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Preparation of Multifunctional Silk-Based Microcapsules Loaded with DNA Plasmids Encoding RNA Aptamers and Riboswitches
Published on: October 8, 2021
Cu/Au/Pt trimetallic nanoparticles coated with DNA hydrogel as target-responsive and signal-amplification material
Pian Wu1, Shuang Li2, Xiaosheng Ye3
1Xiang Ya School of Public Health, Central South University, Changsha, Hunan, 410078, PR China; Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Tianjin Institute of Environment and Operational Medicine, Tianjin, 300050, PR China; Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan, 410078, PR China.
Abstract:
Sensitive and reliable analytical methods for monitoring of microcystin-LR (MC-LR) are urgently necessary due to its great harm to human health and aquatic organisms. In this work, a novel Cu/Au/Pt trimetallic nanoparticles (Cu/Au/Pt TNs)-encapsulated DNA hydrogel was prepared for colorimetric detection of MC-LR. The Cu/Au/Pt TNs were captured and released with precise control by the target-responsive 3D DNA hydrogels, which combined dual advantages of the target responsive DNA hydrogel and Cu/Au/Pt TNs of enhanced peroxidase-like activity. The DNA hydrogel network was constructed by hybridizing MC-LR aptamer with two complementary DNA strands on linear polyacrylamide chains. As long as MC-LR presented, the aptamer competitively binds with the MC-LR, causing the hydrogel to dissolve and release the preloaded Cu/Au/Pt TNs which could catalyze the reaction between H2O2 and TMB to produce color changes. In view of this sensitive strategy, this Cu/Au/Pt TNs-encapsulated DNA hydrogel-based colorimetric biosensor can achieve quantitative determination of MC-LR. The results showed that as-proposed colorimetric biosensor could sensitively detect MC-LR with a linear range of 4.0-10000 ng L-1 and a detection limit of 3.0 ng L-1. This work proved that the sensor had great potential to be applied in MC-LR detection and also provided the opportunity to develop colorimetric biosensor for other targets using this target-responsive and signal-amplification strategy.

