Field Effect Transistor Nanosensor for Breast Cancer Diagnostics

Silicon nanochannel field effect transistor (FET) biosensors are one of the most promising technologies in the development of highly sensitive and label-free analyte detection for cancer diagnostics. With their exceptional electrical properties and small dimensions, silicon nanochannels are ideally suited for extraordinarily high sensitivity. In fact, the high surface-to-volume ratios of these systems make single molecule detection possible. Further, FET biosensors offer the benefits of high speed, low cost, and high yield manufacturing, without sacrificing the sensitivity typical for traditional optical methods in diagnostics. Top down manufacturing methods leverage advantages in Complementary Metal Oxide Semiconductor (CMOS) technologies, making richly multiplexed sensor arrays a reality. Here, we discuss the fabrication and use of silicon nanochannel FET devices as biosensors for breast cancer diagnosis and monitoring

THE ACOUSTIC WAVE SENSOR AND SOFT LITHOGRAPHY TECHNOLOGIES FOR CELL BIOLOGICAL STUDIES

Recently, cell-based biosensors have attracted many attentions because of their potential applications in fundamental biological research, drug development, and other fields. Acoustic wave biosensors offer powerful tools to probe cell behaviors and properties in a non-invasive, simple, and quantitative manner. Current studies on cell-based acoustic wave sensors are focused on experimental investigation of thickness shear mode (TSM) sensors for monitoring cell attachment and spreading. There are no theoretical models for cell-based TSM biosensors. No studies on other cell biological applications of TSM sensors or on surface acoustic wave cell-based biosensors have been performed. The reliability and sensitivity of current cell-based biosensors are low. Improving them requires studies on engineering cells and understanding the effects of cell morphology on cell function.The overall objective of this dissertation is to develop acoustic wave sensor systems for cell biological studies and to determine the effects of cell shape on cell function. Our study includes three parts: (1) Development of cell-based TSM sensor system; (2) Studies of Love mode devices as cell-based biosensors; (3) Studies of the effects of cell shape on cell function. In the first part, a theoretical model was developed, changes in cell adhesion were monitored and cell viscoelasticity was characterized by TSM sensor systems. The TSM sensor systems were demonstrated to provide a non-invasive, simple, and reliable method to monitor cell adhesion and characterize cell viscoelasticity. In the second part, a theoretical model was developed to determine signal changes in Love mode sensors due to cells attaching on their surface. Experimental results validated the model. In the third part, cell shape was patterned to different aspect ratios. Elongated tendon cells were found to express higher collagen type I than shorter cells. Changes in cell shape induced alterations in cytoskeleton, focal adhesions, and traction forces in cells, which may collectively prompt the observed differential collagen type I expression in cells with different shapes. Overall, our research expanded the applications of acoustic wave cell-based biosensors. Studies on cell shape control and the effects of cell shape on cell function will be useful for increasing the sensitivity of cell-based biosensors in future research

Application of nanoparticles in electrochemical sensors and biosensors

The unique chemical and physical properties of nanoparticles make them extremely suitable for designing new and improved sensing devices, especially electrochemical sensors and biosensors. Many kinds of nanoparticles, such as metal, oxide and semiconductor nanoparticles have been used for constructing electrochemical sensors and biosensors, and these nanoparticles play different roles in different sensing systems. The important functions provided by nanoparticles include the immobilization of biomolecules, the catalysis of electrochemical reactions, the enhancement of electron transfer between electrode surfaces and proteins, labeling of biomolecules and even acting as reactant. This minireview addresses recent advances in nanoparticle-based electrochemical sensors and biosensors, and summarizes the main functions of nanoparticles in these sensor systems

Fully Integrated Biochip Platforms for Advanced Healthcare

Recent advances in microelectronics and biosensors are enabling developments of innovative biochips for advanced healthcare by providing fully integrated platforms for continuous monitoring of a large set of human disease biomarkers. Continuous monitoring of several human metabolites can be addressed by using fully integrated and minimally invasive devices located in the sub-cutis, typically in the peritoneal region. This extends the techniques of continuous monitoring of glucose currently being pursued with diabetic patients. However, several issues have to be considered in order to succeed in developing fully integrated and minimally invasive implantable devices. These innovative devices require a high-degree of integration, minimal invasive surgery, long-term biocompatibility, security and privacy in data transmission, high reliability, high reproducibility, high specificity, low detection limit and high sensitivity. Recent advances in the field have already proposed possible solutions for several of these issues. The aim of the present paper is to present a broad spectrum of recent results and to propose future directions of development in order to obtain fully implantable systems for the continuous monitoring of the human metabolism in advanced healthcare applications

Establishment of surface functionalization methods for spore-based biosensors and implementation into sensor technologies for aseptic food processing

Aseptic processing has become a popular technology to increase the shelf-life of packaged products and to provide non-contaminated goods to the consumers. In 2017, the global aseptic market was evaluated to be about 39.5 billion USD. Many liquid food products, like juice or milk, are delivered to customers every day by employing aseptic filling machines. They can operate around 12,000 ready-packaged products per hour (e.g., Pure-Pak® Aseptic Filling Line E-PS120A). However, they need to be routinely validated to guarantee contamination-free goods. The state-of-the-art methods to validate such machines are by means of microbiological analyses, where bacterial spores are used as test organisms because of their high resistance against several sterilants (e.g., gaseous hydrogen peroxide). The main disadvantage of the aforementioned tests is time: it takes at least 36-48 hours to get the results, i.e., the products cannot be delivered to customers without the validation certificate. Just in this example, in 36 hours, 432,000 products would be on hold for dispatchment; if more machines are evaluated, this number would linearly grow and at the end, the costs (only for waiting for the results) would be considerably high. For this reason, it is very valuable to develop new sensor technologies to overcome this issue. Therefore, the main focus of this thesis is on the further development of a spore-based biosensor; this sensor can determine the viability of spores after being sterilized with hydrogen peroxide. However, the immobilization strategy as well as its implementation on sensing elements and a more detailed investigation regarding its operating principle are missing. In this thesis, an immobilization strategy is developed to withstand harsh conditions (high temperatures, oxidizing environment) for spore-based biosensors applied in aseptic processing. A systematic investigation of the surface functionalization’s effect (e.g., hydroxylation) on sensors (e.g., electrolyte-insulator semiconductor (EIS) chips) is presented. Later on, organosilanes are analyzed for the immobilization of bacterial spores on different sensor surfaces. The electrical properties of the immobilization layer are studied as well as its resistance to a sterilization process with gaseous hydrogen peroxide. In addition, a sensor array consisting of a calorimetric gas sensor and a spore-based biosensor to measure hydrogen peroxide concentrations and the spores’ viability at the same time is proposed to evaluate the efficacy of sterilization processes

The future of biosensors

Since the development of the glucose sensor by Clark and Lyons in 1962, generally recognized as the first biosensor, many types of sensors have been developed in which a physical or chemical transducer is provided with a layer containing a biological sensing element. The resulting device is called a biosensor, aimed to produce an electronic signal as a function of the concentration of a chemical or biochemical constituent of a liquid, not necessarily of biological origin. Among the many proposed concepts, the integration of biologically active materials with a silicon chip is one of the most intriguing approaches, because it seems the most comprehensive integration between biology and electronics. In this paper the resulting biochips, mainly based on the field-effect principle as the coupling mechanism between the two domains, will be described and discussed with an outlook on the future

Recent Progress in Optical Sensors for Biomedical Diagnostics

In recent years, several types of optical sensors have been probed for their aptitude in healthcare biosensing, making their applications in biomedical diagnostics a rapidly evolving subject. Optical sensors show versatility amongst different receptor types and even permit the integration of different detection mechanisms. Such conjugated sensing platforms facilitate the exploitation of their neoteric synergistic characteristics for sensor fabrication. This paper covers nearly 250 research articles since 2016 representing the emerging interest in rapid, reproducible and ultrasensitive assays in clinical analysis. Therefore, we present an elaborate review of biomedical diagnostics with the help of optical sensors working on varied principles such as surface plasmon resonance, localised surface plasmon resonance, evanescent wave fluorescence, bioluminescence and several others. These sensors are capable of investigating toxins, proteins, pathogens, disease biomarkers and whole cells in varied sensing media ranging from water to buffer to more complex environments such as serum, blood or urine. Hence, the recent trends discussed in this review hold enormous potential for the widespread use of optical sensors in early-stage disease prediction and point-of-care testing devices.DFG, 428780268, Biomimetische Rezeptoren auf NanoMIP-Basis zur Virenerkennung und -entfernung mittels integrierter Ansätz

Carrier systems and biosensors for biomedical applications.

This chapter addresses both carrier systems and biosensors which are often applied directly to tissues, either as skin patches, implanted or ingested by a variety of routes. It follows that there is a common theme between these applications and many of those discussed elsewhere within this book. Any device, scaffold or implant within the body must usually display extreme biocompatibility if it is not to cause harm to the patient. The techniques of tailoring surfaces to ensure no adverse reactions are a common theme running throughout this work on tissue engineering

Developments in nanoparticles for use in biosensors to assess food safety and quality

The following will provide an overview on how advances in nanoparticle technology have contributed towards developing biosensors to screen for safety and quality markers associated with foods. The novel properties of nanoparticles will be described and how such characteristics have been exploited in sensor design will be provided. All the biosensor formats were initially developed for the health care sector to meet the demand for point-of-care diagnostics. As a consequence, research has been directed towards miniaturization thereby reducing the sample volume to nanolitres. However, the needs of the food sector are very different which may ultimately limit commercial application of nanoparticle based nanosensors. © 2014 Elsevier Ltd