Porphyrin-Encapsulated Metal–Organic Frameworks as Mimetic Catalysts for Electrochemical DNA Sensing via Allosteric Switch of Hairpin DNA

Abstract

A sensitive electrochemical sensor is designed for DNA detection based on mimetic catalysis of metal-organic framework (MOF) and allosteric switch of hairpin DNA. The functional MOFs are synthesized as signal probes by a one-pot encapsulation of iron(III) meso-5,10,15,20-tetrakis(4-carboxyphenyl) porphyrin chloride (FeTCPP) into a prototypal MOF, HKUST-1(Cu), and sequentially conjugated with streptavidin (SA) as a recognition element. The resulting FeTCPP@MOF composites can mimetically catalyze the oxidation of o-phenylenediamine (o-PD) to 2,2'-diaminoazobenzene, which is a good electrochemical indicator for signal readout. The presence of target DNA introduces the allosteric switch of hairpin DNA to form SA aptamer, and thus, FeTCPP@MOF-SA probe is brought on the electrode surface via the specific recognition between SA and the corresponding aptamer, resulting in the enhancement of electrochemical signal. The "signal-on" electrochemical sensor can detect target DNA down to 0.48 fM with the linear range of 10 fM to 10 nM. Moreover, the MOF-based electrochemical sensor exhibits acceptable selectivity against even a single mismatched DNA and good feasibility in complex serum matrixes. This strategy opens up a new direction of porphyrin-functionalized MOF for signal transduction in electrochemical biosensing.

Magnetic Zirconium Hexacyanoferrate(II) Nanoparticle as Tracing Tag for Electrochemical DNA Assay

“…The MBs are nearspherical with a relatively smooth surface ( Figure 1A), and the particle size is about 175 nm. In the process of the ZrHCF MNPs formation, first, the negatively charged ferricyanide ion (Fe(CN) 6 3− ) would be electrostatically adsorbed on their surface due to the protonation of amines on the surface of MBs. Second, dopamine can convert Fe(CN) 6 3− into its reduced form Fe(CN) 6 4− .…”

“…Chloroauricacid trihydrate ( H A u C l 4 · 3 H 2 O , C A S : 2 7 9 8 8 -7 7 -8 ) , p o t a s s i u m hexacyanoferrate(III) (K 3 Fe(CN) 6 , CAS: 13746-66-2), zirconyl chloride (ZrOCl 2 , CAS: 7699-43-6) solution (30% in hydrochloric acid (HCl)), dopamine hydrochloride (CAS: 62-31-7), and 6-mercapto-1-hexanol (MCH, 97%, CAS: 1633-78-9) were purchased from the local Sigma−Aldrich Chemical Co. (Shanghai, China). Iron oxide (Fe 3 O 4 ) superparamagnetic microbeads (MBs, 5 mg mL −1 , ∼100 nm in diameter) with amine (−NH 2 ) stabilizers in an aqueous suspension were obtained from Tianjin BaseLine Chromtech Research Centre (Tianjin, China).…”

“…ZrHCF naoparticles were prepared according to the reported method. 32 Briefly, K 3 Fe(CN) 6 , ZrOCl 2 , and dopamine were dissolved in 10 mM HCl aqueous solution, respectively. 1.0 mL of 10 mM K 3 Fe(CN) 6 , 1 mL of 10 mM ZrOCl 2 , and 1 mL of 1 mM dopamine were added in succession under vigorous stirring for 1 h. An ivory-white precipitate formed immediately.…”

β-Cyclodextrin as a Metal-anionic Porphyrin Complexation Accelerator in Aqueous Media

“…[1][2][3][4][5][6][7][8][9] In addition, metal-porphyrin complexes have various functions that are useful in analytical chemistry, and are also of interest to many other researchers, which has led to the use of metal-porphyrin complexes in applications such as optics, 10 chemical stacking, 11 catalysis, 12 electron transport, 13 oxidation-reduction reactions, 14 and biological mimicking substances. 15,16 Thus, numerous reports regarding the chemical function and applications of porphyrin derivatives have been published.…”

Electrochemical, spectroscopic, and theoretical studies on the interaction between azathioprine and DNA

“…Different techniques have been employed to study the interaction of small molecules with DNA, including fluorescence spectroscopy [5], UV-Visible spectrophotometry [6][7][8], circular dichroism [9], mass spectrometry [10], and electrochemical methods [11].…”