Discovering Nanoscience

Abstract

Exploring Gold Nanoparticles, the IBI Prize-winning module, guides students' construction and evidence-based refi nement of their personal models of gold nanoparticles.T he President's Council of Advisors on Science and Technology stresses the importance of adoption of empirically validated instructional practices, such as inquirybased laboratory experiences, in higher education (1). The Exploring Gold Nanoparticles laboratory module employs an inquiry-based instructional tool called the Model-ObserveRefl ect-Explain (MORE) Thinking Frame (2) to support student construction of evidencebased models of nanoparticles in introductory chemistry courses. Using MORE has been shown to enhance students' understanding of the nature of science and of scientific models compared with traditional teaching methods (3,4).The MORE Thinking Frame scaffolds students' thinking as they work to construct and evaluate evidence-based, molecular and/or nano-level models of chemical systems. A MORE module begins with a written, prelaboratory assignment (5) that prompts each student to describe his or her ideas about the system under study from macroscopic and molecular-level perspectives. This serves as the student's initial model. In writing their models, students are encouraged to refl ect upon and articulate their own ideas, rather than to look up scientists' ideas. Next students conduct experiments in the laboratory (observe) and are explicitly prompted to refl ect upon the implications of their observations as they relate to their initial model ideas. Students then refi ne their models and explain how their revised molecular-level ideas are consistent with the experimental evidence they collected.After completing an iteration of MORE, students apply MORE to a subsequent set of laboratory activities, which provides additional opportunities for them to refi ne their models. Each student presents a refined model, explains why it has (or has not) changed from his or her previous model, and proposes a generalized model that could be used to understand new situations. At the end of a module, each student proposes a next experiment that would help further refi ne or test his or her molecular-level model.Although the MORE Thinking Frame is well-suited to guide students' thinking as they conduct original research, in our general chemistry laboratory course, we have more often applied it to investigations for which there is a fundamental, scientifi cally accepted model that has not yet been presented to students. Research has shown that instructional paradigms in which students fi rst work to develop general rules or models, and expert ideas are presented only after students complete their investigations, promote deep understandings that facilitate transfer of learning [e.g., (6)]. Research in the context of another MORE module (7) indicates that student engagement in three thinking processes is strongly correlated with subsequent successful reasoning in new contexts. These include (i) constructing molecularlevel models that are consistent wi...

Differential effects of amino acid surface decoration on the anticancer efficacy of selenium nanoparticles

“…Some researchers have investigated the interaction between amino acids and nanoparticles. 34,35 For instance, Yu and coworkers pointed out that the peptide binding process in the fabrication of gold nanostructures should be considered a three-step sequence, which is highly dependent on amino acid composition and sequence. 36 Among them, fewer studies have been focused on the differential effects of amino acid on the biological applications of SeNPs.…”

Recent advance in laser-induced chemical reactions investigated by <italic>in-situ</italic> Raman spectroscopy

“…当入射 电磁场(光子或电子)的频率与金属纳米颗粒表面自 由电子的振荡频率匹配时, 即产生LSPR效应 [7~10] . 随 着近年来纳米技术的发展和理论模拟手段的日益丰 富, 对表面等离激元(surface plasmon, SP)的理论研究 也逐步深入, 形成了一门新的学科--表面等离激元 学 [11,12] . 值得注意的是, 尽管研究最为广泛的是IB族元 素(Cu、Ag和Au)的LSPR效应, 但这种现象并不只局 限于IB族元素.…”

Ultrafine Mn3O4Nanowires/Three-Dimensional Graphene/Single-Walled Carbon Nanotube Composites: Superior Electrocatalysts for Oxygen Reduction and Enhanced Mg/Air Batteries

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