Diseño de un instrumento portátil para aplicaciones ambientales por mediciones amperométricas sobre material biológico

El instrumento portátil optimizado para las medidas  de amperometria, en el monitoreo de  materiales bioactivos ha sido diseñado, fabricado y probado. Expresamente ha sido diseñado, para funcionar con una amplia gama de bio-muestras foto-activas. La cámara  de medición del instrumento; destaca dos tipos de fuentes ópticas para detectar la actividad fotosintética de plantas (p. ej. spinacia oleracea) y microorganismos (p. ej. algas y cyanobacteria). En la cámara son inseridos los electrodos serigrafiados para medir la corriente fotogenerada, ademas cuenta con un sistema de flujo para el transporte del electrólito. La transferencia fotosintética de electrones, es activada por dos LEDs (470nm y 660nm de emisión), para permitir varias longitudes de onda de excitación para utilizarlos con diversos materiales biológicos. El objetivo de la aplicacion, es en campos como agroalimentario, farmacéutico y biomédico. Este Artículo describe algunas de las posibles aplicaciones ambientales ABSTRACT A portable instrument performing amperometric measurements for monitoring bioactive materials has been designed, manufactured and tested. It has been specifically designed to operate with a wide range of photoactive biosamples. The sensing chamber in the instrument features two different optical sources to detect the photosynthetical activity of plants (i.e. spinacia oleracea) and microorganisms (i.e. algae and cyanobacteria). The chamber is provided with screen-printed electrodes to measure the photogenerated current and with a fluidic system for the electrolyte transport. Photosynthetic electron transfer is activated by two LEDs (470nm and 660nm emission) in order to enable various excitation wavelengths and match several different biological materials. Target applications belong to the agro-food, pharmaceutical and biomedical fields. This paper describes some possible environmental application

Photosynthesis at the forefront of a sustainable life

The development of a sustainable bio-based economy has drawn much attention in recent years, and research to find smart solutions to the many inherent challenges has intensified. In nature, perhaps the best example of an authentic sustainable system is oxygenic photosynthesis. The biochemistry of this intricate process is empowered by solar radiation influx and performed by hierarchically organized complexes composed by photoreceptors, inorganic catalysts, and enzymes which define specific niches for optimizing light-to-energy conversion. The success of this process relies on its capability to exploit the almost inexhaustible reservoirs of sunlight, water, and carbon dioxide to transform photonic energy into chemical energy such as stored in adenosine triphosphate. Oxygenic photosynthesis is responsible for most of the oxygen, fossil fuels, and biomass on our planet. So, even after a few billion years of evolution, this process unceasingly supports life on earth, and probably soon also in outer-space, and inspires the development of enabling technologies for a sustainable global economy and ecosystem. The following review covers some of the major milestones reached in photosynthesis research, each reflecting lasting routes of innovation in agriculture, environmental protection, and clean energy production

Towards an integrated biosensor array for simultaneous and rapid multi-analysis of endocrine disrupting chemicals

In this paper we propose the construction and application of a portable multi-purpose biosensor array for the simultaneous detection of a wide range of endocrine disruptor chemicals (EDCs), based on the recognition operated by various enzymes and microorganisms. The developed biosensor combines both electrochemical and optical transduction systems, in order to increase the number of chemical species which can be monitored. Considering to the maximum residue level (MRL) of contaminants established by the European Commission, the biosensor system was able to detect most of the chemicals analysed with very high sensitivity. In particular, atrazine and diuron were detected with a limit of detection of 0.5 nM, with an RSD% less than 5%; paraoxon and chlorpyrifos were revealed with a detection of 5 mu M and 4.5 mu M, respectively, with an RSD% less than 6%; catechol and bisphenol A were identified with a limit of detection of 1 mu M and 35 mu M respectively, with an RSD% less than 5%

Sensing photosynthetic herbicides in an electrochemical flow cell

Specific inhibitory reactions of herbicides with photosynthetic reaction centers bound to working electrodes were monitored in a conventional electrochemical cell and a newly designed microfluidic electrochemical flow cell. In both cases, the bacterial reaction centers were bound to a transparent conductive metal oxide, indium-tin-oxide, electrode through carbon nanotubes. In the conventional cell, photocurrent densities of up to a few muA/cm2 could be measured routinely. The photocurrent could be blocked by the photosynthetic inhibitor terbutryn (I 50 = 0.38 +/- 0.14 muM) and o-phenanthroline (I 50 = 63.9 +/- 12.2 muM). The microfluidic flow cell device enabled us to reduce the sample volume and to simplify the electrode arrangement. The useful area of the electrodes remained the same (ca. 2 cm2), similar to the classical electrochemical cell; however, the size of the cell was reduced considerably. The microfluidic flow control enabled us monitoring in real time the binding/unbinding of the inhibitor and cofactor molecules at the secondary quinone site