MSc student bridges the fields of chemistry and physics

Ané Kritzinger, a master’s student in the Department of Chemistry, is bridging the fields of chemistry and physics to develop an ultra-sensitive instrument for pollutant detection. 

She works with optical tweezers that use tightly focused light to trap and manipulate microscopic particles and quantum dots semiconducting nanocrystals with attractive optical properties that make them suitable as analytical sensors. Her innovative research investigates the possibility of combining optical tweezers with fluorescence spectroscopy of quantum dots for pollutant detection.

Ané is supervised by Professor Patricia Forbes, whose research focuses on environmental monitoring and sensing. The optical tweezer setup is in the Structured Light Laboratory of her co-supervisor, Prof Andrew Forbes, at the University of the Witwatersrand.

Ané, who was awarded the James Moir medal from the South African Chemical Institute in 2020 for her academic achievements at honours level, has recently won prizes at national conferences in the chemistry and physics fields, where she presented her interdisciplinary MSc research. She received the award for the best MSc presentation in photonics at the annual conference of the South African Institute of Physics and was the runner-up for the best MSc flash talk at the South African Chemical Institute’s Young Chemists’ Symposium. Ané was also recently featured as a prestigious Trust Science Champion.

Ané noted that “even though these conferences were virtual, I got to know other people in my field, hear about the latest research in the country and improve my presentation skills. It was also great to have our work recognised by both the physics and chemistry communities.” 

She is seeing the benefits of collaborating with other disciplines, and she said, “it allows your research to reach a wider audience, results in more innovative solutions and inspires you to confront questions that may not otherwise occur to you.”

Researchers

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  Prof Patricia Forbes

  Professor Patricia Forbes completed her undergraduate studies at the University of Natal in Durban (now the University of KwaZulu-Natal), and obtained an MSc from the University of Cape Town and a PhD from the University of Pretoria (UP), which she joined in 2009. She was previously employed as Environmental Manager at Impala Platinum refineries and as Head of the Air Quality Research Laboratory at the Council for Industrial and Scientific Research.

  Environmental analytical chemistry researchers push the boundaries of analytical science to improve environmental and human health, and thereby our quality of life. 

  Prof Forbes leads UP’s Environmental Monitoring and Sensing Research Group in the Department of Chemistry and holds the Rand Water Research Chair. The research group focuses on developing new ways to monitor environmental pollution, particularly emerging chemical pollutants in water and organic air pollutants such as polycyclic aromatic hydrocarbons and pesticides. The analytical techniques they employ include gas and liquid chromatography and mass spectrometric detection, as well as denuder-based systems to monitor gas and particle phase air pollutants, bio-monitors like lichen to detect air pollution and novel fluorescence sensor screening methods based on engineered novel nanomaterials.

  In terms of cross-faculty research, Prof Forbes is working with Maggi Loubser of UP’s Department of Tangible Heritage Conservation in the Faculty of Humanities to assess pesticide levels in museum collections. This is important for the safety of those who access these collections, as some pesticides that have historically been used in museums to preserve artefacts can be harmful to human health.

  Prof Forbes has also collaborated with the Faculty of Veterinary Science to better understand the calcium requirements of crocodiles bred in captivity; with the Faculty of Health Sciences on a project regarding water quality; and the Faculty of Engineering on an air and water pollution project.

  A recent highlight is her appointment by the Minister of the Department of Forestry, Fisheries and the Environment to a panel of experts that will provide an advisory service in the establishment and review of air quality standards for South Africa. Prof Forbes regards this as a milestone as it is evidence of the quality and relevance of her research; the five-year appointment also provides her with an opportunity to have an impact on policy and future developments in air pollution control.

  Another highlight for the professor is the research group’s recent publication in highly acclaimed journal Nature Photonics, the result of a collaboration with the School of Physics at the University of the Witwatersrand. The group built an all-optical system to trap and control particles that can detect water pollutants at extremely low concentrations, even in tiny volumes. Prof Forbes says this work signals a move towards light-driven, “chemistry-on-a-chip” approaches to sample analysis.

  Prof Forbes says she is inspired by Prof Graham Cooks, a Distinguished Professor of Chemistry at the Aston Laboratories for Mass Spectrometry at Purdue University in the US. Prof Cooks, who’s originally from South Africa, has had remarkable success in his research, having achieved an H-index of 141. Prof Forbes has met Prof Cooks on several occasions in South Africa when he delivered plenary lectures at local analytical chemistry conferences, and says she relates to his approach to research in analytical chemistry as they are both looking to find sustainable, cost-effective means of analysis. She adds that he is an incredibly humble and approachable person regardless of his acclaim and stature as a leading analytical chemist.

  Prof Forbes hopes to have further impact in the realms of government, industry and academia. She says that the research capabilities and expertise that she has established and developed position her well to address several topical environmental monitoring challenges of global relevance, and she plans to continue developing analytical tools to answer questions that cannot be answered without these technologies.

  Her advice to school learners or undergraduates who are interested in her field is to stay curious and not be afraid of asking questions.

  For recreation, she loves running.

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