Abstract
Extensive consumption of cobalt in the chemical field such as for battery materials, alloy, pigments, and dyes has aggravated the pollution of cobalt both in food and the environment, and assays for its on-site monitoring are urgently demanded. Herein, we utilized enzyme dependence on metal cofactors to develop terminal transferase (TdT) as a recognition element, achieving a one-pot sensitive and specific assay for detecting cobalt pollution. We engineered a 3′-OH terminus primer to improve the discrimination capacity of TdT for Co2+ from other bivalent cations. The TdT extension reaction amplified the recognition of Co2+ and yielded a limit of detection of 0.99 μM for Co2+ detection. Then, the TdT-based assay was designed to precisely detect cobalt in food and agricultural soil samples. By end-measurement of fluorescence using a microplate reader, the multiplexing assay enabled the rapid screening of the peptide remover for cobalt pollution. The TdT-based assay can be a promising tool for cobalt pollution monitoring and control.