Single Laboratory Experiment Integrating the Synthesis, Optical Characterization, and Nanocatalytic Assessment of Gold Nanoparticles

Abstract

We report on a simple, rapid, and room-temperature undergraduate-level experiment for gold nanoparticle synthesis, analysis, and utilization as a catalyst for the sodium-borohydride-assisted reduction of methylene blue and Congo red dyes. Typical procedures toward gold nanoparticle formation require an elaborate, lengthy synthesis (some requiring 1 h for completion of nanoparticle formation and ripening), whereas faster methods frequently yield inhomogeneous or catalytically inferior gold nanoparticles. This situation limits the usefulness of gold nanoparticles as rudimentary nanochemistry teaching tools in time-restricted undergraduate laboratories. The rapid gold nanoparticle synthesis presented herein utilizes ascorbic acid or sodium borohydride as dual reducing/capping agents to produce catalytically active gold nanoparticles at the “speed of mixing” under ambient conditions, allowing preparation and characterization to be performed within a single laboratory period. Furthermore, whereas most gold nanoparticle syntheses require rigorously cleaned glassware to avoid contamination and irreproducibility, the devised undergraduate experiment reported here alleviates this burden by employing disposable reaction vessels. Thus, this undergraduate-level laboratory experiment is designed to provide a meaningful introduction to metal nanoparticle synthesis and application while simultaneously being accommodated by a typical 2–4 h laboratory period, providing much-needed teaching assistance in the growing field of nanomaterials education.

Open Inquiry-Based Laboratory Project on Plant-Mediated Green Synthesis of Metal Nanoparticles and Their Potential Applications

“…Antioxidant, antibacterial, and antifungal properties of NPs may be included. Several laboratory experiments involving nanoparticles have been published ,,,,− which may be valuable to instructors in adapting the learning strategy to their class. In addition, conducting research for the first time can be intimidating for both young (undergraduate) and older (postgraduate) students, so this course can serve as a preparatory module to help students overcome some of the difficulties and challenges in translating research knowledge into practice, which is useful for pedagogical design and research evaluation.…”

“…As nanotechnology is an ongoing interest, several laboratory experiments and inquiry-based approaches related to nanoparticle synthesis, characterization, and their potential applications have been reported. − Unfortunately, the chemical method is the most widely utilized route for nanoparticle formation, where the use of hazardous substances in the chemical reduction and stabilizing process is required. Replacing harmful chemicals with natural resources such as plant extracts may prove to be an attractive alternative and environmentally friendly approach.…”

Mimicking Stained Glass: A Hands-On Activity for the Preparation and Characterization of Silica Films Colored with Noble Metal Ions and Nanoparticles

“…Colored glass thus represents a highly interdisciplinary and engaging topic to demonstrate in a tangible way the chemistry of color in solid materials and the optical properties of nanomaterials. However, while the literature abounds with demonstrations and activities regarding the synthesis and optical characterization of noble metal nanoparticles dispersed in a liquid phase − or embedded in a polymer matrix, , there are no laboratory activities dedicated to colored and stained glass due to the high temperature, lengthy procedures, and safety issues involved in glass production.…”

Teaching Nanotechnology through Research Proposals

“…Nanotechnology, with its multidisciplinary character, has experienced a rise in the past few decades and has had a significant influence on almost all fields of science and technology, − including chemistry . This was also recognized in 2016 when the Nobel Prize in Chemistry was awarded to Stoddart, Sauvage, and Feringa for their remarkable work on nanomachines. , As the relevance of nanotechnology in society grew more and more obvious, its importance in education became more evident too. ,− This has been recognized at all levels of education, namely, primary, secondary, ,− and tertiary (higher) education. ,− Most contributions regarding nanotechnology in higher education, however, deal with the importance of teaching nanotechnology, , the content taught within nanotechnology courses ,,, or laboratory experiments found useful to illustrate important concepts in nanotechnology in the lab. − However, there are only several published contributions on the activities in the nanotechnology classroom ,,,,,,, at any level as most contributions focus on wh...…”