High Catalytic Activity of Fluorophore-Labeled Y-Shaped DNAzyme/3D MOF-MoS 2 NBs as a Versatile Biosensing Platform for the Simultaneous Detection of Hg 2+ , Ni 2+ , and Ag + Ions

作者：Rajaji Pavadai, Arunjegan Amalraj, S. Sivanesan, Panneerselvam Perumal · 发表于：ACS Applied Materials & Interfaces · 年份：2021 · DOI：10.1021/acsami.1c07086 · 被引用次数：78 · 研究领域：Advanced biosensing and bioanalysis techniques、Advanced Nanomaterials in Catalysis、MXene and MAX Phase Materials

In this study, we have designed a three-fluorophore-labeled Y-shaped DNAzyme with a high catalytic cleavage activity and a three-dimensional (3D) MOF-MoS 2 NB (metal–organic framework fused with molybdenum disulfide nanobox), which was synthesized as an efficient quencher of the fluorescent biosensor. The synthesized porous 3D MOF-MoS 2 NBs and Y-shaped DNAzyme exhibited a good analytical response toward the simultaneous multiple detections of Hg 2+, Ni 2+, and Ag + ions over the other coexisting metal ions. More specifically, the three kinds of enzyme aptamer and substrate aptamer (SA) were hybridized and annealed to form the Y-shaped DNAzyme structure and labeled with three different fluorophores such as FAM, TAMRA, and ROX over the 3′-end of SA. When the targets were induced, the DNAzyme was triggered to cleave the fluorophore-labeled SAs. Then, the cleaved SAs (FAM-SA, TAMRA-SA, and ROX-SA) were adsorbed on the 3D MOF-MoS 2 NB surface to quench the fluorescence signal due to a noncovalent interaction (van der Waals and π–π stacking interaction), which transmuted the fluorescence on-state to off-state. As a result, the fluorescence assay confiscated the high selectivity and sensitivity for the target analytes of Hg 2+, Ni 2+, and Ag + ions achieved for the detection limits of 0.11 nM, 7.8 μM, and 0.25 nM, respectively. Accordingly, the sensitivity of the developed sensor was explored with a better lower detection limit than the previously reported biosensors. The utility o...