A centrifugal microfluidic system for automated detection of multiple heavy metal ions by aptamer-based colorimetric assay

The contamination of aquatic environments with heavy metal ions is characterized by their resistance to natural degradation, leading to their bioaccumulation in plants and animals, consequently posing a significant threat to human health. The detection of toxic metal ions is of great significance in environmental protection and disease prevention. In this work, a rapid and automated method for the simultaneous detection of Pb 2+ , Hg 2+ and As 3+ in water was proposed. An aptamer-based colorimetric assay and a centrifugal microfluidic chip to realize the function of sampling, mixing, reaction etc. The microfluidic chip and centrifugal device were properly designed and developed. Besides, the detection parameters were optimized by analyzing the sensitivity and selectivity. Results showed that the detection system was able to realize the automatic detection of the multiple heavy metal ions within 30 min, and the limits of detection for Pb 2+ , Hg 2+ and As 3+ were 6.16 ppb, 4.97 ppb and 5.24 ppb. The self-developed system can be utilized as a promising platform for the rapid detection of multiple heavy metal ions in practical applications.