Sensor Technology in Neuroscience

Despite modern scientists’ best efforts, neuroscience, an extremely complex field that tries to comprehend the functionality of a human brain, is still in its infancy. There is much that is yet not understood in the human brain partly due to the limitations of existing tools and sensors, which are used to accurately probe and image the human brain. Successful development of devices and technologies for neuroscience requires interdisciplinary expertise in biosensors, chemistry, surface science, engineering and molecular biology. Taking into consideration the possibility of the diverse background of its readers, this book provides a simplified yet thorough treatment of the necessary topics needed for a researcher to develop either in vivo or in vitro sensors for the human brain. The topics of each chapter have been carefully chosen such that the reader can both understand the basic operating principles of different sensing techniques as well as be updated with the current state-of-the-art technology used for neurosensors. The book is very well organized, starting with An introduction to biosensor technology in Chapter 1, which gives the readers insight on a sensor’s anatomy, the necessity of receptors on sensors and how they can be attached on the sensor’s active surface. Receptors or probes that have excellent binding on the transducer will produce a sensor with high sensitivity and selectivity. To provide the reader with an overview of available sensor technology, this chapter also describes the mechanisms of different biosensors namely: electrochemical, piezoelectric or acoustic waves and optical. For each mechanism, the measuring methods of the biosensor are explained in detail. As an example, for electrochemical sensors, the governing equations and methodology of using potentiometry, amperometry and impedance spectroscopy were summarized and illustrated well with schematics. This chapter gives the reader an idea of which type of sensor could be suitable for his or her application. Chapter 2: The Cell-Substrate Surface Interaction, explains about how the cells interact on the surface of solids. This chapter is intended for different audiences; the first part is for non-chemists, which describes the basics of surface chemistry and how it will affect the behavior of cells. The second section, intended for non-biologists, introduces the reader to eukaryotic cells, their surrounding environment and the extracellular matrix. As the book is regarding development of sensors for neuroscience, a brief background on neurons, their anatomy, types, action potential and electrical conduction is described next. To study the behavior of neurons, it is often necessary to grow and culture them on the sensor. The final sections of this chapter illustrate the important factors to achieve cellular adhesion, growth and proliferation on different sensor substrates. Chapter 3: Electronic Detection Techniques, illustrates the electrogenic characteristics of the neuron which makes it possible for scientists to study the chemical reactions in the cell due to applied electrical excitation and vice versa. This chapter also describes the charge transfer that occurs at the neuro-electronic surface, which can be measured as subthreshold currents via microelectrode arrays and field effect transistors. Microelectrode arrays are often used for in vitro experiments and can be coupled with microfluidic lab on chips to create specific environmental conditions for the neurons. The miniature size of the sensors and array implementation allow rapid and parallel measurements, which have been used for toxicology tests and drug discovery. Chapter 4: Nanosensing the Brain illustrates the latest advancement in the field of neurosensors, where nanoparticles, nanotubes and nanowires are used to improve the sensitivity and accuracy of the microelectrode arrays and transistors described in Chapter 3. Chapter 5: The Vibrational Field and Detection of Neuron Behavior builds on the electrochemical, acoustic and optical sensing principles explained briefly in Chapter 1. Classical microscopy methods are plagued by detection limits and only provide information on the physical aspects of cells. Thus, the focus of this chapter is on the usage of label-free techniques that measure the frequencies and amplitudes of transducing signals in cells to detect molecular behavior and cellular events. Unlike the earlier chapters, which explain mainly about measuring tools and methods, Chapter 6: The Biomimetic Interface between Brain and Electrodes: Examples in the Design of Neural Prostheses, describes novel brain prosthetics which could be used to heal both the human brain and the functionality of disabled human bodies. This chapter is most interesting since it explores the wide range of possibilities that neural prostheses could be used, namely i) As electrodes in deep brain simulation to treat debilitating brain disorders such as Parkinson’s and epilepsy, ii) As motor cortex prostheses, which are brain-controlled robotic limbs that increase the mobility of paraplegics and amputees, iii) As retinal prosthetic interfaces to improve loss of vision due to the degeneration of the retina. The author concludes the book with Chapter 7: A Look at the Future, which provides prospective of future research in neuroscience. Promising research fields include quantum neurobiology, nanoneuromedicine, neuropharmacology, regenerative techniques, stem cells and many more. Overall, the book has been a very interesting read. The author has managed to explain and demystify the complex topic of neuroscience research using very clear and simple language. The best part about the book is that it does not require specific background knowledge of the topic, making it easy for readers of different disciplines to understand the operating principles and key design criteria for a neuro sensor. I would highly recommend the book for scientists that wish to start their research in the field of neuroscience, or for experienced neuroscientists that wish to explore alternative mechanisms for their sensors. -- Anis N. Nordin * Biosensors and Bioelectronics *
The book is very well organized Overall, the book has been a very interesting read. The author has managed to explain and demystify the complex topic of neuroscience research using very clear and simple language. The best part about the book is that it does not require specific background knowledge of the topic, making it easy for readers of different disciplines to understand the operating principles and key design criteria for a neuro sensor. I would highly recommend the book for scientists that wish to start their research in the field of neuroscience, or for experienced neuroscientists that wish to explore alternative mechanisms for their sensors. -- Dr. Anis N. Nordin * Biosensors & Bioelectronics *
This book, in the “RSC Detection Science” series, reviews applications of sensors in neuroscience and includes both traditional and innovative detection methods. Both in-vitro and in-vivo sensors are evaluated, with the greater focus on in-vitro techniques. Most of the in-vivo sensors are invasive, with a foreign-body response and other biocompatibility challenges limiting their long-term use. Refinement of existing sensors and development of new sensors based on nanoscience should eventually overcome these challenges for in-vivo sensors, with the ultimate objective being clinical applications. Contents The book has seven chapters. The first chapter introduces sensing technology, describing sensor elements and performance characteristics. The genesis of biosensors is reviewed through a history of the glucose sensor. Next, the focus shifts to technical aspects of a signal-transducing probe attached to a sensor substrate. The final part describes the physical principles of sensing based on electrochemistry and on acoustic and electromagnetic waves. The second chapter covers the interface between cells and sensor substrates. It details biological machinery involved in interactions with the cell surface, and the mechanisms of cell proliferation, survival, and migration. Attempts to improve biocompatibility of the manufactured substrate through alterations to morphology and structure of chemical coatings are reviewed. Discussion of blood–device interactions provides the context for long-term implantable biosensors. This chapter also contains a short primer on neurobiology, covering principles of electrical and chemical signaling in neurons. Chapter three describes electronic sensing of neuron electrical signals by use of traditional electrophysiological electrodes and field-effect transistors (FET). Almost the entire chapter is dedicated to measurement of neural activity of cultured neurons, neural networks, and mixed neuron–glia colonies in vitro on microfabricated devices, using microelectrode arrays (MEAs). The chapter describes how microfluidic devices are designed to manipulate the local chemical environment of cultured cells, and are used to employ cells as signal transducers for the sensors. Applications for drug discovery, toxicity testing, and studying neurological disease are discussed, with succinct descriptions of applications for Alzheimer’s and Parkinson’s disease and epilepsy. Chapter four, “Nanosensing the Brain”, reviews novel nanotechnology tools for brain study. Topics covered are: quantum dots for optical sensing; nanotubes, nanowires, and graphene for electrical and FET sensing; and mechanical sensing using nanoribbons. Chapter five covers sensing of neural activity using vibrational fields. First, electrochemical-impedance spectroscopy is described for two detection modes: an analyte specifically binding to and changing the sensor surface; or an analyte affecting cell electrical properties. Next, a brief review is provided of label-free detection of neuroactive substances at a metal–cell interface using surface plasmon resonance (SPR) and acoustic wave sensing . Finally, use of a Kelvin probe for detecting the electrical state of cells on the sensor surface is reviewed. A subchapter on brain electrical oscillations details the origin of waves in electroencephalography (EEG), from synchronization of ionic currents of particular families of ion channels to firing of neuronal ensembles. Chapter six describes brain–electrode interface, illustrated with examples from neural prosthetics. The authors examine foreign-body response and its implications for implanted biosensors. Deep-brain-stimulation electrodes are discussed as a clinical application. Also discussed are results from studies of cortical MEAs for brain–machine interface and retinal implants, with future applications for replacing damaged brain components. Chapter seven concludes the book with an overview of the future of sensor technology in the fields of quantum neurobiology, nanoneuromedicine, cognitive enhancers, and regenerative therapy. Comparison with the existing literature A similar book on sensors in neuroscience is Nanotechnology and Neuroscience: Nano-electronic, Photonic and Mechanical Neuronal Interfacing, edited by De Vittorio, Martiradonna, and Assad. It covers slightly different material, including optogenetics, with a greater focus on nanotechnology topics. A more general definition of the term “sensor” is provided in Methods in Mind by Senior, Russell, and Gazzaniga, which includes a review of such traditional behavioral neuroscience techniques as tracking eye movement and measuring skin conductance. Additionally, Electrochemical Methods for Neuroscience edited by Michael and Borland is a perfect complementary book on electrochemical sensing in nervous systems. Critical assessment This book has the difficult task of covering the fast-developing topic of sensors in neuroscience in just 200 pages. The current multidisciplinary approach to neuroscience requires clear communication between scientists from different fields. The authors succeed in this by providing concise explanations of complex physical and biological concepts, including plasmon resonance and the origins of Alzheimer’s disease. A noticeable disadvantage of the book is a lack of discussion of electrochemical sensing and microdialysis applications. These techniques are mature, and can provide unique insight into the challenges and solutions of invivo sensing in the brains of animals displaying the behaviour under investigation. Summary This book contains an up-to-date overview of sensor technology used in neuroscience. The modular structure of the book makes it easy to review topics independently of each other. The authors explain both the physical basis of sensor design and the biological origins of the generated signal. The use of sensors in vitro is the main focus of the book, with a smaller portion of the text dedicated to in-vivo invasive sensors and a thorough description of the complications associated with this approach. The book can be used by scientists and engineers in related subjects as a comprehensive source of insight into sensor technology in neuroscience. -- Pavel Takmakov * Anal Bioanal Chem DOI 10.1007/s00216-014-7939-9 *
This book, in the "RSC Detection Science" series, reviews applications of sensors in neuroscience and includes both traditional and innovative detection methods. Both in-vitro and in-vivo sensors are evaluated, with the greater focus on in-vitro techniques. Most of the in-vivo sensors are invasive, with a foreign-body response and other biocompatibility challenges limiting their long-term use. Refinement of existing sensors and development of new sensors based on nanoscience should eventually overcome these challenges for in-vivo sensors, with the ultimate objective being clinical applications. The book has seven chapters. The first chapter introduces sensing technology, describing sensor elements and performance characteristics. The genesis of biosensors is reviewed through a history of the glucose sensor. Next, the focus shifts to technical aspects of a signal-transducing probe attached to a sensor substrate. The final part describes the physical principles of sensing based on electrochemistry and on acoustic and electromagnetic waves. The second chapter covers the interface between cells and sensor substrates. It details biological machinery involved in interactions with the cell surface, and the mechanisms of cell proliferation, survival, and migration. Attempts to improve biocompatibility of the manufactured substrate through alterations to morphology and structure of chemical coatings are reviewed. Discussion of blood–device interactions provides the context for long-term implantable biosensors. This chapter also contains a short primer on neurobiology, covering principles of electrical and chemical signaling in neurons. Chapter three describes electronic sensing of neuron electrical signals by use of traditional elect...