Dual sensing for highly specific and quantitative chemical analysis in pesticides detection

• Applicant: Professorin Dr.-Ing. Olfa Kanoun
• Subject Area: Analytical Chemistry ; Measurement Systems
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 449639277

Pesticides are among challenging contaminants found in water, food, and soil since they are accumulating in the environment posing a serious risk to human health. The gold standard approaches of analytical chemistry detection are costly and laborious. Electrochemical methods (EC), such as e.g. impedance spectroscopy and voltammetric methods, are inexpensive and quantitative, widely used in analytical chemistry, but they typically have a poor selectivity. Surface-enhanced Raman spectroscopy (SERS) is highly sensitive and detects chemical "fingerprints" of molecules, but it faces critical challenges when it comes to making quantitative analyses. Combining the two measurement principles in one measurement method provides the possibility to obtain more specific and quantifiable information about complex analytes, to improve sensitivity and to realize synergy effects. Nevertheless, it involves some challenges due to the expected dependence of the two methods. Electrical potential affects surface properties, ion concentration and charge transfer between analytes and affect thereby also the SERS enhancement. The photo-induced effects, such as photocatalytic reactions on plasmonic surfaces, can create new products offering new possibilities to obtain additional information on the complex mixtures by analyzing these products electrochemically. This project aims to study the combination of EC methods with SERS for the ultrasensitive label-free detection of analytes in complex mixtures. It aims to answer in deepness fundamental questions, which this dual-sensing approach opens, concerning feasibility, configuration, specificity prospective and quantification limits and to identify synergy and mutual influences in the case of pesticide detection. The acquired knowledge is to build the basis for novel and cost-effective portable, highly specific and ultrasensitive sensor systems.

• DFG Programme: Research Grants
• International Connection: Russia
• Partner Organisation: Russian Foundation for Basic Research, until 3/2022
• Cooperation Partner: Professorin Dr. Evgeniya Sheremet, until 3/2022