Dual-mode sensing platform for detection of multiple metal ions based on amine-functionalized MIL-101 (Fe) cascade Y-Shaped DNAzyme-assisted fluorescence and colorimetric analysis

Abstract

Our environment is being polluted by numerous sources of heavy metals by various industries and monitoring the heavy metals is very essential in environment and other field. Herein, amine-functionalized metal organic framework (NH2-MIL-101(Fe)) were prepared by hydrothermal method. The DNA sequences with enzyme and substrate strand were annealed to form Y-Shaped DNAzyme and used for recognition element. We developed a fluorescence/colorimetric dual channel for sensitive detection of Pb2+, Hg2+ and Cu2+ using NH2-MIL-101(Fe) and Y-Shaped DNAzyme with magnetic separation. A good linear correlation and detection limit were observed by fluorescence method like 0.21 nM for Pb2+, 0.23 nM for Hg2+ and 0.37 nM for Cu2+ and by colorimetric method such as 0.43nM for Pb2+, 0.57 nM for Hg2+ and 0.99 nM for Cu2+.Therefore, we have conventional method for dual-mode detection of Pb2+, Hg2+ and Cu2+ ions with high specificity, accuracy and satisfactory results are obtained in the real sample analysis.