Enzyme electrodes are biochemical transducers. They function by converting biochemical reactions into electrochemical processes. This functionality could potentially give rise to a new generation of implantable medical devices such as biofuel cells and biosensors. The main aim of this study was to fabricate and characterise enzyme electrodes for potential use in these applications. The approach involved testing various materials such as different types of enzyme, polymeric electron transfer mediators, enzyme entrapment materials, conductive supports and matrices and biocompatible polymers. Various enzyme immobilisation methods were used and various polymeric electron transfer mediators were fabricated and tested. The investigation was based primarily on electrochemical techniques. The materials and immobilisation techniques presented could potentially be used to improve future enzyme electrodes. This may be achieved through the novel use of biocompatible and biomimicking polymers, through simple biofuel cell fabrication and with the use of multi analyte biosensors developed during this investigation.
A microsomal membrane bound alcohol oxidase enzyme was isolated from a hydrocarbon degrading Aspergillus terreus fungus that could oxidize short chain-,long chain-, secondary-, and aryl-alcohol substrates. High aggregating property of the protein was demonstrated by AFM, DLS and TEM analyses. Chemical analysis showed the presence of oleic acid and palmitic acid at a ratio of 2:1 in the purified protein. We have demonstrated a highly efficient method for dissociation and simultaneous deflavination of the alcohol oxidase protein using ?-ME. The potential applications of this approach on preparing apoprotein and its reassemble with FAD to a functional enzyme are envisaged in the preparation of enzyme electrodes for biosensor and biofuel cell applications. The findings obtained through this investigation have revealed many interesting facts about this novel microsomal alcohol oxidase enzyme.This investigation has opened up new avenue on the research to explore the architecture of alcohol oxidase proteins from fungal sources including their structure-function relationship and potential applications.
Advancements in the micro/nano-fabrication techniques have opened up new avenues for the development of portable and easier-to-use biosensors. Over the last few years, carbon electrodes have been widely used as sensing units in biosensors due to their attractive physiochemical properties. This book details different strategies to develop functionalized high surface carbon micro/nano-electrodes for electrochemical and biosensing devices. Carbon electrodes were fabricated via carbon-MEMS technique, which is based on pyrolyzing prepatterned photoresist. To increase the surface area of the carbon electrodes, multiple approaches such as (i) fabrication of porous 3D carbon microarrays, (ii) conformal coating of graphene onto 3D carbon microarrays, and (iii) fabrication of controllable carbon nanostructures were investigated. For carbon surface functionalization to covalently attach biomolecules, different oxidation techniques and the resultant surface carbon–oxygen groups were analyzed and compared. Lastly, label-free detection of platelet-derived growth factor oncoprotein, a cancer biomarker, was demonstrated on 3D carbon microarrays platform with sub-nanomolar detection limit.
Biosensor employing organelles in immobilized form are widely used in environmental monitoring. These immobilized organelles play vital role in sensitivity, accuracy, and stability of the biosensor system. Some of the organelle used for immobilization is whole cell, protein, enzyme and DNA. Traditionally biosensor used whole cell from one individual strain of microorganism. This concept limits the biosensor detection to certain specific samples alone. Detection of the content of the samples depends on the properties of the immobilized microbial cell. For detection of broad range of samples, novel biosenor using mixed microbial cultures is being designed in this dissertation.
The combination of biological molecules and CNTs is of great importance in developing miniaturized sensor devices for future clinical diagnostic and electronics applications. Biosensing technology using aligned CNTs solely depends upon amplified signals generated by biomolecular interactions. Aligned CNTs have huge potential as electrochemical sensors as they provide enhanced electron transfer in redox reactions due to high length to diameter (aspect ratio). CNT based functional devices including transistors, sensor, emitters and energy units require vertically aligned CNTs with a high length to diameter aspect ratio and their ability to mediate electron transfer reactions of electroactive species in solution when used as electrode material. Carbon nanotubes have been proved as better electrode materials than traditional carbon electrodes, clay nanoparticles and conducting polymers etc. due to their proficient charge transfer capability and high chemical stability. Major Aim of this book is to present clear idea to the readers who intend to devise a highly sensitive and efficient vertically aligned CNT based electrochemical sensors.
This book illustrate the study and development of bioactive electrodes to apply in piezoelectric sensors for biomedical applications, respectively in internal orthopedic prosthesis. These electrodes are composed by Titanium doped with Silver and Gold. Titanium, being widely known for its biocompatibility, serves as electrical conductor, Silver acts as antibacterial agent and Gold is used to induce Silver ionization due to the formation of a galvanic pair, once the antibacterial effect is achieved by Silver ions. These electrodes were deposited on piezoelectric polymer, assembling a sensor capable of detecting anomalies, in real time, related to the implementation of prosthetic devices inside the human body. The objective is to produce biocompatible and antibacterial electrodes without compromising the electrical conductivity. Along the literature the reader can find a state of the art related to this matter as well as the main results of the physical, chemical, electrical and structural characterization performed in this study.
Metallic starch capped gold nanoparticles have been synthesized by the reduction of chloroaurate anions [AuCl4]- solution with hydrazine in the aqueous starch and ethylene glycol solution at room temperature and at atmospheric pressure. The characterization of synthesized gold nanoparticles by UV–Vis spectroscopy, Scanning electron microscopy (SEM), X-ray diffraction (XRD) indicate that average size of pure gold NPs is 5-10 nm, they are spherical in shape and are pure metallic gold. Starch capped gold nanoparticles along with tyrosinase enzyme are effectively entrapped within sol-gel matrix for application in catechol biosensor. Enzymatic reaction between tyrosinase and catechol results in the formation of a colored compound which shows characteristic absorbance at 410 nm. Starch@AuNPs based catechol biosensor showed fast response with linearity for catechol sensing from 1 to 5 mM. Effect of buffer pH and its concentration was also studied and results showed drastic changes in absorption intensity with pH and concentration variation. Along with catechol biosensor, starch capped gold NPs find their application in glucose, urease and peroxide biosensor, owing to their stability.
The development of fuel cells over the last century has been heavily influenced by external factors. Initially, fuel cells were seen as an attractive means for the generation of power because the efficiencies of other technologies were very poor. However, as the efficiency of these other technologies rapidly improved, the interest in fuel cells faded. Then, in 1950’s fuel cells were rapidly developed for application in space. More recently, significant technical progress in fuel cell technology has made fuel cells appear more viable than ever for a variety of applications. Additionally, concerns about renewable energy resources and the environment have increased interests in generating power with even higher efficiencies and lower emissions, and this has also raised the interest in fuel cells. Although some interesting work was done on fuel cells during the first half of the 20th century, Sir Francis Bacon began his historical work on fuel cells in 1933 and developed a hydrogen-oxygen cell that operated at moderate temperatures using alkaline.
Biomass is biodegradable, less CO2, CO, H2S, HC and NOX emissions as well as renewable energy resource for the creation of steam and electricity, transportation fuel, manufacturing industries as well as a solvent in the laboratory. Agricultural crops residues (biomass) have emerged as one of the promising sources for bioethanol production. Such an approach can contribute to solve major problems of air pollution resulting from green house gas emission evolution and future crisis due to the shortage of energy sources. The controlling factors that affect the production of bio-fuel (biodiesel and bioethanol) from biomass are described. The optimal value of the parameters such as temperature, pH, yeast and enzyme percent and fermentation period are found and explained. Different types of fuel cell and electricity generation were explained from different scientific sources. Nowadays biofuel as well as biofuel cell is an innovative and important energy source from biomass by which power can be generated both in transportation and electricity. Still no research work done in this regard except few demonstration. That is why, the scope of innovative bio-fuel cell for electricity generation.
The exploration of biomass fuels encourages the reduction of world atmosphere pollution and global warming. In addition, the depletion of nonrenewable energy sources such as fossil fuels induces the developing technologies to harness new and renewable energy sources. Abundant of fruits waste can be reused for the bioethanol production. Hence, it can reduce pollution and waste material, thus helps in waste disposal management. In this research, nine parameters were studied that could affect the bioethanol production from mango waste. It was found that the bioethanol production was the highest at temperature of 30 0C and pH 5. Similarly, the highest ethanol concentration was obtained when 3 g/l of yeast used for fermentation. S. cerevisiae yeast was recognized as the best ethanol-producing strain. The bioethanol concentration was highest when the mango mash was hydrolyzed with pectinase enzyme, followed by hydrolysis using cellulase enzyme. It was found that the content of metal elements and viscosity in the bioethanol were under ASTM standard. Therefore, the bioethanol produced from mango waste was suitable to be used as engine fuel and environmetl pollution can be reduced.
The new design of an Impedance measurement based sensor is integrated into the standard 96 wells microtiter plate which is use for characterizing different stimulus hydrogels. The online monitoring of swelling and deswelling of hydrogel is possible with this new system. Hydrogels of Poly-Hydroxyethyle Methacrylate, Poly (HEMA) with different compositions of mixing monomers were used for measurements. These hydrogels which absorbs/desorbs solution in response to changes in surrounding environmental condition polymerized over the sensor with roughly 200µm height. The sensor output voltage response to pH value changes with swelling and contracting of hydrogel. The shift in the resistivity of hydrogel was investigated as function of different mixing monomers ratios and compartment of hydrogel. It was found the concentration of cross-link and water content play significant role in changing resistivity of hydrogel. An additional advantage with new setup its use only 200µl of solution and 200µm thick hydrogel layer in standard 96 wells microtiter plate for characterizing hydrogels.
Heroine is synthetic derivative of morphine, a naturally occurring substance extracted from unripe seeds or capsules of Papaver somniferum (poppy plant). The use of heroine and morphine as a recreational drug has reached epidemic proportion, largely because of increased availability. The currently used techniques for the detection of opiate drugs are time consuming, expensive and not amenable to on-site application. This book describes about development of a highly sensitive, fast, reliable, field applicable and cost effective immunoassay/ immunobiosensor for the detection of opiate drugs: morphine and heroin, the most addictive and commonly abused narcotics. Various types of immunoassay are described in this book using enzyme, fluorophore, carbon nanotubes, gold nanoparticles and phage display detection which shows detection limit in the ppb range without the aid of any sophisticated instrument.
Biosensors are nowadays a powerful tool to enable the detection of specific biological interactions and to evaluate the concentration dependence in the response. A biosensor usually consists of three different parts: the sample to be measured, the transducer and the electronic system that amplifies the signal, analyzes the data and brings a result to the final user. When the analyte interacts with the bioreceptor, the transducer sends a signal that is processed by the electronics. All this process occurs in a efficient, quick, cheap, simple and specific way. Optical biosensors are the most powerful ones for investigating processes at the solid/liquid interface. Among them the grating coupler is immune to electromagnetic interferences, pushes the sensitivity to levels even higher than other techniques and allows for the direct monitoring of macromolecular adsorption. Taking advantage of the last advances in nanotechnology, this book studies the versatility of an Optical Grating Coupler Biosensor. The design of new grating sensor chips is investigated, a new calibration technique for the sensors is proposed and different biomedical scenarios are tested.
It gives me a great pleasure to bring out this book titled "Enzyme Applications in Textile Processing & Finishing". The applications of enzyme in textile materials plays important role in making the environment Eco friendly. Author believes this book will provide a platform to the students and researchers in under graduate and post graduate level. The aim of the author is therefore to bring fundamentals of the subject right down to the level of the average student and basic researches in the field of textile processing. The author would like to express his gratitude towards his mother, wife and members of his family for their kind co-operation and encouragement which helped in completion of this project.
The concern about global warming effects by continuous exploitation of non renewable fossil fuels and scarcity of electricity generation accelerates the urge for searching alternative source of energy. Development of Microbial fuel cell using microbes present in waste water is the novel approach to treat this hurdle. Apart from biopower generation, it acts as a biosensor. Microbes metabolizes the organic matter present in waste water during the process electricity is generated. Within course of time the wastewater is treated with Chlorella vulgaris for the removal of phosphate for about 50 percent present in water. The amount of electricity generated has increased. The biomass thus produced, can be used for biofuel generation. For further purification of this treated wastewater, a novel method of treating it with Strychnos potatorum (chilla ginjalu) seeds is attempted.