生物传感器与生物电子学

Cyclic and differential pulse voltammetric techniques were employed to determine salbutamol at a glassy carbon electrode modified with a graphene oxide and poly(O-nitrobenzoic acid). The modified electrode was characterized by [Fe(CN)6]3-/[Fe(CN)6]4- couple and show high catalytic activity towards the oxidation of SAL in PBS (pH 7.6). The effect of scan rate, pH and concentration of SAL were studied at the modified electrode where a radical change in the anodic peak current was observed. The important parameters such as electrode real surface area, electron-transfer number, the surface concentration of the electroactive species, detection and quantification limits were determined and calculated to be 0.485 cm2, 1, 3.51 × 10-8 mol/cm2, 56 and 188 nM, respectively. The modified electrode was achieved excellent reproducibility and good stability. In addition, there is no interference with the determination of SAL except ascorbic acid and p-nitrophenol. The sensitivity of the modified electrode shows acceptable recoveries in the detection of SAL in pharmaceutical formulations and a human urine sample.

With increase in potential for bioterrorism, there is a great demand to detect the bio agents in the atmosphere in a quick, reliable and accurate method. Biosensor is an analytical device which uses enzymes, immunosystems, tissues that converts biological response into electrical, thermal or optical signals. Biosensor is an efficient and cost effective device which is most widely used for various day to day applications. Biosensor consists of two components: first the “sensing element” and second is the “transducers”. Sensing element may be either enzymes, antibodies, DNA, tissues or whole cells which transduces the biochemical reaction into electrical signals. Basic advantage of biosensor is the use of nanomaterials, micro fluidics and transducer on a single chip. Biosensors have found its application in fermentation, food industry, diagnosis, imaging, DNA sequencing and biodefense. Development of nanotechnology leads to the development of macro and micro sensors which is small and sensitive.

A nitration by penta-hydrated bismuth (Bi(NO₃)₃.5H₂O) was carried out on two commercial molecules, methoxynaphthalene 1 and naphthalen-2-ol 2. The compounds produced from this organic synthesis (1.a, 1.b, 1.c and 2') as well as the starting molecules 1 and 2 have undergone a study on their antioxidant capacity, using two methods: electrochemical cyclic voltammetry CV and DPPH biologically. The experimental results of the two methods confirm that the antioxidant power of these aromatic molecules is canceled in the case of nitration or by replacement of the hydroxyl group (molecule 2) by the methoxy group (molecule 1).

The development of biological, chemical and medical research had been possible due to implementation of a variety of low-cost, high-performance microscale devices in the consumer electronics and automotive markets through Microelectromechanical systems (MEMS) technology. Despite having huge socio-economic impact, not many studies have been performed in MEMS technology in the area of plant science and technology. In this review, a few examples and applications of our microfluidic devices to overcome this issue. With the help of MEMS devices, multiple model plants can be grown under various biotic and abiotic stress conditions. Through this platform, root and shoot phenotypes along with plant-pathogen interactions at high throughput can be easily monitored. Additionally, this platform provides the base for simultaneous characterization of different genotypes at physiological, biochemical and molecular levels. Large scale use of nitrogen fertilizer has led to various adverse effects on the environment, including loss of biodiversity, pollution of water, reduced crop productivity, and global climate change. There are various microfluidic sensors available which can measure nitrate in soils and quantify nutrient uptake of plants from surrounding environments in a real-time manner. Through the techniques available to measure availability of plant nutrients in soils, it is possible to use fertilizers efficiently, thereby leading to advancement of sustainable agriculture and environment.

Enteric and diarrheal diseases are major causes of childhood illness and death in countries with developing economies. Each year, more than half a million kids under the age of five die from these diseases. Escherichia coli, E. coli, a water/foodborne pathogen, is one of the major sources of food poisoning which results in severe diarrhea at extremely low concentrations and therefore is very challenging to be detected. Using available technologies, which are mostly based on amplification of low concentration samples, to detect the presence of the bacterium takes several hours to days; thus, a fast and an accurate detection alternative is on demand over lab-based technologies. In this sense, emerging nanoscale bio-transistors enable quantitative detection mechanism based on electrochemical binding of circulating analytes to immobilize antibodies on the biodevice's active surface. The state of the art of the Bio Field Effect Transistors (BioFETs) for fast track and accurate detection of E. coli is the concern of this review paper which describes and compares the recent advancements in the field. Furthermore, implications for novel approaches to different configurations based on the sensing principles and corresponding parameters are elaborated and discussed in detail.

Microfluidics technology is growing field emerged late 1950. It became popular passing through different historical events, contributing to the inception and growth of the field. From the beginning of inkjets to current enormous medical and industrial applications. It focus on handling fluids in the micro, Nano, Pico even femto liter level through utilizing the physical properties they exhibit while miniaturized. According to our study class of materials are available for microfluidics device fabrication and there are factors to consider in application specific design and microfabrication. In microfabrication technique, we can implement lithography, laser induced selective etching, powder blasting and molding found for fabrication. The medical and research application of microfluidics devices includes Cardiovascular System, Respiratory system, Nervous System, Digestive+Excretory System, Endocrine System, Integumentary System, cell culturing and preparation of scaffolds, therapeutics, diagnostics and preventive system. Multiples channels of biomaterials, which is biocompatible platforms to regenerate and rehabilitate Physiological and pathological conditions of complex tissues and organs. The aim of this paper is to present a paper reviewing on material selection, microfluidics fabrication, medical application and suggesting future prospects of the fields and possible microfluidics device implementation in biomedical field.