Integrating liquid chromatography-electrochemical detection-surface Enhanced Raman Spectroscopy on microfluidic chip for phenylurea herbicides analysis

The widespread use of phenylurea herbicides (PHs) is a serious threat to human health and environmental safety. These pollutants usually have similar molecular structures but distinct toxicities. Therefore, developing rapid detection methods to analyze PHs quantitatively and qualitatively is highly desirable. This study fabricated a microfluidic glass liquid chromatography (LC) coupled with electrochemical detection (ECD) and Surface-Enhanced Raman spectroscopy (SERS) synchronous system, which demonstrated excellent separation and analysis performance for PHs. The complete separation of three PHs could be achieved using the microfluidic chip LC with a theoretical plate number of 342525 plates m–1. The limit of detection (LOD) of the PHs for optimized electrochemical analysis reached 0.0099–0.1388 mmol/L. More importantly, the detection system integrated with ECD and SERS had high sensitivity and molecular recognition ability, with intra and inter-day precision of less than 6.7630% and 7.5601%, respectively. The recovery of the PHs could reach 102.9861% when this detection system was applied to the analysis of soil extracts in the small potted plant and actual water samples in the environment. It is expected that the microfluidic chip with the LC-ECD-SERS synchronous detection system has significant potential in various environmental, food safety, drug, and biomedical analyses.