Archives

  • 2018-07
  • 2018-10
  • 2018-11
  • 2019-04
  • 2019-05
  • 2019-06
  • 2019-07
  • 2019-08
  • 2019-09
  • 2019-10
  • 2019-11
  • 2019-12
  • 2020-01
  • 2020-02
  • 2020-03
  • 2020-04
  • 2020-05
  • 2020-06
  • 2020-07
  • 2020-08
  • 2020-09
  • 2020-10
  • 2020-11
  • 2020-12
  • 2021-01
  • 2021-02
  • 2021-03
  • 2021-04
  • 2021-05
  • 2021-06
  • 2021-07
  • 2021-08
  • 2021-09
  • 2021-10
  • 2021-11
  • 2021-12
  • 2022-01
  • 2022-02
  • 2022-03
  • 2022-04
  • 2022-05
  • 2022-06
  • 2022-07
  • 2022-08
  • 2022-09
  • 2022-10
  • 2022-11
  • 2022-12
  • 2023-01
  • 2023-02
  • 2023-03
  • 2023-04
  • 2023-05
  • 2023-06
  • 2023-07
  • 2023-08
  • 2023-09
  • 2023-10
  • 2023-11
  • 2023-12
  • 2024-01
  • 2024-02
  • 2024-03
  • 2024-04
  • rociletinib Recently biosensors based on enzyme

    2024-02-23

    Recently, biosensors based on enzyme-mimicking organic-inorganic hybrid nanomaterials such as protein or DNA-Cu nanoflowers (Batule et al., 2015, Park et al., 2017), Fe-aminoclay (Lee et al., 2013), and MOFs (Ai et al., 2013, Dong et al., 2015, Feng et al., 2012, Liu et al., 2013, Qin et al., 2013, Zhang et al., 2014) have been successfully exploited. Among these, MOFs have emerged as a new class of crystalline hybrid porous materials by taking advantages of their intriguing structural properties such as high specific surface area, tunable pore size distribution, coordinatively unsaturated metal sites (CUS) in the skeleton, and practically limitless choice of metals and organic ligands affording an essentially infinite number of possible combinations. These fascinating features led them to be widely used in many fields, such as gas storage (Llewellyn et al., 2008, Murray et al., 2009), gas rociletinib (Li et al., 2012, Wuttke et al., 2012), catalysis (Horcajada et al., 2007, Lee et al., 2009, Valekar et al., 2016), and sensing (Desai et al., 2015, Kumar et al., 2015, Meilikhov et al., 2013, Nagarkar et al., 2013). Besides their aforementioned unique properties, MOFs provide great potential for the further functionalization of their structures. According to the literature, post synthetic modification (PSM, where one can do the modification in original MOF structure after its synthesis) is considered as the most common method to achieve the desired functionality in MOFs, subsequently, anticipated chemical and physical property can be imparted (Tanabe and Cohen, 2011). Therefore, a large number of functional MOFs have been prepared using the PSM and successfully utilized to improve their performance in catalysis (Banerjee et al., 2009, Hwang et al., 2008, Kasinathan et al., 2011) and gas storage (Dinca et al., 2007, Wang and Cohen, 2009). However, functionalized MOFs containing redox-active metal centers have rarely been used as peroxidase mimics mainly due to their hydrothermal and chemical instability (Larsen et al., 2011, Qin et al., 2013). The previous reported MOF biosensors are simply used either as synthesized Fe based MOFs such as MIL-53, MIL-68, MIL-88-NH2, MIL-100, and MIL-101, or Hemin@MIL-101(Al)-NH2 composite for peroxidase mimics (Ai et al., 2013, Dong et al., 2015, Feng et al., 2012, Liu et al., 2013, Qin et al., 2013, Zhang et al., 2014). However, these studies did not utilize one of the most promising approaches of functionalizing MOF on CUS with desired functionality. In this work, we took this opportunity for the first time and functionalized MIL-100(Fe) by grafting various aliphatic diamines on its CUS. The performance of functionalized MIL-100(Fe) for peroxidase mimic activity enhanced significantly compared to its pristine form presumably due to the synergetic effect of the enhanced negative potential and precisely controlled molecular size of the grafted diamines. Based on this enhanced peroxidase-like activity, we developed a simple and effective fluorescent method for the quantitative determination of choline and acetylcholine. These two biomolecules serve as important regulators in many biological processes including nutrition and neurotransmission, however until now, their detection methods have been suffered from many limitations such as low sensitivity, unstable signal, and complex experimental steps (Chen et al., 2011). Thus, there is a significant incentive to develop sensitive, reliable, and convenient assay of choline and acetylcholine. Herein, we used amine-functionalized MOFs coupled with enzymes specific for choline and acetylcholine for the successful detection of choline and acetylcholine even present in spiked samples of milk and serum, respectively.
    Experimental section
    Results and discussion
    Conclusions In this study, we successfully synthesized various diamine-grafted MIL-100(Fe) and for the first time systematically investigated their peroxidase-like activity. The characterization data of the amine-grafted MIL-100(Fe) were well correlated with their peroxidase-mimicking activity and it was suggested that the improved catalytic activity was due to the enhanced negative potential of the amine-grafted MIL-100(Fe) and controlled size of the grafted diamine, which helped to bring the substrate in close proximity with the active Fe(III) centers present on the MOF surface. However, the detection mechanism underlying these effects remains to be determined. We further utilized the highly enhanced peroxidase activity of the amine-grafted MIL-100(Fe) to develop a simple fluorescent assay to detect choline and acetylcholine with significantly low detection limits (0.027 and 0.036┬ÁM respectively). The present work encouraging the further investigations in post-synthetic functionalization of MOFs to design new functional nanomaterials as enzymatic mimetics capable of detecting biomolecules.