Double Molecular Recognition Research Articles

Double molecular recognition ligands modified CPDS/CMCS/Fe3O4-rGO hybrid with enhanced enrichment capacity for glycoproteins at neutral environment

Abstract In order to achieve specific enrichment of target glycoproteins, double molecular recognition ligands functionalized surface solid-phase adsorption materials that can play a role under physiological pH conditions, have obvious advantages. In this work, a novel strategy was proposed for the synthesis of double molecular recognition functionalized magnetic graphene nanocomposites. Horseradish peroxidase was selected as the template proteins for evaluating the selectivity and binding capacity of the adsorption material. The bimolecular recognition was realized by introducing 4-carboxyphenylboronic acid (CPBA) and Suberic acid bis(3-sulfo-N-hydroxysuccinimide ester) sodium salt (Sulfo-DSS) as functional ligands. The abundant oxygen-containing groups in the complex (abbreviated as CPDS/CMCS/Fe3O4-rGO) were beneficial to reduce the pKa value of CPBA. Finally, CPDS/CMCS/Fe3O4-rGO realized the selective adsorption of glycoproteins in the neutral environment (pH 7.0). The resultant CPDS/CMCS/Fe3O4-rGO exhibited a high adsorption capacity of 1280.6 mg g−1 and excellent specificity toward glycoproteins compared to nonglycoproteins. Moreover, CPDS/CMCS/Fe3O4-rGO with strong magnetic responses (59.29 emu·g−1), could achieve rapid aggregation and separation under the external magnetic field. The results demonstrated the great potential of CPDS/CMCS/Fe3O4-rGO composites to separate and enrich glycoproteins from the complex biological sample for the glycoproteins analysis.

Ultrasensitive sandwich-like electrochemical biosensor based on core-shell Pt@CeO2 as signal tags and double molecular recognition for cerebral dopamine detection

In this report, 4-mercaptophenylboronic acid (MBA) and dithiobis (succinimidyl propionate) (DSP) were used as DA molecular recognizer, which bounded onto the prepared Pt@CeO2 nanomaterial and the electrode surface. A sandwich-like electrochemical biosensor was constructed for sensitive detection of dopamine (DA) based on double molecular recognition and Pt@CeO2 (MBA-DSP- Pt@CeO2) as an electrochemical probe for signal amplification. It is worth noting that the diol and amine groups of DA were reacted by the boronic acid of MBA and the succinimide residue of DSP, respectively. This sandwich-like double molecular interaction can efficiently and accurately identify DA. The uniform Pt@CeO2 multicore@shell nanospheres as signal tags and signal amplifiers in electrochemical biosensor were synthesized by hydrothermal, which has excellent catalytic activity for H2O2. Interestingly, more oxygen vacancies were produced in the lattice structure of CeO2 doped with Pt, so that the catalytic and redox performance of the obtained Pt@CeO2 was much better than that of pure CeO2, thus greatly improving the performance of the proposed sensor. The proposed electrochemical biosensor provided a wide detection range of 2–180 nM and a low detection limit (0.71 nM) by the electrochemical measurement. And it also showed ultra-high sensitivity, accuracy and broad application prospect, which developed a new research method for early clinical diagnosis.

Double molecular recognition strategy based on boronic acid-diol and NHS ester-amine for selective electrochemical detection of cerebral dopamine.

Electrochemical detection of dopamine (DA) usually depends on electrochemical oxidation of DA. This conventional method can hardly provide sufficient sensitivity and selectivity in the determination of the cerebral DA down to nanomolar level, because the ability of DA to be electrochemically oxidized is limited and many electroactive interferents are also oxidized at a similar potential with DA. Here, an electrochemical assay based on a double molecular recognition strategy has been proposed and proved to be of high sensitivity and selectivity for DA measurement in the cerebral system. 3,3'-Dithiodipropionic acid di(N-hydroxysuccinimide ester) (DSP) was anchored on the electrode surface to capture DA target through the specific reaction between N-hydroxysuccinimide (NHS) ester and amine. The captured DA endowed the electrode with a layer of diol groups, which further reacted with the boronic acid to trap of 4-mercaptophenylboronic acid (MBA) molecules, thus leading to the conjunction of electroactive thionine (Th) molecules on the electrode for signal readout. In addition, an Au nanostructure was employed to enhance signal amplification and facilitate the double molecular recognition process. As a consequence, this method was able to quantify DA from 1 to 300nM with a detection limit of 0.74nM, which exhibited a high specificity against cerebral interferents. Furthermore, the practicability of this platform was successfully demonstrated through determination of the dynamics of cerebral DA in the events of high K+ and nomifensine retromicrodialysis. Graphical abstract.

A Colorimetric Probe for the Selective Detection of Norepinephrine Based on a Double Molecular Recognition with Functionalized Gold Nanoparticles

A simple colorimetric probe for the selective and sensitive detection of neurotransmitter norepinephrine (NE), an important biomarker in the detection of tumors such as pheochromocytoma and paraganglioma, is described. The sensing strategy is based on the use of spherical gold nanoparticles functionalized with benzaldehyde and boronic acid-terminated moieties. A double molecular recognition involving on one hand the aromatic aldehyde and the aminoalcohol group of NE, and on the other hand the boronic acid and the catechol moiety of the neurotransmitter, results in analyte triggered aggregation of the gold nanoparticles, leading to a bathochromic shift of the SPR band in the UV–vis spectrum of the probe and a clear change in the color of the solution from red to blue. Probe P1 shows a remarkable selectivity toward NE versus other catecholamine neurotransmitters (dopamine and epinephrine) and selected biomolecules (5-HIAA, l-Tyr, glucose, uric acid, Lys and glutamic acid). Moreover, a linear response to NE ...

An electrochemical biosensor based on double molecular recognition for selective monitoring of cerebral dopamine dynamics at 4 min interval

Dopamine (DA) monitoring with high selectivity and sensitivity in the cerebrally extracellular fluid is of high value for evaluating the role of DA in the physiological and pathological processes. Especially because neurotransmission involved in rapid events, lowering the detection interval in order to gain more insight into DA dynamics inserts great challenge into the DA analytical method. In this work, a facile electrochemical biosensor for sensing DA with high sensitivity was developed here. Double molecular recognition based on boronic acid-diol and N-hydroxysuccinimide ester-amine endows the new biosensor favourable selectivity for cerebral DA detection. More importantly, microdialysate volume as low as 7 μL was requisite for the DA analysis without suffering from a sensitivity loss, thus monitoring DA concentration in brain microdialysate at 4 min interval was successfully achieved. Subsequently, the present biosensor was successfully employed for monitoring of cerebral DA transients evoked by high K+ and nomifensine.

Colorimetric detection of normetanephrine, a pheochromocytoma biomarker, using bifunctionalised gold nanoparticles

A simple and effective colorimetric method for the detection of normetanephrine (NMN), an O-methylated metabolite of norepinephrine, using functionalised gold nanoparticles is described. This metabolite is an important biomarker in the diagnosis of adrenal tumours such as pheocromocytoma or paraganglioma. The colorimetric probe consists of spherical gold nanoparticles (AuNPs) functionalised with two different ligands, which specifically recognize different functional groups in normetanephrine. Thus, a benzaldehyde-terminated ligand was used for the recognition of the amino alcohol moiety in NMN, by forming the corresponding oxazolidine. On the other hand, N-acetyl-cysteine was chosen for the recognition of the phenolic hydroxyl group through the formation of hydrogen bonds. The selective double molecular recognition between the probe and the hydroxyl and the amino-alcohol moieties of normetanephrine led to interparticle-crosslinking aggregation resulting in a change in the color of the solution, from red to blue, which could be observed by naked eye. The probe was highly selective towards normetanephrine and no color changes were observed in the presence of other neurotransmitter metabolites such as homovanillic acid (HVA) (dopamine metabolite), 5-hydroxyindoleacetic acid (5-HIAA) (serotonin metabolite), or other biomolecules present in urine such as glucose (Glc), uric acid (U.A), and urea. Finally, the probe was evaluated in synthetic urine with constituents that mimic human urine, where a limit of detection of 0.5 μM was achieved.

New detection method for nucleoside triphosphates based on carbon dots: The distance-dependent singlet oxygen trapping

The distance-dependent based sensing mechanism, such as fluorescence resonance energy transfer (FRET) and surface plasmon resonance (SPR) absorption of gold nanoparticles, has been used widely in visual detection. In this work, we report another distance-dependent detection method for nucleoside triphosphates (NTPs) based on carbon dots (CDs) (1O2 donor) and 9, 10-diphenylanthracene-2-boronic acid (DABA, 1O2 acceptor). The CDs can generate singlet oxygen (1O2) which allows diffusion within 200 nm. Thus, the distance between CDs and DABA decreased through binding of NTPs (<200 nm), leading to absorption changes of DABA under light irradiation due to 1O2 trapping. This sensing system (CDs@DABA) has high selectivity for the detection of NTPs due to the double molecular recognition and a linear response in the 0–80 μM concentration range was accomplished with the detection limit as low as 4.35 μM.

Supramolecular Alternating Polymer from Crown Ether and Pillar[5]arene-Based Double Molecular Recognition for Preparation of Hierarchical Materials.

A novel supramolecular alternating polymer is constructed based on double molecular recognition events of benzo-21-crown-7 with a secondary ammonium salt and of pillar[5]arene with a neutral guest. The resulting polymer is utilized to prepare hierarchical materials with different dimensionalities for the first time. These materials included zero-dimensional spherical aggregates, one-dimensional nanofibers, two-dimensional microstructured films, and three-dimensional ordered glue. This development will be helpful for designing and preparing supramolecular hierarchical materials with different dimensionalities.

Fast, sensitive and selective colorimetric gold bioassay for dopamine detection.

Colorimetric detection of dopamine has the advantage of simplicity in operation and instrumentation. Herein, a highly sensitive and selective colorimetric biosensor with fast response has been developed by using 4'-aminobenzo-18-crown-6 (ABCE) and 4-mercaptophenyl boronic acid (MPBA) modified Au nanoparticles. The modified probe shows an excellent detection limit of 6.0 nM of dopamine at a S/N of 2.01 and about 46 nM at a S/N of 3 within microseconds response. It exhibits excellent detection selectivity even in 1000-fold excess of many different interferents like metal ions, uric acid and ascorbic acid. All these may make it fulfill the requirements for in vivo analysis.

A Chloroacetate‐Caged Fluorescein Chemodosimeter for Imaging Cysteine/Homocysteine in Living Cells

AbstractA chloroacetate‐caged fluorescein chemodosimeter (CACFC) employing a double molecular recognition mechanism was designed and synthesized to selectively detect cysteine (Cys) and homocysteine (Hcy) over glutathione (GSH) and other amino acids. The results showed that CACFC could serve as a “naked‐eye” indicator, and quantitatively detect Cys and Hcy with a detection limit of 4 μM (Cys) and 7 μM (Hcy). Additionally, CACFC was successfully applied to the fluorescence imaging of Cys and Hcy in living cells. The mechanism of the reaction between CACFC and Cys/Hcy was confirmed by ESI‐MS and fluorescence spectroscopic analysis to involve a conjugate substitution/cyclization sequence. We highlight the simplicity of the design and synthesis and show that its combined properties, such as high specificity, high sensitivity, fast response, quantitative detection and real time Cys and Hcy imaging in living cells should find applications in imaging and biomedical fields.

Double Molecular Recognition with Aminoorganoboron Complexes: Selective Alcoholysis of β‐Dicarbonyl Derivatives

Aminoorganoboron complexes such as AOB recognize alcohol and β-dicarbonyl units, and then facilitate chemo- and site-selective alcoholysis of the β-dicarbonyl unit.

Double Molecular Recognition with Aminoorganoboron Complexes: Selective Alcoholysis of β‐Dicarbonyl Derivatives

Double Molecular Recognition with Aminoorganoboron Complexes: Selective Alcoholysis of β‐Dicarbonyl Derivatives

Sensitive and Selective Colorimetric Visualization of Cerebral Dopamine Based on Double Molecular Recognition

Seeing is believing: A direct, selective, and sensitive strategy for colorimetric visualization of cerebral dopamine has been developed for the first time using gold nanoparticles through the design of double molecular recognition (see picture). The simplicity of this method establishes a facile and reliable approach for monitoring cerebral species in brain chemistry, which may be related to physiological and pathological events.

Sensitive and Selective Colorimetric Visualization of Cerebral Dopamine Based on Double Molecular Recognition

Was geht in deinem Kopf vor? Eine direkte, selektive und empfindliche Strategie zur kolorimetrischen Visualisierung von zerebralem Dopamin beruht auf der Verwendung von Goldnanopartikeln und doppelter molekularer Erkennung (siehe Bild). Diese Strategie bietet einen einfachen und zuverlässigen Ansatz zur Verfolgung molekularer Spezies im Gehirn, die mit physiologischen und pathologischen Vorgängen zusammenhängen könnten.

Novel supramolecular system of amphiphilic hyperbranched polymer with β-cyclodextrin and hyperbranched topography cavities: Synthesis and selective encapsulation

Novel supramolecular system of amphiphilic hyperbranched polymer with hyperbranched poly(β-cyclodextrin) core was designed and synthesized to accomplish a so-called selective encapsulation, where two types of guest molecules can be encapsulated into two types of molecular cavities from β-cyclodextrin (β-CD) and topography structure of hyperbranched polymer, respectively. The double molecular recognition behaviors from β-CD and hyperbranched cavities drive one guest to go into the former, the other guest to the latter. This selective encapsulation was further confirmed via the release profiles and sequences of Levofloxacin lactate (LL) and Phenolphthalein (PP). LL presents a sustained release period followed by an almost non-release stage, while PP releases on a quite slow rate at first, subsequently on the linearly increasing rate. At the early stage, the release of LL dominates in comparison with PP, and then the release rate of PP increases to play a determinate role in the release system. It can be attributed to the existence of two guests in the different molecular cavities with the different microenvironments. The observed selective encapsulation of supramolecular system is a new phenomenon, which is helpful to extend the application of CD-based hyperbranched polymers in supramolecular science and complex drug delivery system.