Metal-chelating Monomer Research Articles

Fabrication of Cholesterol‐Imprinted Microspheres‐Based Metal‐Chelating Monomer for Cholesterol Recognition from Serum

AbstractCholesterol is an essential lipid molecule associated with various physiological and pathological processes in the human body. Elevated cholesterol levels are correlated with several diseases, such as atherosclerosis, making cholesterol a critical biomarker for health monitoring. Molecular imprinting technology was selected to fabricate cholesterol imprinted microsphere (CHOL‐IP). This approach creates tailor‐made binding sites within polymer matrices for capturing cholesterol. However, the limited functional group in steroid derivative pose a challenge for the imprinting strategy. In this study, we successfully synthesized CHOL‐IP using a metal chelating monomer, N,N′‐vinylbenzyl iminodiacetic acid (VBIDA), in conjunction with copper (II) ions. The metal coordination approach facilitated strong binding forces, resulting in improved stability and specificity of the molecularly imprinted polymer (MIP). The synthesized CHOL‐IP was tested with pooled human serum samples containing cholesterol, HDL, and LDL. The CHOL‐IP exhibited significantly higher binding efficiency towards these compounds compared to the control polymer (CP). The application of a metal‐chelating functional monomer in the synthesized CHOL‐IP revealed the potential for enhancing its strong binding property toward cholesterol. This suggests that CHOL‐IP could be employed in the development of a cholesterol‐imprinted biosensor, providing an alternative tool for cholesterol analysis in medical detection applications.

A semi-covalent molecularly imprinted electrochemical sensor for rapid and selective detection of tiotropium bromide.

Tiotropium bromide (TIO) is a long-acting bronchodilator used in the treatment of chronic obstructive pulmonary disease (COPD) and asthma. Specifically, it is used to prevent patients from worsening breathing difficulties. In this study, a new TIO-imprinted electrochemical sensor was designed to detect TIO in serum and pharmaceutical samples. Methacryloyl-L-histidine-cobalt(II) [MAH-Co(II)] has been used as a metal-chelating monomer for synthesizing selective molecularly imprinted polymer (MIP). MIP film has been developed on glassy carbon electrodes using MAH-Co(II) as the functional monomer, 2-hydroxyethyl methacrylate (HEMA) as the basic monomer, and ethylene glycol dimethacrylate (EGDMA) as the cross-linker in the photopolymerization method. The surface characterization of the developed MAH-Co(II)@MIP/GCE electrochemical sensor was done using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Also, the electrochemical behavior of the sensor was provided by differential pulse voltammetry (DPV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. Under optimized experimental conditions, the linearity range was in the range of 10-100 fM, and the limit of detection (LOD) and limit of quantitation (LOQ) values were calculated as 2.73 fM and 9.75 fM, respectively. The MAH-Co(II)@MIP/GCE sensor was used to precisely determine TIO in capsule and commercial serum samples. The results demonstrated that the MIP could specifically recognize TIO compared to structurally related drugs and could be reliably applied to the direct determination of drugs from real samples.

Synthesis of a metal chelating monomer for radiation polymer dosimetry

To enhance the performance of polymeric dosimeters it is necessary to design novel formulations considering the mechanisms that register the absorbed dose (e.g. induced polymerization) and the readout method. The combination of the advantages of polymeric dosimetry, such as response stability and high sensitivity in a tissue-equivalent material, together with the high optical absorbance commonly found in colored metal-ligand complexes, represents a promissory strategy to achieve new dosimetry systems with enhanced optical properties. Addressing this scope, herein this study reports the synthesis of a vinylic monomer that was polymerized for the first time induced by X-Ray radiation, being also capable of forming highly colored complexes with metal ions. The chelating monomer was obtained from glycidyl methacrylate and iminodiacetic acid, purified and fully characterized. Then, the reactivity of a monomeric system containing the obtained monomer, N-isopropylacrylamide and N,N′-methylenebisacrylamide was evaluated. Two different initiation methods, namely chemically initiated polymerization and X-ray promoted polymerization were compared. Finally, the ability of the obtained polymers to chelate Cu2+ ions and the corresponding changes in their optical properties were studied.

Affinity binding of proteins to the modified bacterial cellulose nanofibers.

The potential of the modified bacterial cellulose (BC) nanofibers was determined bearing metal ion coordination interactions to enhance the protein adsorption and binding capacity. Thus, a household synthesized metal chelating monomer, namely N-methacryloyl-l-histidine methylester (MAH), and a commercial metal chelating monomer, namely 4-vinylimidazole (VIm), were used to complex with metal ions Cu(II) and Ni(II) respectively for the synthesis of the modified BC nanofibers. The modified nanofibers were characterized by FT-IR, SEM and EDX measurements. The protein adsorption tests were carried out using hemoglobin as a model protein and it was determined that the maximum adsorption capacity of hemoglobin onto the modified BC nanofibers was found as 47.40mg/g. The novel strategy for the preparation of metal chelated nanofibers was developed.

Phosphoserine imprinted nanosensor for detection of Cancer Antigen 125

Cancer antigen 125 (CA 125) is widely used as diagnostic biomarker for ovarian cancer. Change in the concentration level of CA 125 is associated with disease progression or regression. CA 125 posseses a phosphorylation site and protein backbone is phosphorylated on serine, before secretion. In this study, we have developed an imprinting method for CA 125 recognition and determination. In this method, methacryloyl antipyrine europium (III) [(MAAP)2-Eu(III)] and methacryloyl antipyrine terbium (III) [(MAAP)2-Tb(III)] have been used as new metal-chelating monomers via metal coordination–chelation interactions. Phosphoserine (PS) has been used as a template for the detection of CA 125. PS imprinted carbon nanotube (CNT) and Fe2O3 nanoparticle (SPN) have cavities that are selective for CA 125. The binding affinity of the PS imprinted CNT and SPN nanosensor has been investigated using Langmuir adsorption isotherms and affinity constants (Kaffinity) have found to be 1.85 105M−1 for PS and 13.5 10−3 mLU−1 and 7.73 10−3 mLU−1 for CA 125 (for CNT and SPN, respectively). Detection limit of PS imprinted CNT nanosensor for PS and CA 125 have been found to be 1.77 10−10M and 0.49 UmL−1, respectively. Human serum samples have been spiked with different concentrations of CA 125 (in pH 7.4 PBS) to investigate the feasibility of the nanosensors for clinical applications. Experimental results have been revealed that prepared nanosensors have been exhibited better sensivity, recovery and reproducibility.

Fabrication of Surface Protein-Imprinted Nanoparticles Using a Metal Chelating Monomer via Aqueous Precipitation Polymerization.

Molecular imprinting is a promising way for constructing artificial protein recognition materials, but it has been challenged by difficulties such as restricted biomacromolecule transfer in the cross-linked polymer networks, and reduced template-monomer interactions that are due to the required aqueous media. Herein, we propose a strategy for imprinting of histidine (His)-exposed proteins by combining previous approaches such as surface imprinting over nanostructures, utilization of metal coordination interactions, and adoption of aqueous precipitation polymerization capable of forming reversible physical crosslinks. With lysozyme as a model template bearing His residues, imprinted polymer nanoshells were grafted over vinyl-modified nanoparticles by aqueous precipitation copolymerization of a Cu(2+) chelating monomer with a temperature-responsive monomer carried out at 37 °C, above the volume phase-transition temperature (VPTT) of the final copolymer. The imprinted nanoshells showed significant temperature sensitivity and the template removal could be facilitated by swelling of the imprinted layers at 4 °C, below the VPTT. The resultant core-shell imprinted nanoparticles exhibited strikingly high rebinding selectivity against a variety of nontemplate proteins. An imprinting factor up to 22.7 was achieved, which is among the best values reported for protein imprinting, and a rather high specific binding capacity of 67.3 mg/g was obtained. Moreover, this approach was successfully extended to preliminary imprinting of hemoglobin, another protein with accessible His. Therefore, it may be a versatile method for fabrication of high-performance surface-imprinted nanoparticles toward His-exposed proteins.

Development of New Molecular Imprinted Solid Phase Extraction Material for Dimethoate

ABSTRACT In this study, we have proposed a novel organophosphate mimic surface molecular imprinted polymer for selective binding of the nerve agent by chitosan–Cd(II) as a new metal-chelating monomer via metal coordination–chelation interactions and dimethoate templates. We have improved a method for the selective binding behavior of dimethoate compounds on the surface of molecular imprinted polymer, which was prepared using ligand-exchange (chitosan–Cd(II)) monomers. The influence of ligand exchange imprinting on the creation of recognition sites toward dimethoate has determined application of adsorption isotherms. The effect of initial concentration of dimethoate, adsorption time, and imprinting efficiency on the adsorption selectivity for molecular imprinted polymer-ligand exchange has been investigated. The number of accessible sites (Qmax), relative selectivity coefficients (k′), and binding abilities have also been evaluated. Then, molecular imprinted polymer-ligand exchange was treated with formaldehyde to remove dimethoate templates.

Preparation of MIP-based QCM nanosensor for detection of caffeic acid

In the present work, a new caffeic acid imprinted quartz crystal microbalance (QCM) nanosensor has been designed for selective assignation of caffeic acid in plant materials. Methacrylamidoantipyrine-iron(III) [MAAP-Fe(III)] as metal-chelating monomer has been used to prepare selective molecular imprinted polymer (MIP). MIP film for detection of caffeic acid has been developed on QCM electrode and selectivity experiments and analytical performance of caffeic acid imprinted QCM nanosensor has been studied. The caffeic acid imprinted QCM nanosensor has been characterized by AFM. After the characterization studies, imprinted and non-imprinted nanosensors was connected to QCM system for studies of connection of the target molecule, selectivity and the detection of amount of target molecule in real samples. The detection limit was found to be 7.8 nM. The value of Langmuir constant (b) (4.06 × 10(6)) that was acquired using Langmuir graph demonstrated that the affinity of binding sites was strong. Also, selectivity of prepared caffeic acid imprinted nanosensor was found as being high compared to chlorogenic acid. Finally, the caffeic acid levels in plant materials was determined by the prepared QCM nanosensor.

Synthesis of surface molecularly imprinted nanoparticles for recognition of lysozyme using a metal coordination monomer

Molecularly imprinted polymers against proteins are regarded as promising substitutes for natural antibodies, but have been frustrated with the problems including reduced interaction between functional monomers and protein template in the aqueous media required during their synthesis and restricted mass transfer across the resulting crosslinked polymer matrixes. For addressing these issues, herein we proposed a strategy for imprinting of a protein on the surface of nanoparticles using a metal chelating monomer. With lysozyme as a model protein template and Cu2+ chelating N-(4-vinyl)-benzyl iminodiacetic acid as the coordination monomer along with other monomers, protein imprinted polymer nanoshells were formed over vinyl-modified silica nanoparticles via surface polymerization in high-dilution monomer solution. The feed concentration of the crosslinking monomer was optimized toward achieving the best imprinting effect. Compared with the related imprinted materials reported previously, the resultant core–shell imprinted particles showed greatly faster binding kinetics, elevated rebinding capacity and selectivity. More importantly, noticeably high binding affinity was achieved with an estimated dissociation constant of 4.1×10−8M which is comparable to that of conventional antibodies

Gold–silver-nanoclusters having cholic acid imprinted nanoshell

Molecular imprinted polymers (MIPs) as a recognition element for sensors are increasingly of interest and MIP-nanoparticles have started to appear in the literature. In this study, we have proposed a novel thiol ligand-capping method with polymerizable methacryloylamido-cysteine (MAC) attached to gold–silver-nanoclusters reminiscent of a self-assembled monolayer and have reconstructed surface shell by synthetic host polymers based on molecular imprinting method for cholic acid recognition. In this method, methacryloylamidohistidine–Pt(II) [MAH–Pt(II)] has used as a new metal-chelating monomer via metal coordination–chelation interactions and cholic acid. Nanoshell sensors with templates give a cavity that is selective for cholic acid. The cholic acid can simultaneously chelate to Pt(II) metal ion and fit into the shape-selective cavity. Thus, the interaction between Pt(II) ion and free coordination spheres has an effect on the binding ability of the gold–silver-nanoclusters nanosensor. The binding affinity of the cholic acid imprinted nanoparticles have investigated by using the Langmuir and Scatchard methods and determined affinity constant (Kaffinity) has found to be 2.73×104molL−1 and 2.13×108molL−1, respectively. At the last step of this procedure, cholic acid level in blood serum and urine which belong to a healthy people were determined by the prepared gold–silver-nanoclusters.

Preparation of new molecularly imprinted nanosensor for cholic acid determination

Molecular imprinted polymers (MIPs) as a recognition element for sensors are increasingly of interest and MIP-nanoparticles have started to appear in the literature. In this study, we have proposed a novel thiol ligand-capping method with polymerizable methacryloylamido-cysteine (MAC) attached to gold nanoparticles, reminiscent of a self-assembled monolayer and have reconstructed surface shell by synthetic host polymers based on molecular imprinting method for recognition. In this method, methacryloylamidohistidine-Pt(II) [MAH-Pt(II)] has used as a new metal-chelating monomer via metal coordination–chelation interactions and cholic acid. Nanoshell sensors with templates give a cavity that is selective for cholic acid. The cholic acid can simultaneously chelate to Pt(II) metal ion and fit into the shape-selective cavity. Thus, the interaction between Pt(II) ion and free coordination spheres has an effect on the binding ability of the gold nanoparticles nanosensor. The binding affinity of the cholic acid imprinted nanoparticles has investigated by using the Langmuir and Scatchard methods and determined affinity constant (Kaffinity) were found as 1.48×104molL−1 and 6.59×106molL−1, respectively. At the last step of this procedure, cholic acid level in blood serum and urine which belong to healthy people was determined by the prepared Au nanosensor.

Nanosensors having dipicolinic acid imprinted nanoshell for Bacillus cereus spores detection

Molecular imprinted polymers (MIPs) as a recognition element for sensors are increasingly of interest and MIP nanoclusters have started to appear in the literature. In this study, we have proposed a novel thiol ligand-capping method with polymerizable methacryloylamido-cysteine (MAC) attached to gold–silver nanoclusters, reminiscent of a self-assembled monolayer and have reconstructed surface shell by synthetic host polymers based on molecular imprinting method for recognition. In this method, methacryloylamidoantipyrine–terbium ((MAAP)2–Tb(III)) has been used as a new metal-chelating monomer via metal coordination–chelation interactions and dipicolinic acid (DPA) which is main participant of Bacillus cereus spores used as a model. Nanoshell sensors with templates give a cavity that is selective for DPA. The DPA can simultaneously chelate to Tb(III) metal ion and fit into the shape-selective cavity. Thus, the interaction between Tb(III) ion and free coordination spheres has an effect on the binding ability of the gold–silver nanoclusters nanosensor. The binding affinity of the DPA imprinted nanoclusters has been investigated by using the Langmuir and Scatchard methods, and the respective affinity constants (Kaffinity) determined were found to be 1.43 × 104 and 9.1 × 106 mol L−1.

Gold nanoparticles having dipicolinic acid imprinted nanoshell for Bacillus cereus spores recognition

Taking into account the recognition element for sensors linked to molecular imprinted polymers (MIPs), a proliferation of interest has been witnessed by those who are interested in this subject. Indeed, MIP nanoparticles are theme which recently has come to light in the literature. In this study, we have proposed a novel thiol ligand-capping method with polymerizable methacryloylamidocysteine (MAC) attached to gold nanoparticles, reminiscent of a self-assembled monolayer. Furthermore, a surface shell by synthetic host polymers based on molecular imprinting method for recognition has been reconstructed. In this method, methacryloyl iminodiacetic acid-chrome (MAIDA–Cr(III)) has been used as a new metal-chelating monomer via metal coordination–chelation interactions and dipicolinic acid (DPA) which is the main participant of Bacillus cereus spores has been used as a template. Nanoshell sensors with templates produce a cavity that is selective for DPA. The DPA can simultaneously chelate to Cr(III) metal ion and fit into the shape-selective cavity. Thus, the interaction between Cr(III) ion and free coordination spheres has an effect on the binding ability of the gold nanoparticles nanosensor. The interactions between DPA and MIP particles were studied observing fluorescence measurements. DPA addition caused significant decreases in fluorescence intensity because they induced photoluminescence emission from Au nanoparticles through the specific binding to the recognition sites of the crosslinked nanoshell polymer matrix. The binding affinity of the DPA imprinted nanoparticles has been explored by using the Langmuir and Scatchard methods and the analysis of the quenching results has been performed in terms of the Stern–Volmer equation.

Preparation of new molecularly imprinted quartz crystal microbalance hybride sensor system for 8-hydroxy-2′-deoxyguanosine determination

The routine measurement of 8-hydroxy-2′-deoxyguanosine (8-OHdG) in biological samples is a difficult analytical problem due to the low levels of the analyte and complex matrix. A new 8-OHdG imprinted quartz crystal microbalance (QCM) sensor has been developed for selective determination of 8-OHdG in serum samples. To fulfil the desired results, we have used methacryloyl aminoantipyrine-Fe(III) [MAAP-Fe(III)] and methacryloyl histidine-Pt(II) [MAH-Pt(II)] as metal-chelating monomers via double metal coordination–chelation interactions for the preparation of additional selective molecular imprinted polymers (MIP). The study includes the measurement of binding interaction of 8-OHdG imprinted quartz crystal microbalance (QCM) sensor, selectivity experiments and analytical performance of QCM chip. The obtained results have showed that the application of double metal–chelate monomer systems has been more effective than single metal–chelate monomer systems. In this study, the detection limit and the linear working range were found to be 0.0075 and 0.0100–3.5 μM, respectively. The affinity constant ( K affinity) was found to be 1.54 × 10 5 M −1 for 8-OHdG using MAH-Pt-8-OHdG–MAAP-Fe based thin film. Also, selectivity of prepared QCM sensor was found as being very high in the presence of competitive species. At the last step of this procedure, 8-OHdG level in blood serum which belongs to a intestinal cancer patient was determined by the prepared QCM sensor.

Gold–silver nanoclusters having dipicolinic acid imprinted nanoshell for Bacillus cereus spores recognition

Molecular imprinted polymers (MIPs) as a recognition element for sensors are increasingly of interest and MIP nanoclusters have started to appear in the literature. In this study, we have proposed a novel thiol ligand-capping method with polymerizable methacryloylamidocysteine (MAC) attached to gold–silver nanoclusters, reminiscent of a self-assembled monolayer and have reconstructed surface shell by synthetic host polymers based on molecular imprinting method for recognition. In this method, methacryloyl iminodiacetic acid-chrome (MAIDA-Cr(III)) has been used as a new metal-chelating monomer via metal coordination–chelation interactions and dipicolinic acid (DPA) which is a main participant of Bacillus spores has been used as a template. Nanoshell sensors with templates give a cavity that is selective for DPA. The DPA can simultaneously chelate to Cr(III) metal ion and fit into the shape-selective cavity. Thus, the interaction between Cr(III) ion and free coordination spheres has an effect on the binding ability of the gold–silver nanoclusters nanosensor. The binding affinity of the DPA imprinted nanoclusters has been investigated by using the Langmuir and Scatchard methods and determined affinity constants ( K affinity) were found as 18 × 10 6 mol L −1 and 9 × 10 6 mol L −1, respectively.

8-OHdG sensing with MIP based solid phase extraction and QCM technique

8-Hydroxy-2′-deoxyguanosine (8-OHdG) is one of the most abundant oxidative DNA lesions resulting from reactive oxygen species (ROS). The routine measurement of 8-OHdG in biologic samples is a difficult analytical problem due to the low levels of the analyte and complex matrix. In this study, we have proposed an imprinting method for 8-OHdG recognition and determination by methacryloyl aminoantipyrine-Fe(III) [MAAP-Fe(III)] as a new metal-chelating monomer via metal coordination-chelation interactions. The study includes the solid-phase extraction of blood samples by a new 8-OHdG imprinted sorbent and the measurement of binding interaction of 8-OHdG imprinted quartz crystal microbalance (QCM) sensor via ligand interaction. 8-OHdG imprinted sorbent was prepared by bulk polymerization of MAAP-Fe(III) and N-N′-methylenebisacrylamide. By using a photo-graft surface polymerization technique with irradiation by ultra-violet (UV) light, a thin MIP film was prepared for the detection of 8-OHdG. The determined affinity constant ( K a) were found as 78760 M −1 using 8-OHdG imprinted thin film. The 8-OHdG level in blood serum from a breast cancer patient was determined by the prepared QCM sensor. Lastly, analytical performances of this system was compared with capillary electrophoresis (CE) system.

Synergie between molecular imprinted polymer based on solid-phase extraction and quartz crystal microbalance technique for 8-OHdG sensing

Recently, the 8-hydroxy-2′-deoxyguanosine (8-OHdG) has been used as a marker to determine the oxidative stress. There is no any cheap and easy determination method based on chips and sensor systems for the determination of 8-OHdG. In this study, we have proposed imprinting methods for 8-OHdG recognition and determination using methacryloylamidohistidine-platinum(II) [MAH-Pt(II)] as a new metal-chelating monomer. The study includes the solid-phase extraction (SPE) of blood sample by a new 8-OHdG imprinted sorbent and the measurement of binding interaction of 8-OHdG imprinted quartz crystal microbalance (QCM) sensor via ligand interaction. 8-OHdG imprinted sorbent has prepared by bulk polymerization of MAH-Pt(II) and N- N′-methylenebisacrylamide. 8-OHdG imprinted sensor has prepared on a QCM chip coating the thiol pretreated Au electrode. At the end of these steps, a thin molecular imprinted polymer (MIP) film for the detection of 8-OHdG has developed and analytical performance of QCM sensor which has prepared using MIP was investigated. The affinity constant ( K a) for 8-OHdG using MAH-Pt-based thin film has determined by using the Scatchard method. The average percentage recovery of 8-OHdG from plasma samples was found as 80% by using of 8-OHdG imprinted SPE material. At the last step, 8-OHdG level in several blood plasma has been determined by this improved QCM sensor. The obtained results confirmed that the 8-OHdG level in cancer patient's blood was significantly higher than in general subjects.

Synthesis and polymerizations of new metal chelating monomers from alkyl α‐hydroxymethacrylates

AbstractTwo new diethyl iminodiacetate‐containing monomers (EBMA‐ID and CMAC‐ID) were synthesized through the reaction of ethyl α‐bromomethacrylate (EBMA) and α‐chloromethacryloylchloride (CMAC) with diethyl iminodiacetate (ID). The hydrolysis of the ethyl ester groups with potassium hydroxide gave two chelating monomers with potassium salt of iminodiacetic acid (EBMA‐IDA‐K+ and CMAC‐IDA‐K+). The homopolymerization and copolymerization with 2‐hydroxyethyl methacrylate (HEMA) of EBMA‐ID and CMAC‐ID were investigated by photodifferential scanning calorimetry at 40°C using 2,2′‐dimethoxy‐2‐phenyl‐acetophenone (DMPA) as initiator. The monomers showed very low homopolymerization reactivity which may be attributed to the steric effect of N,N‐disubstituted methacrylamides, the presence of allyl amine group that can undergo degradative chain transfer and the bulky ID group close to the double bond. Also, addition of these monomers to HEMA decreased polymerization rate and conversion with fraction added. EBMA‐IDA‐K+ and CMAC‐IDA‐K+ were copolymerized with acrylamide in water using 2,2′‐azobis(N,N′‐amidinopropane) dihydrochloride (V‐50) initiator. Here also, it was observed that the incorporation of the synthesized monomers into acrylamide reduced both the rate of polymerization and conversion. The copolymers were characterized by 1H‐NMR spectroscopy, thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The UV‐visible and TGA spectra confirmed that the synthesized monomers showed chelating ability for Ni+2 and Cr+3. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Molecularly imprinted ligand-exchange recognition assay of DNA by SPR system using guanosine and guanine recognition sites of DNA

Molecular imprinting polymer (MIP) as a recognition element for sensors are increasingly of interest and MIP-SPR have started to appear in the literature. In this study, we have proposed a novel surface imprinting method for DNA recognition and determination by methacryl-amidohistidine-platinum(II) [MAH-Pt(II)] as a new metal-chelating monomer via metal coordination–chelation interactions and guanosine/guanine templates of DNA. The study includes the measurement of binding interaction of molecular imprinted surface plasmon resonance (SPR) sensor via ligand interaction and recognition selectivity studies of guanosine and guanine imprinted polymers with respect to guanine and dsDNA. Adsorption isotherms of adenosine, guanosine, guanine, adenine, ssDNA and dsDNA were plotted and affinity constants for guanosine and guanine imprinted films were also calculated.

Quantum dot nanocrystals having guanosine imprinted nanoshell for DNA recognition

Molecular imprinted polymers (MIPs) as a recognition element for sensors are increasingly of interest and MIP nanoparticles have started to appear in the literature. In this study, we have proposed a novel thiol ligand-capping method with polymerizable methacryloylamido-cysteine (MAC) attached to CdS quantum dots (QDs), reminiscent of a self-assembled monolayer and have reconstructed surface shell by synthetic host polymers based on molecular imprinting method for DNA recognition. In this method, methacryloylamidohistidine-platinium (MAH-Pt(II)) is used as a new metal-chelating monomer via metal coordination-chelation interactions and guanosine templates of DNA. Nanoshell sensors with guanosine templates give a cavity that is selective for guanosine and its analogues. The guanosine can simultaneously chelate to Pt(II) metal ion and fit into the shape-selective cavity. Thus, the interaction between Pt(II) ion and free coordination spheres has an effect on the binding ability of the CdS QD nanosensor. The binding affinity of the guanosine imprinted nanocrystals has investigated by using the Langmuir and Scatchard methods, and experiments have shown the shape-selective cavity formation with O6 and N7 of a guanosine nucleotide ( K a = 4.841 × 10 6 mol L −1) and a free guanine base ( K a = 0.894 × 10 6 mol L −1). Additionally, the guanosine template of the nanocrystals is more favored for single stranded DNA compared to double stranded DNA.