Smart Integrated Sensor for Multiple Detections of Glucose and L-Lactate Using On-Chip Electrochemical System

Multiple sensor electrodes, a supplementary electrode, a reference electrode, and signal-processing circuits were integrated on a single chip to develop a chip-shaped electrochemical sensing system. L-lactate and glucose were measured using on-chip working electrodes modified by polyion complex to immobilize lactate oxidase and glucose oxidase, respectively. Cyclic voltammetry measurements were conducted using an on-chip potentiostat. Selective and quantitative detection of glucose and L-lactate and the interference behavior were studied. Hydrogen peroxide generated by enzymatic reactions was detected by an increase in anodic oxidation current. Reaction currents at +0.7 V versus Ag/AgCl were used to obtain calibration plots. The measured dynamic ranges for L-lactate and glucose were 0.2–1.0 mM and 2.0–8.0 mM, respectively. The sensitivities were 65 nA/mM and 15 nA/mM, respectively, using a working electrode of 0.5 mm2. The 3σ detection limit was 0.19 mM and 1.1 mM, respectively. We have achieved multiple biomaterial detections on a circuit-equipped single chip. This integrated electrochemical sensor chip could be the best candidate for realizing point-of-care testing due to its portability and potential for mass production

Smartphone as a Portable Detector, Analytical Device, or Instrument Interface

The Encyclopedia Britannia defines a smartphone as a mobile telephone with a display screen, at the same time serves as a pocket watch, calendar, addresses book and calculator and uses its own operating system (OS). A smartphone is considered as a mobile telephone integrated to a handheld computer. As the market matured, solid-state computer memory and integrated circuits became less expensive over the following decade, smartphone became more computer-like, and more more-advanced services, and became ubiquitous with the introduction of mobile phone networks. The communication takes place for sending and receiving photographs, music, video clips, e-mails and more. The growing capabilities of handheld devices and transmission protocols have enabled a growing number of applications. The integration of camera, access Wi-Fi, payments, augmented reality or the global position system (GPS) are features that have been used for science because the users of smartphone have risen all over the world. This chapter deals with the importance of one of the most common communication channels, the smartphone and how it impregnates in the science. The technological characteristics of this device make it a useful tool in social sciences, medicine, chemistry, detections of contaminants, pesticides, drugs or others, like so detection of signals or image

Nanomaterials for Healthcare Biosensing Applications

In recent years, an increasing number of nanomaterials have been explored for their applications in biomedical diagnostics, making their applications in healthcare biosensing a rapidly evolving field. Nanomaterials introduce versatility to the sensing platforms and may even allow mobility between different detection mechanisms. The prospect of a combination of different nanomaterials allows an exploitation of their synergistic additive and novel properties for sensor development. This paper covers more than 290 research works since 2015, elaborating the diverse roles played by various nanomaterials in the biosensing field. Hence, we provide a comprehensive review of the healthcare sensing applications of nanomaterials, covering carbon allotrope-based, inorganic, and organic nanomaterials. These sensing systems are able to detect a wide variety of clinically relevant molecules, like nucleic acids, viruses, bacteria, cancer antigens, pharmaceuticals and narcotic drugs, toxins, contaminants, as well as entire cells in various sensing media, ranging from buffers to more complex environments such as urine, blood or sputum. Thus, the latest advancements reviewed in this paper hold tremendous potential for the application of nanomaterials in the early screening of diseases and point-of-care testing

Electrochemical biosensors based on nanomodified screen-printed electrodes: Recent applications in clinical analysis

This review addresses recent advances in the development of screen-printed electrode based biosensors modified with different nanomaterials such as carbon nanotubes, graphene, metallic nanoparticles as gold, silver and magnetic nanoparticles, and mediator nanoparticles (Prussian Blue, Cobalt Phthalocyanine, etc.), coupled with biological recognition elements such as enzymes, antibodies, DNA and aptamers to obtain probes with improved analytical features. Examples of clinical applications are illustrated, together with examples of paper-based electrochemical devices, of multiple detections using arrays of screen printed electrodes, and of the most recent developments in the field of wearable biosensors. Also the use of smartphones as final detectors is briefly depicted. © 2016 Elsevier B.V

Wireless communication and power harvesting in wearable contact lens sensors

The human eye contains multiple biomarkers related to various diseases, making electronic contact lens an ideal non-invasive platform for their diagnosis and treatment. Recent advances in technology have enabled the monitoring and diagnosis of glaucoma from Intraocular Pressure (IOP) detection, diabetes from glucose concentration detections, and other biosensors for pH and temperature sensing. Different sensor designs have led to distinct power transfer techniques, among which inductively coupled power transfer is considered most favourable for electronic contact lenses power delivery applications. Therefore, loop antenna, spiral shape antenna, and antenna with nanomaterials such as graphene and hybrid silver nanofibers have been explored under Industrial, Scientific, and Medical (ISM) frequency bands for both Wireless Power Transfer (WPT) and data communication. Notably, spiral antennas are also considered as the component of IOP sensing using capacitive sensors to detect the changes in frequency caused by pressure. This article reviews the state-of-the-art technologies in electronic contact lens sensors and their power delivery techniques. Herein, diverse sensing methods, materials, and power transfer techniques and the promising future trends and challenges in electronic contact lenses have been presented

Study on Integrated Redox Image Sensor Employing Square Wave Voltammetry

豊橋技術科学大

Advances in Wearable Sensing Technologies and Their Impact for Personalized and Preventive Medicine

Recent advances in miniaturized electronics, as well as mobile access to computational power, are fostering a rapid growth of wearable technologies. In particular, the application of such wearable technologies to health care enables to access more information from the patient than standard episodically testing conducted in health provider centres. Clinical, behavioural and self-monitored data collected by wearable devices provide a means for improving the early-stage detection and management of diseases as well as reducing the overall costs over more invasive standard diagnostics approaches. In this chapter, we will discuss some of the ongoing key innovations in materials science and micro/nano-fabrication technologies that are setting the basis for future personalized and preventive medicine devices and approaches. The design of wire- and power-less ultra-thin sensors fabricated on wearable biocompatible materials that can be placed in direct contact with the body tissues such as the skin will be reviewed, focusing on emerging solutions and bottlenecks. The application of nanotechnology for the fabrication of sophisticated miniaturized sensors will be presented. Exemplary sensor designs for the non-invasive measurement of ultra-low concentrations of important biomarkers will be discussed as case studies for the application of these emerging technologies

Electrochemical Plug-and-Power e-readers for Point-of-Care Applications

Point-of-Care diagnostic tests enable monitor health conditions and obtain fast results close to the patient, reducing medical costs, and allowing the control of infectious outbreaks. The interest in developing Point-of-Care devices is increasing due to they are suitable for a wide variety of applications. This doctoral thesis focuses on the development of Plug-and-Power electronic readers (e- readers) for electrochemical detections and the demonstration of their possibilities as Point-of-Care diagnostic testing. The solutions proposed in this study make it possible to improve Point-of-Care tests whose premises are laboratory decentralization, personalized medicine, rapid diagnosis, and improvement of patient care. Developed electronic readers can be powered from a conventional system, such as a USB port or a lithium battery, or can be defined as self-powered systems, capable of extracting energy from alternative energy sources, such as fuel cells, defining Plug-and-Power systems. The designed electrochemical detection devices in this thesis are based on low-power consumption electronic instrumentation circuits. These circuits are capable of controlling the sensing element, measuring its response, and representing the result quantitatively. The implemented devices can work with both electrochemical sensors and fuel cells. Furthermore, it is possible to adapt its measurement range, enabling its use in a wide variety of applications. Thanks to their reduced energy consumption, some of these developments can be defined as self-powered platforms able to operate only with the energy extracted from the biological sample, which in turn is monitored. These devices are easy-to-use and plug-and-play, enabling those unskilled individuals to carry out tests after prior training. Moreover, thanks to their user-friendly interface, results are clear and easy to understand. This doctoral dissertation is presented as an article compendium and composed of three publications detailed in chronological order of publication. The first contribution describes an innovative portable Point-of-Care device able to provide a quantitative result of the glucose concentration of a sample. The proposed system combines an e-reader and a disposable device based on two elements: a glucose paper-based power source, and a glucose fuel cell-based sensor. The battery-less e-reader extracts the energy from the disposable unit, acquires the signal, processes it, and shows the glucose concentration on a numerical display. Due to low-power consumption of the e-reader, the whole electronic system can operate only with the energy extracted from the disposable element. Furthermore, the proposed system minimizes the user interaction, which only must deposit the sample on the strip and wait a few seconds to see the test result. The second publication validates the e-reader in other scenarios following two approaches: using fuel cells as a power element, and as a dual powering and sensing element. The device was tested with glucose, urine, methanol, and ethanol fuel cells and electrochemical sensors in order to show the adaptability of this versatile concept to a wide variety of fields beyond clinical diagnostics, such as veterinary or environmental fields. The third study presents a low-cost, miniaturized, and customizable electronic reader for amperometric detections. The USB-powered portable device is composed of a full- custom electronic board for signal acquisition, and software, which controls the systems, represents and saves the results. In this study, the performance of the device was compared against three commercial potentiostats, showing comparable results to those obtained using three commercial systems, which were significantly more expensive. As proof of concept, the system was validated by detecting horseradish peroxidase samples. However, it could be easily extended its scope and measure other types of analytes or biological matrices since it can be easily adapted to detect currents a wide range of currents.Las pruebas de diagnostico Point-of-Care permiten monitorizar las condiciones de salud y obtener resultados rápidos cerca del paciente, reduciendo los costes médicos y permitiendo controlar brotes infecciosos. El interés por desarrollar dispositivos de Point- of-Care está aumentando debido a que son aplicables a una amplia variedad de aplicaciones. Esta tesis doctoral se centra en el desarrollo de lectores electrónicos (e-readers) Plug-and- Power para detecciones electroquímicas y la demostración de sus posibilidades como pruebas de diagnóstico de punto de atención (Point-of-Care). Las soluciones propuestas en este trabajo permiten mejorar las pruebas Point-of-Care, cuyas premisas son la descentralización de laboratorio, la medicina personalizada, el diagnóstico rápido y la mejora de la atención al paciente. Los lectores electrónicos desarrollados pueden ser alimentados desde un sistema convencional, como puede ser un puerto USB o una batería de litio, o definirse como sistemas autoalimentados, capaces de extraen energía de fuentes alternativas de energía, como celdas de combustible (fuel cells), definiendo así sistemas Plug-and-Power. Los dispositivos de detección electroquímica diseñados se basan en circuitos de instrumentación electrónica de bajo consumo. Estos circuitos son capaces controlar el elemento de sensado, medir su respuesta y representar el resultado de forma cuantitativa. Los dispositivos implementados pueden trabajar tanto con sensores electroquímicos como con fuel cells. Además, es posible adaptar su rango de medida, permitiendo su utilización en una amplia variedad de aplicaciones. Gracias a su reducido consumo de energía, algunos de estos desarrollos pueden definirse como plataformas autoalimentadas capaces de operar solo con la energía extraída de la muestra biológica, que a su vez es monitorizada. Estas plataformas electrónicas son fáciles de usar y Plug-and-Play, permitiendo que personas no cualificadas puedan utilizarlas después de un previo entrenamiento. Además, gracias a su interfaz fácil de usar, los resultados son claros y fáciles de interpretar

Ophthalmic sensing technologies for ocular disease diagnostics

Point-of-care diagnosis and personalized treatments are critical in ocular physiology and disease. Continuous sampling of tear fluid for ocular diagnosis is a need for further exploration. Several techniques have been developed for possible ophthalmological applications, from traditional spectroscopies to wearable sensors. Contact lenses are commonly used devices for vision correction, as well as for other therapeutic and cosmetic purposes. They are increasingly being developed into ocular sensors, being used to sense and monitor biochemical analytes in tear fluid, ocular surface temperature, intraocular pressure, and pH value. These sensors have had success in detecting ocular conditions, optimizing pharmaceutical treatments, and tracking treatment efficacy in point-of-care settings. However, there is a paucity of new and effective instrumentation reported in ophthalmology. Hence, this review will summarize the applied ophthalmic technologies for ocular diagnostics and tear monitoring, including both conventional and biosensing technologies. Besides applications of smart readout devices for continuous monitoring, targeted biomarkers are also discussed for the convenience of diagnosis of various ocular diseases. A further discussion is also provided for future aspects and market requirements related to the commercialization of novel types of contact lens sensors

Triboelectric Effect Enabled Self-Powered, Point-of-Care Diagnostics: Opportunities for developing ASSURED and REASSURED devices

The use of rapid point-of-care (PoC) diagnostics in conjunction with physiological signal monitoring has seen tremendous progress in their availability and uptake, particularly in low- and middle-income countries (LMICs). However, to truly overcome infrastructural and resource constraints, there is an urgent need for self-powered devices which can enable on-demand and/or continuous monitoring of patients. The past decade has seen the rapid rise of triboelectric nanogenerators (TENGs) as the choice for high-efficiency energy harvesting for developing self-powered systems as well as for use as sensors. This review provides an overview of the current state of the art of such wearable sensors and end-to-end solutions for physiological and biomarker monitoring. We further discuss the current constraints and bottlenecks of these devices and systems and provide an outlook on the development of TENG-enabled PoC/monitoring devices that could eventually meet criteria formulated specifically for use in LMICs.Ulster Universityhttp://www.mdpi.com/journal/micromachineshj2021Electrical, Electronic and Computer Engineerin