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Herein, we describe the development of a paper-based device to detect nucleic acids of pathogens of interest in complex samples using loop-mediated isothermal amplification (LAMP) by producing a colorimetric response visible to the human eye. To demonstrate the utility of this device in emerging public health emergencies, we developed and optimized our device to detect SARS-CoV-2 in human saliva without preprocessing. The resulting device was capable of detecting the virus within 60 min and had an analytical sensitivity of 97% and a specificity of 100% with a limit of detection of 200 genomic copies/μL of patient saliva using image analysis. The device consists of a configurable number of reaction zones constructed of Grade 222 chromatography paper separated by 20 mil polystyrene spacers attached to a Melinex® backing via an ARclean® double-sided adhesive. The resulting device is easily configurable to detect multiple targets and has the potential to detect a variety of pathogens simply by changing the LAMP primer sets.

This chapter mainly focuses on the recent developments made in rapid detection of cancer cells using novel paper-based analytical devices (PADs). Due to their simplicity, portability and biocompatibility, PADs have gained great attention in recent years for rapid detection of biomarkers. Since cancer has become an increasing worldwide concern, there stands an imminent requirement for minimally invasive detection and monitoring techniques. The progress made in paper-based detection of cancer biomarkers has proven to hold great potential for the development of point-of-care (POC) diagnostic devices for early detection of tumor cells. In this chapter, after an introduction on paper diagnosis, we will provide a brief explanation on the fabrication methods used for PADs. Then recently developed sensors based on colorimetric, fluorescence, chemiluminescence (CL), electrochemical, electrochemiluminescence (ECL) and surface-enhanced Raman scattering (SERS) techniques will be elaborated. In the end, current limitations and problems hindering the commercialization of paper-based sensors will be pointed out.

This chapter presents and discusses the most usual methodologies for colorimetric detection on paper-based analytical devices (PADs). State of the art associated with pioneering, popularity, physical aspect, surface modifications, instrumental and instrumental-free colorimetric measurements are carefully presented. Moreover, a side-by-side comparison among the most usual colorimetric detection modes on PADs was performed using a well-known complexometric reaction model. The pros and cons were discussed to show their advantages for chemical analysis.

This chapter describes the concept of paper space. Covered are the primary reasons for using paper space, how to get in/out of paper space, and how to set up title blocks (layouts), viewports and their properties, viewport scale assignments, controlling what is visible in viewports, setting up text and dim styles in viewports, and the annotative concept.

A simple cellulosic (C6H10O5)n substance, paper has many applications in addition to its use in writing, painting, and packaging. Papers have long been used in analytical chemistry; however, recently, their use in the development of cheaper portable sensors and energy storage devices has been explored. These paper-based environmental sensing devices are providing faster and simpler contaminant detection, along with the removal of sample storage and transportation. In addition to chemical pollutant detectors, the paper-based sensors are also being developed for the gases and volatile compounds. Such paper-based sensors will be very useful in rapid detection of toxic gases during any emergency. . These easy and cheap paper-based devices will be very useful for the developing countries, where environmental pollution concentration is very high and the sophisticated analytical laboratories are not easily accessible. Along with the exponentially increasing in pollution level, our energy demands have also increased by the same pace. Modern-day electronic devices and electric vehicles need robust energy storage devices, and our conventional batteries are not efficient for it. Therefore the supercapacitor has emerged as a solution to this problem; it is a rechargeable, high energy density and quick-release energy storage device, and the use of paper in its development let it to be used in deformable electronic devices.

This work was supported by the research group "Ciencia y Cultura del Patrimonio"(HUM-1057) and the Ministerio de Economia y Competitividad in the framework of the I + D research project "Nuevas alternativas al conocimiento de los materiales y los procesos de conservacion y restauracion de obra grafica y patrimonio documental"(REF.MAT2014-58659-P). Funding for open access charge: Universidad de Granada/CBUA., This study offers a new tool to restorers to bleach paper documents: artificial light radiation (ALR). It is a controlled method that is an alternative to other highly aggressive procedures that have been applied to cellulose based media. Its main novelty is its intrinsic lighting characteristics which guarantee uniformity and avoid heating the paper. The results of testing this new tool were compared to those of bleaching with hydrogen peroxide (H2O2). Each of the two methods was applied to five different types of widely used paper: Arches and Somerset (brands serving for engraving and digital printing), Ingres (drawing), press-type (magazines and newspapers) and Bible-type (historical documents). Once characterised by physico-mechanical, chemical and optical parameters (grammage, thickness, specular gloss, optical properties, air permeance, tensile properties, determining the pH of both surface and aqueous extracts), the different papers were bleached by the two methods according to pre-established criteria. Finally, to determine the evolution and effects of the two treatments, the papers were subjected to accelerated ageing., Research group "Ciencia y Cultura del Patrimonio" HUM-1057, Spanish Government MAT2014-58659-P, Universidad de Granada/CBUA

Microfluidic paper-based analytical devices, so-called μPADs, were presented for the first time by Whitesides and colleagues in 2007. Since then, several research groups have focused on designing, synthesizing, and investigating the role of microfluidic paper-based devices in different applications including biosensors, drug delivery, gene delivery, and so on. In this chapter, we focused on different aspects of them, to provide an applicable perspective as well as review the recent advances in this field.