Emerging as a new member of the 2D family, two-dimensional (2D) metal-organic framework (MOF) nanosheets have received increasing attention in recent years and been explored their application in catalysis, separation and sensing. To improve the practicability of 2D MOF nanosheets as universal fluorescent platforms, we have employed partially hybridized DNA as probe as well as surface passivation technique to optimize the detection performance for oxytetracycline. The DNA probe was covalently linked to 2D MOF nanosheets (Cu(HBTC)-1) in order to avoid nonspecific displacement, thus eliminating possible false positive signals and improving the specificity of as-proposed sensor. We also found that polystyrenesulfonate (PSS) and poly-C DNA were efficient blocking agents, which would increase the target-induced DNA reporter desorption. Furthermore, the surface passivation also facilitated the desorption of partially hybridized short-chain ssDNA reporter (FAM-labelled), which could prominently enhance the target-induced signal responses. By taking advantage of passivation using PSS and short-chain DNA reporter, the capability of 2D MOF nanosheets to detect oxytetracycline (OTC) was successfully extended to nanogram per liter, superior to conventional fluorescent analytical methods. We further explored their potential application as colorimetric sensing platforms. By preparing bimetallic nanoparticles anchored Cu(HBTC)-1/Fe3O4-AuNPs nanosheets with high-efficient peroxidase-like catalytic activity, the 2D MOF nanosheets could be promising nanomaterials for colorimetric sensors. Particularly, its intrinsic peroxidase-like catalytic activity could be flexibly regulated by DNA, exhibiting the enhancement of 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation or inhibition of 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) oxidation due to the adsorption of ssDNA via π-π stacking. Therefore, by virtue of its enhanced and controllable peroxidase-like catalytic activity, the 2D MOF nanosheets have achieved ultra-sensitive detection for H2O2 reaching up to nanomolar concentration, comparable detection performance for glucose, as well as sensitive detection for sulfadimethoxine (SDM). With the multiplexed performance for detecting various targets as optical sensing platforms, our as-synthesized 2D MOF nanosheets hold great promise for the applications in environmental monitoring, as well as bioassay by virtue of its well biocompatibility.

Establishing optical sensing platforms using 2D metal-organic framework nanosheets for antibiotics detection

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.