CONICET | Buscador de Institutos y Recursos Humanos

Nanomaterial-Assisted Signal Enhancement of Hybridization for DNA Biosensors: A Review  Sustainability of agricultural systems has become an important issue all over the world. Many of the issues of sustainability are related to the quality of soil and the changes through time. Intensive cultivation leads to a rapid decline in organic matter and in nutrient levels besides affecting physical and biologycal properties of soil. Phosphorus (P) is an essential plant nutrient that must be added to most soils to maintain plant growth and sustain crop yields. Organic phosphorus compounds in soil can constitute 30 50 % of total phosphorus. The assimilation of this phosphorus by plants and microorganisms is preceded by soil enzymes. Phosphatases enzymes play a major role in the processes of mineralization (dephosphorylation) of organic P substrates. Enzyme activities are indicators of soil quality because: i) they are strongly connected with important soil properties such as organic matter, physical properties and microbial activity or biomass; ii) they respond earlier than other soil properties; and iii) they involve relatively simple methods compared to other soil quality bioindicators. In the present study we propose a precise and accurate method to determine the alkaline and acid phosphatase activity in soil using adenosine monophosphate, wich is a natural compound, as a substrate. The adenosine released by the enzymatic reaction was cuantified by MEKC method. The background electrolyte consisted in 20 mM phosphate buffer (pH 8) 10 mM sodium dodecyl sulphate and 10% acetonitrile. The LOD and LOQ were 2.27 10-4 and 6.4 10-4 mg mL-1, respectively. The values for the activities of alkaline and acid phosphatase were 44.5±3.5 and 21.7±2.3 µmol of free adenosine g-1 h-1 respectively. These are the first studies on the determination of the activity of alkaline and acid phosphatase using MEKC. The CE method has demonstrated to be reliable to evaluate enzymatic activity, representing a suitable and convenient alternative to the spectrophotometric method. The most important advantage of MEKC is that it allows the use of natural substrate in the enzymatic activity. Moreover, compared to LC methods, capillary electrophoresis methods have some advantages. One of them is using a smaller volume of samples, and also producing less amount of waste, which is a very important point in this time of the Green Analytical Chemistry (GAC).

enviar mensaje