Biosensors & Bioelectronics

Graphene based enzymatic and non-enzymatic electrodes can efficiently detect glucose, cytochrome-c, NADH, hemoglobin, HRP, and cholesterol, hydrogen peroxide, AA, UA, DA, respectively. Nanocapsules are nanoscale shells made out of a nontoxic polymer. They are vesicular systems that are made up of a polymeric membrane which encapsulates an inner liquid core at the nanoscale level. Nanocapsules have a myriad of uses, which include promising medical applications for drug delivery, food enhancement, nutraceuticals, and for the self-healing of materials

A biotransducer is the recognition-transduction component of a biosensor system. It consists of two intimately coupled parts; a bio-recognition layer and a physicochemical transducer, which acting together converts a biochemical signal to an electronic or optical signal. Electronic biosensing offers significant advantages over optical, biochemical and biophysical methods, in terms of high sensitivity and new sensing mechanisms, high spatial resolution for localized detection, facile integration with standard wafer-scale semiconductor processing and label-free, real-time detection in a nondestructive manner. Gravimetric biosensors use the basic principle of a response to a change in mass.

Immense potentiality of biosensors in medical diagnostics has driven scientists in evolution of biosensor technologies and innovating newer tools in time. The cornerstone of the popularity of biosensors in sensing wide range of biomolecules in medical diagnostics is due to their simplicity in operation, higher sensitivity, ability to perform multiplex analysis, and capability to be integrated with different function by the same chip. There remains a huge challenge to meet the demands of performance and yield to its simplicity and affordability. Ultimate goal stands for providing point-of-care testing facility to the remote areas worldwide, particularly the developing countries. It entails continuous development in technology towards multiplexing ability, fabrication, and miniaturization of biosensor devices so that they can provide lab-on-chip-analysis systems to the community.

The field of optical biosensors has been a growing research area over the last three decades. A wide range of books and review articles has been published by experts in the field who have highlighted the advantages of optical sensing over other transduction methods. Fluorescence is by far the method most often applied and comes in a variety of schemes. Nowadays, one of the most common approaches in the field of optical biosensors is to combine the high sensitivity of fluorescence detection in combination with the high selectivity provided by ligand-binding proteins. In this chapter we deal with reviewing our recent results on the implementation of fluorescence-based sensors for monitoring environmentally hazardous gas molecules.

Biomedical engineering (BME) is the application of engineering principles and design concepts to medicine and biology for healthcare purposes (e.g. diagnostic or therapeutic). This field seeks to close the gap between engineering and medicine: It combines the design and problem solving skills of engineering with medical and biological sciences to advance health care treatment, including diagnosis, monitoring, and therapy. To ensure that good quality assurance practices are used for the design of medical devices and that they are consistent with quality system requirements worldwide, the Food and Drug Administration revised the Current Good Manufacturing Practice (CGMP) requirements by incorporating them into the Quality System Regulation, 21 CFR Part 820. An important component of the revision is the addition of design controls.

The majority of reported biosensor research has been directed toward development of devices for clinical markets; however, driven by a need for better methods for environmental surveillance, research into this technology is also expanding to encompass environmental applications. Biosensors are biophysical devices which can detect the presence of specific substances e.g. sugars, proteins, hormones, pollutants and a variety of toxins in the environment. They are also capable of measuring the quantities of these specific substances in the environment.

Wearable biosensors are garnering substantial interest due to their potential to provide continuous, real-time physiological information via dynamic, noninvasive measurements of biochemical markers in biofluids, such as sweat, tears, saliva and interstitial fluid. Recent developments have focused on electrochemical and optical biosensors, together with advances in the noninvasive monitoring of biomarkers including metabolites, bacteria and hormones. A combination of multiplexed biosensing, microfluidic sampling and transport systems have been integrated, miniaturized and combined with flexible materials for improved wearability and ease of operation. 

Micro-/nanoelectromechanical systems (MEMS/NEMS) micro-/nanoelectromechanical system (MEMS/NEMS) need to be designed to perform expected functions in short durations, typically in the millisecond to picosecond range. Most mechanical properties are known to be scale dependent, therefore the properties of nanoscale structures need to be measured. For bioMEMS/bioNEMS, bioMEMS/bioNEMS adhesion between biological molecular layer molecular layers and the substrate, and friction and wear of biological layers, can be important. Bionics is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology Bionics means the replacement or enhancement of organs or other body parts by mechanical versions. 

Biological properties can be measured and altered using electronics, magnetics, photonics, sensors, circuits, and algorithms. Applications range from basic biological science through clinical medicine, and enable new discoveries, diagnoses, and treatments by creating novel devices, systems, and analyses. Biomolecular Electronics is a branch of nano-science and technology dealing with the investigation and the technological exploitation of electron transport properties in special classes of biomolecules. Albeit it deals with molecules that can donate to or receive electrons, biomolecular electronics has nothing to do with the molecular bases ruling the generation and propagation of electrical signals in neural cells, i.e. the action potential.

Biosensors & bioelectronics research trends in the field of Neuroprosthetics. Driven by advances in microelectronics, computing and microsystem integration, it has now become possible to develop devices that effectively interface and interact with the nervous system. This programme aims at providing the technology for animal and clinical studies, such as neural recording, electrical neurostimulation, optogenetic stimulation and multi-modal neuromodulation to understand and listen to the brain better, in particular the cortex, the cerebellum and the thalamus.

Nanoelectronics is the term used in the field of nanotechnology for electronic components and research on improvements of electronics such as display, size, and power consumption of the device for the practical use. This includes research on memory chips and surface physical modifications on the electronic devices. Nanoelectronics cover quantum mechanical properties of the hybrid material, semiconductor, single dimensional nanotubes, nanowires, and so forth. Well-developed nanoelectronics can be applied in different fields, and are especially useful for detecting disease-causing agents and disease biomarkers.

Aptamers are oligonucleotide or peptide molecules that bind to a specific target molecule. Aptamers are usually created by selecting them from a large random sequence pool, but natural aptamers also exist inriboswitches. Immunosensors are built by means of the appropriate combination of the biomolecules with the transducer used together, they can be applied in specific analytical situations. Immunosensors commonly rely on the reuse of the same receptor surface for many measurements. A Biochip is a combination of minute DNA spots hooked up to a hard surface. Scientists use DNA Biochips to check the expression levels of huge number of genes at the same time. Each DNA spot contains picomoles of a precised DNA sequence known as a probe. These can be tiny section of a gene or a DNA particle that are used to cross breed a cDNA or cRNA.

Photonic Sensing focuses on experimental contributions related to novel principles, and structures or materials for photonic sensors. Optical fibers can be used as sensors to measure strain, temperature, pressure and other quantities by modifying a fiber so that the quantity to be measured modulates the intensity, phase, polarization and wavelength or transit time of light in the fiber. Sensors that vary the intensity of light are the simplest, since only a simple source and detector are required. A particularly useful feature of intrinsic optical fiber sensors is that they can, if required, provide distributed sensing over very large distances. Photonic integrated circuits (PICs) are optically active integrated semiconductor photonic devices which consist of at least two different functional blocks, (gain region and a grating based mirror in a laser...).

A gas Sensor is a device that detects the presence of gases in an area, often as part of a safety system. This type of equipment is used to detect a gas leak and interface with a control system so a process can be automatically shut down. A gas detector can sound an alarm to operators in the area where the leak is occurring, giving them the opportunity to leave. This type of device is important because there are many gases that can be harmful to organic life, such as humans or animals. Metal oxide-based resistive-type gas sensors are solid-state devices which are widely used in a number of applications from health and safety to energy efficiency and emission control. Nanomaterials such as nanowires, nanorods, and nanoparticles have dominated the research focus in this field due to their large number of surface sites facilitating surface reactions.

Nanolithography is the art and science of etching, writing, or printing at the microscopic level, where the dimensions of characters are on the order of nanometers (units of 10 -9meter, or millionths of a millimeter). This includes various methods of modifying semiconductor chips at the atom ic level for the purpose of fabricating integrated circuits. Nanophotonics is the new emerging paradigm where light interacts with nano-scaled structures and brings forth the mysterious world to research.The combination of Photonics and Nanotechnology giving birth to “Nanophotonics” compliments and benefits each other in terms of new functions, materials, fabrication processes and applications.

Nanobiosensor is one type of biosensor made up with usage of nanomaterials i.e., nanoparticles and nanostructures. Because of the nanomaterials’ unique properties such as good conductivity, and physicochemical, electrochemical, optical, magnetic and mechanical properties, Nanobiosensors are highly reliable and more sensitive in biosensing approaches over conventional sensors which is having various limitation in detection. Quantum dots, nanotubes, nanowires, magnetic and other nanoparticles enhance sensitivity and lower limit of detection by amplifying signals and providing novel signal transduction mechanisms enable detection of a very low level of food contaminants, pesticides, foodborne pathogens, toxins and plant metabolites. 

Bio-sensing technologies are of increasing importance in healthcare, agri-food, environmental and security sectors, and this is reflected in the continued growth of global markets for such technologies. Biomechanics is closely related to engineering, because it often uses traditional engineering sciences to analyze biological systems. Some simple applications of Newtonian mechanics and/or materials sciences can supply correct approximations to the mechanics of many biological systems. Reliable methodologies are needed for point and stand-off detection of chemical, biological, radiological, special nuclear and explosive (CBRNE) materials.

Bioengineering applications of smart materials can be divided into three categories: (1) implants and stents, such as bone plates and marrow needles; (2) surgical and dental instruments, devices, and fixtures, such as orthodontic fixtures and biopsy forceps; and (3) devices and instruments for medical checkups, such as ultrasonic devices. The applications of the first category require strict biocompatibility of a material because it is implanted in the body for long periods. Among many traditional materials, including metals, alloys, and ceramics, that are available commercially, only a limited number are currently used as prostheses or biomaterials in medicine and dentistry.