The effect of green chemistry education based on practical activity on learning and attitude of pre-service chemistry teachers

Background and Objective:Chemistry plays a fundamental role in human civilization and its place in economics, politics and life is becoming more and more prominent and covers a wide range of chemical products such as drugs, dyes, fertilizers, etc. However, the environmental damage caused by it is a major human concern. Many of us today take steps to reduce environmental impact, for example by participating in chemical recycling programs and using energy-saving light bulbs; we buy local products and maybe drive hybrid cars. But what if "we could somehow prevent pollution from the start?" Thus, with a new approach called green chemistry, chemists are being led to a new phase of research activities to develop green reactions and use them instead of the old methods, to help human health and society by eliminating toxins from chemical processes. The purpose of this research is education of green chemistry through the curriculum related to the principles of green chemistry in General Chemistry Lab 1and the effect of this educational course on learning and attitude of the pre-service chemistry teachers toward green chemistry principles. Methods: This educational course involves two green experiments implemented according to green chemistry principles. The experiments include determination of molar mass relation in a chemical reaction and determination of the amount of ascorbic acid in a tablet of vitamin C. The research methods are practical, experimental and quasi-experimental and the used instruments were the researcher-constructed tests in the field of learning and attitude domain. Statistic population of this study consists of experimental group (N=30) and control group (N=30) of the student teachers at Shahid Rajaee Teacher Training University in the academic year 2017-2018. Data analysis was done using descriptive and inferential statistics with SPSS software. Findings: The obtained results show that among12 principles of Green Chemistry, students have learned the principles of 1 to 4 and 7 to 12 of these 12 principles and they have been attracted to them. In addition, the implementation of a curriculum related to the principles of green chemistry has had a positive impact on the attitude of the pre-service chemistry teachers. Conclusion: Findings from the research show that teaching the principles of green chemistry can be done based on the activity-oriented approach in the chemistry curriculum as in most developed countries. Student-teacher education can lead them to develop a positive attitude towards green chemistry and to have more motivation and desire to study chemistry based on the principles of green chemistry and to pass this attitude on to their students in the teaching process. Also, in designing the curriculum, it should be noted that in the sequence of practical activities, it should be done in such a way that it includes all the principles of green chemistry so that education based on it can give all the principles of green chemistry to learners or give them a positive attitude.   ===================================================================================== COPYRIGHTS  ©2019 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

High electrochemical detection of dopamine based on Cu doped single phase hexagonally ZnO plates

Dopamine is a chemical that plays a key role in various neurological diseases such as Parkinson's, depression, and some types of cancer. Hence, sensitive detection methods of dopamine are necessary for early discernment of diseases related to abnormal levels. In this study, Cu doped ZnO (Cu/ZnO) nanostructures, immobilized onto the surface of glassy carbon electrode (GCE), have been investigated as a highly efficient electrode material for the electrochemical detection of dopamine (DA). A simple hydrothermal process was used for the synthesis of the ZnO and Cu/ZnO nanostructures. Detailed characterization revealed that addition of Cu on the ZnO changed the morphology of ZnO creating a highly microporous nanostructure. The electrochemical response of DA on the Cu/ZnO/GC electrodes, determined using cyclic voltammetry (CV) and differential pulsed voltammetry (DPV), indicated that on these materials it is possible to achieve lower over-potentials for the DA oxidation and higher catalytic activity. Furthermore, the GCE modified with 50 % Cu doped ZnO showed the most promising performance with high stability in wide range of pH values (2–8 pH), and linear response for DA from 0.1–20 μM with high sensitivity of 2630 nA/μM and detection limit as low as 55 nM. The analytical performance of the developed sensor showed its potential capability for the DA quantification in complex biological systems