30 min, with a detection limit as low as 1.2 nM, which is less than the United States Environmental Protection Agency's regulatory limit for drinking water. This highly sensitive, selective, portable, and easy-to-operate platform may be valuable for on-site mercury pollution monitoring in resource-constrained settings. [ABSTRACT FROM AUTHOR]

A capability that is key to increasing the performance of paper microfluidic devices is control of fluid transport in the devices. We present dissolvable bridges as a novel method of manipulating fluid volumes within paper-based devices. We demonstrate and characterize the operation of the bridges, including tunability of the volumes passed from 10 μL to 80 μL, using parameters such as geometry and composition. We further demonstrate the utility of dissolvable bridges in the important context of automated delivery of different volumes of a fluid from a common source to multiple locations in a device for simple device loading and activation. [ABSTRACT FROM AUTHOR]

Per- and polyfiuoroalkyl substances (PFAS) on paper packaging resist water and oil to effectively contain food and beverages. However, previous studies have established correlations between PFAS and several diseases including COVID-19, cancers, and obesity. The goal of this collaborative research between the Philippines and Singapore is to set a baseline for PFAS levels in local packaging with the intended outcome of further increasing awareness on these contaminants in Southeast Asia, providing a starting point for migration experiments and risk assessments on PFAS in commercially-available food contact materials and articles, and initiating policy developments on these substances in the Philippines. In this study, 15 different types of PFAS were analyzed in selected paper packaging used by major quick service restaurants (QSRs) in Metro Manila. Using liquid chromatography-mass spectrometry (LC-MS), PFAS was detected in 100% of the samples with a total PFAS concentration range of 8.20-97.7 ng PFAS/100 cm². The highest amount of PFAS compound measured across all samples was PF-3,7-DMOA (89.8 ng/100 cm²). PFAS compounds regulated in European packaging such as PFHpA, PFOA, PFNA and PFDA were also detected in all samples but at trace levels. Paper wrappers for rice and small burgers were found to have the highest total PFAS of 97.7 ng PFAS/100 cm². This value translates to approximately 65.1 ng F/100 cm² which is way below 10,000 ng F/100 cm², the currently existing limit for PFAS in packaging set by the Danish Ministry of Environment and Food. While each packaging may be deemed safe compared to regulation, the compounded effects brought by use of multiple packaging, and high frequency and long-term exposures require further investigation. [ABSTRACT FROM AUTHOR]

Abstract: The preparation and evaluation of a simple paper-based device for the determination of reactive phosphate in natural and soil waters based on the formation of phosphomolybdenum blue is reported. Hydrophilic reagent zones were defined by printing filter paper with a hydrophobic paper-sizing agent using an inkjet printer. The molybdate/potassium antimony(III)-tartrate reagent and ascorbic acid reductant merged together from adjacent hydrophilic zones after spotting the liquid sample onto the paper. The colour intensity of the phosphoantimonylmolybdenum blue complex produced was measured using a flat bed scanner. Under optimal conditions, the paper-based device is characterised by a working range of 0.2–10mgL−1 P, limits of detection and quantitation of 0.05 and 0.16mgL−1 P, respectively, and repeatability of less than 2% RSD at 1 and 5mgL−1 P (n=10 and 8). There was no significant difference between the results obtained using the paper-based device and reference methods (t=0.0135, P (T≤t) two-tail=0.9892, df=38). In its optimum form, the paper-based device was stable for up to 15 day under ambient conditions, and up to 122day when stored at ≤−20°C. The small dimensions, minimal reagent consumption, low cost (a few cents), ease of operation and favourable analytical performance make the proposed paper-based device attractive for on-site environmental monitoring and analysis. [Copyright &y& Elsevier]

• Stationery, Pencils, Papers for fabricating paper-based analytical devices. • Hydrophobic barriers, Cutting and Electrode fabrication. • Robust and Easy-to-use methodology. • Deployable to resource limited settings and scalable for point-of-care diagnostics and detection. Paper-based devices for an analytical application have gained great interest among researchers due to their portability, versatility and facile interpretation. The popularity of these analytical devices is supplemented by their myriad of applications, in point-of-care health systems, environmental monitoring and food safety. However, relatively sophisticated manufacturing techniques used to create complex multiplexed systems, pose barrier between the widespread adoption of the such methods in low-cost settings. Recently, researchers have taken significant efforts towards the development of paper-based analytical devices with more emphasis on novel fabrication approaches costing <1$. Such an approach was achieved by implementing Do-It-Yourself (DIY) path by employing readily available stationaries for fabrication. Here in this review, we categorise such Do-It-Yourself (DIY) approaches and explore their further developments and challenges. Moreover, we discuss the use of various low cost or off-the-shelf equipments for the fabrication of (i) hydrophobic barriers on plain paper (ii) electrodes in detection devices, and (iii) devices porting old detection techniques on to more DIY friendly housings. Additionally, this paper also explores amalgamation of multiple DIY fabrication methods, emerging trends and prospects in the past five years. [ABSTRACT FROM AUTHOR]

The development of low-cost analytical devices for on-site water quality monitoring is a critical need, especially for developing countries and remote communities in developed countries with limited resources. Microbial electrochemical cell-based (MXC) biosensors have been quite promising for quantitative and semi-quantitative (often qualitative) measurements of various water quality parameters due to their low cost and simplicity compared to traditional analytical methods. However, conventional MXC biosensors often encounter challenges, such as the slow establishment of biofilms, low sensitivity, and poor recoverability, making them unable to be applied for practical cases. In response, MXC biosensors assembled with paper-based materials demonstrated tremendous potentials to enhance sensitivity and field applicability. Furthermore, the paper-based platforms offer many prominent features, including autonomous liquid transport, rapid bacterial adhesion, lowered resistance, low fabrication cost (<$1 in USD), and eco-friendliness. Therefore, this review aims to summarize the current trend and applications of paper-based MXC biosensors, along with critical discussions on their field applicability. Moreover, future advancements of paper-based MXC biosensors, such as developing a novel paper-based biobatteries, increasing the system performance using an unique biocatalyst, such as yeast, and integrating the biosensor system with other advanced tools, such as machine learning and 3D printing, are highlighted. [Display omitted] • Studies related to paper-based MXC biosensors are summarized and reviewed. • Benefits of using paper-based platforms over traditional materials are listed. • Current applications and challenges of paper-based MXC biosensors are provided. • Field applicability of paper-based MXC biosensors is highlighted. • Opportunities to integrate 3D printing and machine learning are discussed. [ABSTRACT FROM AUTHOR]

Lab-on-paper technologies, also known as paper-based analytical devices (PADs), have received increasing attention in the last years, and nowadays, their use has spread to virtually every application area, i.e., medical diagnostic, food safety, environmental monitoring, etc. Advantages inherent to on-field detection, which include avoiding sampling, sample preparation and conventional instrumentation in central labs, are undoubtedly driving many developments in this area. Heavy metals represent an important group of environmental pollutants that require strict controls due to the threat they pose to ecosystems and human health. In this overview, the development of PADs for Hg monitoring, which is considered the most toxic metal in the environment, is addressed. The main emphasis is placed on recognition elements (i.e., organic chromophores/fluorophores, plasmonic nanoparticles, inorganic quantum dots, carbon quantum dots, metal nanoclusters, etc.) employed to provide suitable selectivity and sensitivity. The performance of both microfluidic paper-based analytical devices and paper-based sensors using signal readout by colorimetry and luminescence will be discussed. [ABSTRACT FROM AUTHOR]

This paper provides a thorough comparison of sophisticated biosensors and conventional sensors, explaining the underlying technologies, working theories, and performance measures of each in analytical detection applications. Through analyzing the essential distinctions and parallels between them, this paper brings to light the unique benefits and constraints of every technology with respect to sensitivity, specificity, reaction speed, and mobility. This paper also examines the various uses of sensors and biosensors in healthcare, environmental monitoring, and industrial processes, offering insights into the special qualities and possible collaborations of these platforms. Looking ahead, this paper explores new developments in data analytics, microfluidics, and nanotechnology that will lead to next-generation sensing technologies with improved analytical capabilities and wider practical uses. [ABSTRACT FROM AUTHOR]

Restoration ecology is a deepening and diversifying field with current research incorporating multiple disciplines and infusing long-standing ideas with fresh perspectives. We present a list of 10 recent pivotal papers exemplifying new directions in ecological restoration that were selected by students in a cross-disciplinary graduate seminar at the University of California, Berkeley. We highlight research that applies ecological theory to improve restoration practice in the context of global change (e.g. climate modeling, evaluation of novel ecosystems) and discuss remaining knowledge gaps. We also discuss papers that recognize the social context of restoration and the coupled nature of social and ecological systems, ranging from the incorporation of cultural values and Traditional Ecological Knowledge into restoration, to the consideration of the broader impacts of markets on restoration practices. In addition, we include perspectives that focus on improving communication between social and natural scientists as well as between scientists and practitioners, developing effective ecological monitoring, and applying more integrated, whole-landscape approaches to restoration. We conclude with insights on recurrent themes in the papers regarding planning restoration in human-modified landscapes, application of ecological theory, improvements to restoration practice, and the social contexts of restoration. We share lessons from our cross-disciplinary endeavor, and invite further discussion on the future directions of restoration ecology through contributions to our seminar blog site . [ABSTRACT FROM AUTHOR]

The fast detection of trace amounts of hazardous contaminations can prevent serious damage to the environment. Paper-based sensors offer a new perspective on the world of analytical methods, overcoming previous limitations by fabricating a simple device with valuable benefits such as flexibility, biocompatibility, disposability, biodegradability, easy operation, large surface-to-volume ratio, and cost-effectiveness. Depending on the performance type, the device can be used to analyze the analyte in the liquid or vapor phase. For liquid samples, various structures (including a dipstick, as well as microfluidic and lateral flow) have been constructed. Paper-based 3D sensors are prepared by gluing and folding different layers of a piece of paper, being more user-friendly, due to the combination of several preparation methods, the integration of different sensor elements, and the connection between two methods of detection in a small set. Paper sensors can be used in chromatographic, electrochemical, and colorimetric processes, depending on the type of transducer. Additionally, in recent years, the applicability of these sensors has been investigated in various applications, such as food and water quality, environmental monitoring, disease diagnosis, and medical sciences. Here, we review the development (from 2010 to 2021) of paper methods in the field of the detection and determination of toxic substances. [ABSTRACT FROM AUTHOR]

Paper mill effluents may contain polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) that are normally generated due to chlorinated bleaching of pulp and paper. We used the semipermeable membrane device (SPMD) to monitor PCDD/F levels upstream and downstream of a paper mill on the Androscoggin River, in Jay (ME). Following the 36 day deployment, SPMD dialysis and cleanup, the samples were analyzed by HRGC/HRMS. Total concentrations of PCDD/Fs in SPMDs (sum of all tetra-through octachlorinated congeners) ranged from 4.71pgg−1 to 26.26pgg−1. Five out of the targeted 17 toxic congeners were detected, including: 2,3,7,8-TCDF; 1,2,3,7,8-PeCDF; 2,3,4,7,8-PeCDF; 1,2,3,4,6,7,8-HpCDD and OCDD. Permeability reference compounds (PRCs) were used for in situ calibration of the SPMD sampling rate (R s). In all sites, water concentrations were the highest for OCDD (0.081–0.103pgl−1), and the lowest for 1,2,3,7,8-PeCDF (0.005–0.009pgl−1). There was not a consistent pattern of upstream–downstream gradient in the PCDD/F levels. This suggested that processes other than the mill in Jay (multiple sources, river dynamics) governed the flux of PCDD/Fs in the sampling locations. The SPMD results were validated by comparison to other studies on the Androscoggin River and elsewhere, confirming the potential of the device as a useful monitoring technique for PCDD/Fs in large river systems. [Copyright &y& Elsevier]

In this paper, a bifunctional tri-site fluorescent probe was designed for the first time not only for visualization and quantitative analysis of sensing H 2 S in wastewater by coupling paper strip and smartphone (Color recognizer, Xiyi Technology) but also for sensitively monitoring GSH in living cells, which relied on different emission channels and the pH of solutions. The recognition properties of GH towards H 2 S/GSH were satisfactorily demonstrated through fluorescence, UV–vis, 1H NMR and DFT calculations. More importantly, integrated with the paper strip, portable smartphone-sensing platform with a color recognizer app would accomplish cost-effective and rapid assays for colorimetric water quality testing, which displayed huge application potential in fields of environmental monitoring. ga1 • GH could simultaneously detect H 2 S in wastewater and GSH in living cells. • The mechanism of GH towards H 2 S/GSH was demonstrated through fluorescence, UV–vis, 1H NMR and DFT calculations. • Portable fluorescent paper strips are widely used in field inspections. • Fluorescent paper strips of GH integrated with smartphone can realize quantitative monitor of H 2 S in wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Distinctive hydrophilic-hydrophobic SERS substrates have been fabricated utilizing ordinary papers loaded with Ag nanowires. • Remarkable SERS activity with an enhancement factor (EF) up to 2.63 × 106 was achieved. • An in-situ detection of trace furazolidone on fish under the interference of malachite green was realized. As a typical membrane matrix with attractive flexibility, paper has exhibited great feasibility to serve as surface-enhanced Raman scattering (SERS) substrate in the environmental monitoring and surveillance. In this research, we have designed and fabricated a distinctive hydrophilic-hydrophobic SERS substrate utilizing several ordinary papers loaded with Ag nanowires (Ag NWs). Remarkable SERS activities with an enhancement factor (EF) up to 2.63 × 106 was successfully achieved in the assembly Ag NWs with the optimal amount of nanotips and overlaps. The hydrophilic-hydrophobic strategy could contribute to anchoring microdroplets and thus enrich analytes to improve the homogeneity of substrate with a low relative standard deviation of 10.6%. Furthermore, the sophisticated SERS substrate was also applied in the in-situ detection of trace furazolidone on fish under the interference of malachite green and the reliable recovery rates were demonstrated as well. [ABSTRACT FROM AUTHOR]

• Metabolic biomarker profiles were used for the prediction of clinical diagnoses. • k-NN classifiers were fitted to demonstrate the reliability of µPADs derived data. • Predictors were associated with glucose, lactate, and uric acid concentrations. • Metabolic disorders were suitably predicted with 95.0% overall accuracy. • The modeling addressed here proved that the µPADs could be applied in telemedicine. The development of microfluidic devices for point-of-care (POC) testing has been widely applied for food quality control, environmental monitoring, and clinical diagnoses. Regarding the latter, microfluidic paper-based analytical devices (µPADs) have a great potential in developing portable and disposable platforms for fast disease-relevant biomarker detection in remote areas. In this work, k-nearest neighbors (k-NN) classifiers were applied to demonstrate the reliability of using chemical data obtained from µPADs for diagnosis of diseases like diabetes mellitus and hyperuricemia. Predictors based on glucose, lactate, and uric acid biomarkers were evaluated to reach this goal. Healthy adults were differentiated from the diagnosed patients with a perfect success rate. Metabolic disorders were suitably predicted with 95.0% overall accuracy. This model also showed sensitivities and specificities in the ranges 75–100% and 93–100%, respectively, indicating that the classification protocol is robust. The k-NN modeling proved the potential of the µPADs to be applied in telemedicine for reliable off-site diagnoses. [ABSTRACT FROM AUTHOR]

In this paper, the design and the manufacture of an inkjet printed resistive type humidity sensor on paper are reported. After having been exposed to humidity above a given threshold level, the resistance of the sensor decreases substantially and remains at that level even when the humidity is reduced. It is possible to deduce the humidity level by monitoring the resistance. The main benefit of the printed sensor presented in this case is in relation to its very low production costs. It has also been shown that both the ink type and this paper combination used prove to be crucial in order to obtain the desired sensor effect. More research is required in order to fully understand the humidity sintering effect on the nano particle ink and the role of the substrate. However, the observed effect can be put to use in printed humidity sensors which possess a memory function. The sensor can be used in various applications for environmental monitoring, for example, in situations where a large number of inexpensive and disposable humidity sensors are required which are able to detect whether they have been subjected to high humidity. This could be the checking of transportation conditions of goods or monitoring humidity within buildings. [ABSTRACT FROM PUBLISHER]

The Canadian environmental effects monitoring (EEM) program is a regulated, cyclical, industry-funded program designed to determine whether receiving water impacts exist when a mill is in compliance with its discharge limits. The results from three cycles of the fish monitoring program (1992 to 2004) are available from over 200 surveys of fish compared between sites located upstream and downstream of pulp and paper mill effluent outfalls. Previous meta-analyses have shown a national average response pattern across cycles characterized by an increase in endpoints measuring energy storage and growth and a decrease in a reproductive endpoint, consistent with a response of nutrient enrichment in combination with some form of metabolic disruption. Although the national average pattern of effects was temporally consistent, there was some variability in the magnitude of effects among cycles. Questions were raised as to whether the intercycle variability was due to changes in effluent quality or due, at least in part, to other factors. The present study compares responses over the first three cycles, and shows that the choice of sentinel species is likely to be a major contributing factor to the variability in observed effects. Subset analyses using studies from mills that used the same sentinel species across cycles reveal fairly uniform responses and little evidence of significant improvements in overall fish health from cycles one to three. However, a meta-analysis using 1991 data collected from 10 mills before the implementation of the EEM program and data from the same mills collected during cycles one to three of the program reveal significantly reduced effects on relative liver weight and potential improvements in other endpoints. Environ. Toxicol. Chem. 2010;29:440–452. © 2009 SETAC [ABSTRACT FROM AUTHOR]

This study analysed 40 planning applications in the East of England to investigate the practice of translating paper recommendations in the environmental statement (ES) into legal conditions and obligations. A high proportion (50%) of suggested mitigation measures were not translated into planning conditions or obligations. However, a significant number of additional conditions or obligations, not directly based on the ES, were imposed on developers. The research suggests a mismatch between the practice of those producing ESs and the expectations of planning authorities, leading to inefficiency and, possibly, emasculation of environmental impact assessment through a failure to implement mitigation. Several recommendations are made to increase the effectiveness of the implementation and integration of mitigation measures. [ABSTRACT FROM AUTHOR]

This work describes a novel, simple and inexpensive pen-on-paper (PoP) method for patterning hydrophobic structures in paper substrates aiming the production of paper-based analytical devices (PADs). This fabrication protocol uses a commercially available plastic welding kit that can be easily acquired and is sold as a repair tool. It consists of an acrylate-based resin which is deposited on the paper and then cured using a UV led, or even the sunlight, for creation of the hydrophobic barriers. The protocol is instrument-free and can be easily implemented in any laboratory. To the best of our knowledge, this is the first report of the use of this material for production of analytical devices. The developed PADs were fully characterized and exhibited better chemical resistance than other recently reported PoP approaches regarding organic media and surfactants. Moreover, the fabrication method demonstrated good analytical versatility since it allowed the production of flexible devices, flow-based devices and pencil-drawn electrochemical devices. These findings are very interesting since overcome some limitations related by other PoP reports and expand the possibilities of using this technology in several aqueous and non-aqueous applications. Lastly, the analytical usefulness of the developed devices was successfully explored through colorimetric determination of nitrite. A detection limit of 0.14 mg L−1 was achieved and several samples of natural waters were analyzed. The results showed good agreement when compared with a reference technique. So, considering the simplicity and the results presented here, this fabrication method shows great potential for use in analytical chemistry. Image 1 • An instrumentless method for fabrication of paper analytical devices is proposed. • The hydrophobic barriers are created with a UV-curable resin used as repair tool. • The use of this material for fabrication of analytical devices is first described. • This material showed better chemical compatibility than other similar approaches. • Colorimetric and electrochemical applications were successfully explored. [ABSTRACT FROM AUTHOR]

This review paper provides an in-depth analysis of recent advancements in integrating two-dimensional (2D) materials with cellulose to enhance biosensing technology. The incorporation of 2D materials such as graphene and transition metal dichalcogenides, along with nanocellulose, improves the sensitivity, stability, and flexibility of biosensors. Practical applications of these advanced biosensors are explored in fields like medical diagnostics and environmental monitoring. This innovative approach is driving research opportunities and expanding the possibilities for diverse applications in this rapidly evolving field. [ABSTRACT FROM AUTHOR]

As the global urbanization process is further accelerating, the number of urban people is also steadily increasing. With the continuous growth of the urban population, the use of various functional facilities in the city is gradually becoming saturated, which seriously restricts the development of the city. Therefore, real-time perception and prediction of the operational status of various functional urban facilities, as well as environmental safety monitoring in the city, are of great significance for improving the functionality and livability of the city. In complex urban environments, multi-source data is interrelated, and the noise reduction of multi-source data and the integration of this correlation still face great challenges. At the same time, how to apply urban intelligent monitoring in the reconstruction of old cities is rarely mentioned. Based on the above problems, this paper proposes a data noise reduction model based on a wavelet algorithm and combines it with the Macroscopic Fundamental Diagram (MFD) multi-source data fusion structure proposed in this paper to provide a theoretical basis for the construction of an urban intelligent monitoring model. Then, the author constructed a data-driven urban safety environment monitoring model and a multi-source data-based urban congestion monitoring model, which have good experimental results and certain practical value. At the end of the paper, the author briefly discussed the application of the smart city monitoring model in the reconstruction of old cities, hoping to provide certain guidance for further integration in the future. [ABSTRACT FROM AUTHOR]