A multifunctional hemin@metal–organic framework and its application to construct an electrochemical aptasensor for thrombin detection

Abstract

A new type of multifunctional metal-organic framework (MOF) has been synthesized by encapsulating hemin into the nano-sized Fe-MIL-88 MOFs (hemin@MOFs) and first applied in an electrochemical aptasensor to detect thrombin (TB) with the aid of an enzyme for signal amplification. The gold nanoparticle functionalized hemin@MOFs (Au/hemin@MOFs) have not only simultaneously served as redox mediators and solid electrocatalysts, but have also been utilized as an ideal loading platform to immobilize a large number of biomolecules. In this aptasensor, Au/hemin@MOFs conjugated with glucose oxidase (GOD) and thrombin binding aptamer (TBA II) were used as the secondary aptamer bioconjugates (Au/hemin@MOF-TBA II-GOD bioconjugates), and TB was sandwiched between Au/hemin@MOF-TBA II-GOD bioconjugates and the amino-terminated TBA I which was self-assembled on the gold nanoparticle (AuNP) modified electrode. The GOD could oxidize glucose into gluconic acid accompanied by the generation of H2O2. The generated H2O2 on the electrode surface was further electrocatalyzed by hemin@MOFs to amplify the electrochemical signal of hemin contained in hemin@MOFs. Therefore, the synthesized hemin@MOFs represented a new paradigm for multifunctional materials since it combined three different functions including serving as catalysts, redox mediators and loading platforms within a single material. With such an ingenious design, a wide linear range of 0.0001 nM to 30 nM was acquired with a relatively low detection limit of 0.068 pM for TB detection.

Templated Synthesis of Nickel−Iron Layered Double Hydroxide for Enhanced Electrocatalytic Water Oxidation: Towards the Development of Non‐Precious‐Metal Catalysts

“…The XRD patterns of Fe‐MIL‐88 and Ni−Fe LDH are shown in Figure S3. The XRD pattern of Fe‐MIL‐88 show peaks at 8.9, 16.2 and 17.3° which may be corroborated to (002), (103) and (200) plane of Fe‐MIL‐88 (Figure S3a) . After the formation of LDH some new peaks are observed.…”

“…These properties of MOFs have been potentially applied in gas storage and separation, sensors, catalysis, and energy storage . Recently the use of MOFs as template to synthesize LDH nanocages is burgeoning ,. In this respect, various types of LDHs such as Mg−Co LDH, Ni−Co LDH, Co LDH and ZnAl‐CO 3 LDH have been synthesized successfully and used as electrode modifiers ,.…”

Glassy carbon electrode modified with hemin and new melamine compounds for H2O2 amperometric detection

“…That is, the proton interchange was, by far, significant in Hm-Den mixture with respect to that revealed by Hm-Dim one. The major structural differences between melamines Dim and Den consisted mainly on their size (Scheme 2) and global shape, planar against vaulted, respectively; at this stage of our knowledge, we hypothesized a partial encapsulation of planar Hm (an already published [31][32][33][34] aptitude of this metaloporphyrine) by a multi-branched structure [31] such as Den, creating a new potential metal-organic framework (MOF) [32][33][34].…”

G-quadruplex-based aptamers against protein targets in therapy and diagnostics

“…In a similar system, the same authors used another enzyme, glucose oxidase (GOx), to construct a sensitive electrochemical aptasensor for thrombin, exploiting the enzyme-assisted signal amplification strategy. They employed the synergistic effect of hemin as a peroxidase mimic, of the enzymatic activity of GOx, and of the sandwich-type recognition of thrombin by the two TBAs (TBA 15 and TBA 29 ) [193]. The system has been obtained combining two components: 1) a multifunctional bionanocomposite in solution composed of nano-sized Fe-MIL-88 MOFs encapsulating hemin and functionalized with gold nanoparticles, glucose oxidase and TBA 29 (Fig.…”