Abstract
The need for portable and inexpensive analytical devices for various critical issues has led researchers to seek novel materials to construct them. Soft porous materials, such as paper and sponges, are ideal candidates for fabricating such devices due to their light weight and high availability. More importantly, their great compatibility toward modifications and add-ons allows them to be customized to match different objectives. As a result, porous material-based composites have been extensively used to construct sensing devices applied in various fields, such as point-of-care testing, environmental sensing, and human motion detection. In this article, we present fundamental thoughts on how to design a sensing device based on these interesting composite materials and provide correlated examples for reader’s references. First, a rundown of devices made with porous composite materials starting from their fabrication techniques and compatible detection methods is given. Thereafter, illustrations are provided on how device function and property improvements are achieved with a delicate use of composite materials. This includes extending device lifetime by using polymer films to protect the base material, while signal readout can be enhanced by a careful selection of protective cover and the application of advanced photo image analysis techniques. In addition to chemical sensors, mechanical responsive devices based on conductive composite materials are also discussed with a focus on base material selection and platform design. We hope the ideas and discussions presented in this article can help researchers interested in designing sensing devices understand the importance and usefulness of composite materials.
Highlights
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A porous paper material-based microfluidic chip designed by Reboud et al delivers the full DNA diagnostics of malaria in blood samples, including sample preparation from whole-blood, isothermal amplification, and visualization of the output properties [4]
In another design proposed by Hiraoka et al, a distance-based sensor using composites of porous paper and a combination of chrome azurol S, lead chloride, tetrabromophenol blue, and citric buffer allows an instrument-free naked-eye evaluation of human urinary albumin/creatinine ratio in 15 min [5]
Summary
The importance of inexpensive and portable analytical devices is on the rise due to critical issues such as point-of-care application, chemical and biological detection, and environmental pollutant sensing. Porous material-based composites, which are obtained by physical or chemical modification of native porous materials, retain the base materials’ favorable physical properties They are ideal for portable sensing devices because of their low weight, while the rendering large surface area allows efficient chemical processing. A porous paper material-based microfluidic chip designed by Reboud et al delivers the full DNA diagnostics of malaria in blood samples, including sample preparation from whole-blood, isothermal amplification, and visualization of the output properties [4]. Which can combine with various chemical reagents for simultaneous detection of Cd(II), Pb(II), Cu(II), Fe(II), and Ni(II) ions [6] As demonstrated in these sensing devices, porous material-based composites are incredibly useful and potent when an analytical platform is designed. At the end of this article, a discussion of future challenges and perspective opportunities are provided, which should be helpful for researchers planning to work on these exciting composite materials
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