Sensor design on inexpensive substrates for biochemical applications

2017-03-02T00:16:25Z (GMT) by Li, Miaosi
This research project focuses on exploring new sensor design methods on inexpensive substrates for various biomedical and chemical applications, in order to improve the health and life quality of people living in less-industrialized countries and remote regions. People living in these areas are more susceptible to diseases due to shortage of funds, medical facilities, medical knowledge and professional staff. This project has noticed that for most existing point-of-care diagnostics designed for developing areas, although are affordable, sensitive, specific and rapid (“ASSR”), cannot be practically utilized in these areas, for they are not easily operated by non-professional and untrained personnel. In particular, a desirable user-oriented device is required to be user-friendly, equipment-free and delivered to end-users (“UED”), and achieving these demands, therefore, is the aim of this project. This thesis includes two parts, presenting two original sensor design concepts respectively. One is the “sample-only” method, which only requires the user to introduce the sample to the sensor with no extra effort during the assay; the other one is the “text-reporting” method, which can report the assay result directly with unambiguous text messages to the user. Both of the two concepts effectively address the “UED” problems in existing devices. The sensors developed by the new design concepts were conducted through fabrication on inexpensive substrates, which are cellulose paper and plastic (or glass) slides throughout this research. The patterning of these substrates is processed through traditional industrialized surface treatment, paper-sizing and printing techniques, making the devices affordable and easily-obtained. The feasibility of these two concepts is then demonstrated through applying them to practical applications. The first application is blood typing. The “sample-only” method allows the user to get clear blood typing results by only introducing one blood drop during the assay. The “text-reporting” method designs the first paper-based blood typing device that reports a patient’s blood type in written text, which enables non-professional users to determine the blood types immediately. Furthermore, the “text-reporting” method also presents its desirable features in another application: environmental monitoring. With the help of text-based information, even untrained users can quickly and simply obtain the testing result of contaminates in water at home, in the field, in emergency and many other areas where laboratories are not readily available. None of these applications requires supporting equipment and personnel for assay analysis and result interpretation. The applications performed by the new sensor design methods in this project bring the test immediately and conveniently to the patients or end-users, and effectively reduce the high-dependency of testing on hospitals or central laboratories. The sensor design concepts explored in this project establish the “ASSURED” platform which is highly practical for use by non-professional users in developing countries. These methods also hold enormous potential for integration with future work, which would strongly drive the development of products for point-of-care, telemedicine and on-site environmental sensing.