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论文类型：期刊论文

发表时间：2020-01-15

发表刊物：SENSORS AND ACTUATORS B-CHEMICAL

收录刊物：EI、SCIE

卷号：303

关键字：OTC detection; Surface passivation; Covalent linkage; MOF nanosheets; Physisorption strategy; Fluorescent aptasensor

摘要：The physisorption strategy is an universal sensing principle in fluorescent platform design, which have realized the successful detection for various targets based on nanomaterial-enabled sensors. However, this type of "turn-on" biosensor is still faced with the dilemma of low detection sensitivity, which was mostly caused by nonspecific probe displacement and relative low desorption efficiency. As a result, the extensive suitability of physisorption strategy in "turn-on" fluorescent platform has been restricted. In this work, we have established covalent-linked 2D MOF-DNA nanosystem and employed FAM-labelled short-chain as signal reporter. To further improve the detection performance for oxytetracycline (OTC), we also screened a series of blocking agents to passivate the surface of MOF nanosheets and avoid the adsorption of DNA reporter. Compared with directly covalent-linked nanosensor, the nanosensor treated with short-chain DNA reporter and surface passivation has not only possessed intrinsic specificity as apasensor but also exhibited enhanced detection performance for OTC with a linear range of 0.50-5.00 mu g/L and a LOD of 0.40 mu/L (3 delta/s). The as-developed strategy has shown its great potentials in a variety of nanosheets-DNA sensing systems, especially favorable for those nanomaterials with poor affinity towards DNA.