This article aims to review nature-inspired chemical sensors for enabling fast, relatively inexpensive, and minimally (or non-) invasive diagnostics and follow-up of the health conditions. It can be achieved via monitoring of biomarkers and volatile biomarkers, that are excreted from one or combination of body fluids (breath, sweat, saliva, urine, seminal fluid, nipple aspirate fluid, tears, stool, blood, interstitial fluid, and cerebrospinal fluid). The first part of the review gives an updated compilation of the biomarkers linked with specific sickness and/or sampling origin. The other part of the review provides a didactic examination of the concepts and approaches related to the emerging chemistries, sensing materials, and transduction techniques used for biomarker-based medical evaluations. The strengths and pitfalls of each approach are discussed and criticized. Future perspective with relation to the information and communication era is presented and discussed.

This article is an overview of the present and ongoing developments in the field of nanomaterial-based sensors for enabling fast, relatively inexpensive and minimally (or non-) invasive diagnostics of health conditions with follow-up by detecting volatile organic compounds (VOCs) excreted from one or combination of human body fluids and tissues (e.g., blood, urine, breath, skin). Part of the review provides a didactic examination of the concepts and approaches related to emerging sensing materials and transduction techniques linked with the VOC-based non-invasive medical evaluations. We also present and discuss diverse characteristics of these innovative sensors, such as their mode of operation, sensitivity, selectivity and response time, as well as the major approaches proposed for enhancing their ability as hybrid sensors to afford multidimensional sensing and information-based sensing. The other parts of the review give an updated compilation of the past and currently available VOC-based sensors for disease diagnostics. This compilation summarizes all VOCs identified in relation to sickness and sampling origin that links these data with advanced nanomaterial-based sensing technologies. Both strength and pitfalls are discussed and criticized, particularly from the perspective of the information and communication era. Further ideas regarding improvement of sensors, sensor arrays, sensing devices and the proposed workflow are also included.

The detection of many diseases is missed because of delayed diagnoses or the low efficacy of some treatments. This emphasizes the urgent need for inexpensive and minimally invasive technologies that would allow efficient early detection, stratifying the population for personalized therapy, and improving the efficacy of rapid bed-side assessment of treatment. An emerging approach that has a high potential to fulfill these needs is based on so-called "volatolomics", namely, chemical processes involving profiles of highly volatile organic compounds (VOCs) emitted from body fluids, including breath, skin, urine and blood. This article presents a didactic review of some of the main advances related to the use of nanomaterial-based solid-state and flexible sensors, and related artificially intelligent sensing arrays for the detection and monitoring of disease with volatolomics. The article attempts to review the technological gaps and confounding factors related to VOC testing. Different ways to choose nanomaterial-based sensors are discussed, while considering the profiles of targeted volatile markers and possible limitations of applying the sensing approach. Perspectives for taking volatolomics to a new level in the field of diagnostics are highlighted.

No abstract

1 of 8) 1600187 wileyonlinelibrary.combased on a thin film of molecularly modified nanoparticles deposited on top of a self-healing synthetic polyurethane layer that is patterned with self-healing electrodes. The sensor exhibited sensitivity to pressure and strain that is highly comparable to other technologies. Moreover, the same self-healing platform was sensitive to both polar and nonpolar VOCs, with a detection limit of 20 ppb. This self-healing device was adapted after small changes in its architecture to high resolution temperature sensor. The main challenge with this sensor was that the healing process could not be controlled by the intrinsic features of the sensing layer (molecularly modified nanoparticles), but rather it was induced by the process of intrinsic self-healing of the polyurethane substrate beneath it. In many instances, this induced healing ability causes several problems, such as low mechanical properties and loss of electrical conductivity of the healed film, which are harmful to the sensor.We now report on the development of a truly self-healing active sensing layer, i.e., a sensing layer that can heal itself intrinsically. To obtain both self-healing ability and electronic properties, active composites of self-healing polymers and 0D, 1D, and 2D carbon nanomaterials (and, for the sake of comparison, ionic nanomaterials) are used as a background of this investigation. The self-healing features of the composite-based sensing layers are examined and a proof-of-concept of their application for long-term monitoring or updating of human health through VOCs sensing is discussed. [20][21][22] Result and DiscussionThree different self-healing polymers (poly(propylene-urethaneureaphenyl-disulfide) PPUU-2S, poly(urethane-carboxyphenyl-disulfide) PUC-2S, and poly(2-hydroxypropyl methacrylate)/poly(ethyleneimine) PPMA/PEI) and 4 conductive materials (carbon black -CB, carbon nanotube -CNT, graphite, and lithium perchlorate -LiClO 4 ) (Figure 1a) were used for preparation of self-healing composites. The polymers have both flexible and self-healing features. The use of carbon structures are prefered because they are inexpensive, affordable, and their synthesis is well-established. We have then taken Despite recent dramatic development of materials with self-healing ability, fabrication of a self-healing devices remains challenging. In this paper, truly self-healing composites consisting polymers and carbon nanostructures are reported. Using a modified fabrication technique -called "layer-by-layer stamping" -chemical sensors are produced and characterized by infrared spectroscopy and various microscopy techniques. As a demonstration of the ability of the developed sensors to coexist with harsh operation conditions, the performance of the sensors under exposure to volatile organic compounds that are derived from human breath/skin is evaluated under different conditions of cutting and self-healing cycles. The results show a discrimination ability of the selected sensors to return to an operation level of...