A new approach for easy synthesis of Bacillus pseudomycoides immobilized polyvinyl alcohol (PVA)/glutaraldehyde (GA) hydrogel for application in a wastewater treatment system is reported. Optimization studies revealed that GA/PVA mass ratio of 0.03 and acidic pH of 2 were required for hydrogel synthesis and eventually for bacterial cell immobilization.
View Article and Find Full Text PDFA novel One MoNomer dual imprinted graphene oxide/carbon black composite polymer was developed applying 'surface-grafting from' approach on the screen printed carbon electrode for the electrochemical sensing of dopamine and epinephrine. Acryloylated-graphene oxide/carbon black was synthesized for the first time. This served both as a crosslinker and monomer leading to the fast electron transfer from the redox centre to the electrode.
View Article and Find Full Text PDFIn this work, a nanohybrid-based imprinted polymer consisting of N-doped hollow carbon nanospheres and palladium is reported for the electroanalysis of ultratrace level of anticancer drug, 6-mercaptopurine, used in the treatment of leukemia. For this, N-doped carbon nanospheres decorated with palladium were first developed, and subsequently, a molecular imprinted polymer layer was grown onto their surfaces. The so-produced silica-embedded nanocomposite was made hollow by etching silica moieties with hydrofluoric acid.
View Article and Find Full Text PDFA novel molecularly imprinted polymer-capped acrylated nitrogen doped graphene quantum dots and bimetallic Au/Ag core-shell was synthesized to serve as a sensing nano-hybrid film for the detection of an anticancerous drug, hydroxyurea. This exploited the use of a functionalized nitrogen doped graphene quantum dots iniferter. This initiated the polymerization, following "surface grafting-from" approach, over the surface of a screen-printed carbon electrode to obtain requisite stability and selectivity of the measurement.
View Article and Find Full Text PDFThe present work describes a new, simple, and easy method of generating acrylamide functionalised reduced graphene oxide-fullerene layer-by-layer assembled dual imprinted polymers to quantify D- and L-Serine at ultra trace level in aqueous and real samples. Herein, the pencil graphite electrode was initially spin coated with D-Serine imprinted acrylamide functionalized reduced graphene oxide. After 10 min thermal treatment (50 °C), this electrode was again modified with L-Serine imprinted acrylamide functionalized fullerene molecules.
View Article and Find Full Text PDFDouble layered one-by-one imprinted hollow core-shells@ pencil graphite electrode was fabricated for sequential sensing of anti-HIV drugs. For this, two eccentric layers were developed on the surface of vinylated silica nanospheres to obtain double layered one-by-one imprinted solid core-shells. This yielded hollow core-shells on treatment with hydrofluoric acid.
View Article and Find Full Text PDFA new ultra sensing molecularly imprinted polymer beads modified pencil graphite electrode was fabricated, with the help of the inverse suspension polymerization technique, for ascertaining the adequate supplementation of dacarbazine in the cancer treatment. The inverse suspension polymerization technique was beneficial in obtaining surface imprinted polymer-based electrocatalytic nanospheres with narrow size distribution. These nanospheres were found to be superior to the corresponding microspheres and planar films, in terms of electrode kinetics and sensitivity, with the differential pulse anodic stripping voltammetric transduction.
View Article and Find Full Text PDFA novel water-compatible C-monoadduct based imprinted micelles was synthesized by the self-assembly of vinylic-C-monoadduct with sodium dodecylsulfate micellar system, in the presence of chlorambucil as a model template (anticancer drug). After template retrieval with acetonitrile, these imprinted micelles were immobilized at the surface of ionic liquid decorated carbon ceramic electrode. Herein, C-monoadduct (the head group of micelle) actually served as a nanomediator for electronic transmission across multiple interfaces.
View Article and Find Full Text PDFThis paper reports a typical synthesis of a nanocomposite of functionalized graphene quantum dots and imprinted polymer at the surface of screen-printed carbon electrode using N-acryloyl-4-aminobenzamide, as a functional monomer, and an anticancerous drug, ifosfamide, as a print molecule (test analyte). Herein, graphene quantum dots in nanocomposite practically induced the electrocatalytic activity by lowering the oxidation overpotential of test analyte and thereby amplifying electronic transmission, without any interfacial barrier in between the film and the electrode surface. The differential pulse anodic stripping signal at functionalized graphene quantum dots based imprinted sensor was realized to be about 3- and 7-fold higher as compared to the traditionally made imprinted polymers prepared in the presence and the absence of graphene quantum dots (un-functionalized), respectively.
View Article and Find Full Text PDFThe most important objectives that are frequently found in bio-analytical chemistry involve applying tools to relevant medical/biological problems and refining these applications. Developing a reliable sample preparation step, for the medical and biological fields is another primary objective in analytical chemistry, in order to extract and isolate the analytes of interest from complex biological matrices. Since, main inborn errors of metabolism (IEM) diagnosable through uracil analysis and the therapeutic monitoring of toxic 5-fluoruracil (an important anti-cancerous drug) in dihydropyrimidine dehydrogenase deficient patients, require an ultra-sensitive, reproducible, selective, and accurate analytical techniques for their measurements.
View Article and Find Full Text PDFThe present work describes a new, simple and easy method for the generation of novel molecularly imprinted polymer-based nanoarrays with uracil and 5-fluorouracil as template(s) on the surface of a silver electrode. The procedure involved electrochemical etching of silver-wire to develop nanopores on its tip. In these nanopores, a prepolymer mixture with template(s) was filled-in via spin coating and subjected to free radical thermal polymerization.
View Article and Find Full Text PDFA typical, reproducible, and rugged screen printed carbon electrode, modified with dual-ion imprinted beads, was fabricated employing the "surface grafting from" approach. For this, the acyl chloride functionalized magnetic nanoparticles were first immobilized and chemically attached with a typical functional monomer (but-2-enedioic acid bis-[(2-amino-ethyl)-amide]) on the electrode surface. This was subsequently subjected to the thermal polymerization in the presence of template ions (Ce(IV) and Gd(III)), cross-linker (ethylene glycol dimethacrylate), initiator (AIBN), and multiwalled carbon nanotubes.
View Article and Find Full Text PDFA rapid, selective, and sensitive double-template imprinted polymer nanofilm-modified pencil graphite electrode was fabricated for the simultaneous analysis of phosphorus-containing amino acid-type herbicides (glyphosate and glufosinate) in soil and human serum samples. Since both herbicides respond overlapped oxidation peaks and only glyphosate is prone to nitrosation, n-nitroso glyphosate and glufosinate were used as templates for obtaining the well-resolved quantitative differential pulse anodic stripping voltammetric peaks on the proposed sensor. Toward sensor fabrication, a nano-structured polymer film was first grown directly on the electrode via initial immobilization of gold nanoparticles at its surface.
View Article and Find Full Text PDFMolecularly imprinted micro-solid phase extraction fiber was developed by modifying molecularly imprinted polymer film on the surface of silica fiber exploring "grafting via surface attached monomer" (method I) and "grafting via sol-gel" (method II) approaches. The latter approach was found to be inferior to the former one in terms of the sensitivity of insulin detection [method I, LOD=0.009ngmL(-1); method II, LOD=0.
View Article and Find Full Text PDFIn simultaneous determination of group of elements, there are inter-metallic interactions which result in a non-linear relationship between the peak current and ionic concentration for each of the element, at bare (unmodified) electrode. To resolve this problem, we have resorted, for the first time, to develop a modified pencil graphite electrode using a typical ion imprinted polymer network (dual-ion imprinted polymer embedded in sol-gel matrix (inorganic-organic hybrid nano-material)) for the simultaneous analysis of a binary mixture of Cd(II) and Cu(II) ions, without any complication of inter-metallic interactions and competitive bindings, in real samples. The adequate resolution of differential pulse anodic stripping voltammetry peaks by 725 mV (cf, 615 mV with unmodified electrode), without any cross-reactivity and the stringent detection limits as low as, 0.
View Article and Find Full Text PDFA simple hyphenation approach was adopted to obtain a new molecularly imprinted micro solid-phase extraction fiber (as a selective extraction tool) and complementary molecularly imprinted polymer coated pencil graphite electrode (as a detection tool) for the selective and sensitive analysis of epinephrine, which is a disease biomarker prevalent at ultra trace level in biological fluids. In both extraction and detection processes, the functionalized multiwalled carbon nanotubes (CNT-mers) were preferred to multiwalled carbon nanotubes (unmodified) in order to obtain a stable homogeneously dispersed imprinted polymer matrix of better electroconductivity and adsorptive characteristics. The hyphenation of both tools helped dual pre-concentration of epinephrine so as to achieve the stringent limit [limit of detection: 0.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
October 2013
A new molecularly imprinted polymer-matrix (titanium dioxide nanoparticle/multiwalled carbon nanotubes) nanocomposite was developed for the modification of pencil graphite electrode as an enantioselective sensing probe for aspartic acid isomers, prevalent at ultra trace level in aqueous and real samples. The nanocomposite having many shape complementary cavities was synthesized adopting surface initiated-activators regenerated by electron transfer for atom transfer radical polymerization. The proposed sensor has high stability, nanocomposite uniformity, good reproducibility, and enhanced electrocatalytic activity to respond oxidative peak current of L-aspartic acid quantitatively by differential pulse anodic stripping voltammetry, without any cross-reactivity in real samples.
View Article and Find Full Text PDFA dual-template imprinted polymer film containing dispersed multiwalled carbon nanotubes was exploited in the fabrication of a typical, reproducible, and rugged carbon ceramic electrode, adopting "surface grafting from" approach for the growth of a nanometer thin coating on its surface. For this, chloro groups were first introduced at the exterior surface of silica-carbon composite electrode through sol-gel modification using (3-chloropropyl)-trimethoxysilane, followed by an iniferter (sodium diethyl dithiocarbamate) initiated photopolymerization of functional monomer (2,4,6-trisacrylamido-1,3,5-triazine), mixed templates (ascorbic acid and dopamine), and cross-linker (ethylene glycol dimethacrylate), in the presence of multiwalled carbon nanotubes. The modified sensor was validated for the simultaneous analysis of ascorbic acid and dopamine in aqueous, blood serum, cerebrospinal fluid, and pharmaceutical samples, using differential pulse anodic stripping voltammetric technique.
View Article and Find Full Text PDFA novel molecularly imprinted polymer, selective for human hemoglobin, was immobilized on the surface of CdS quantum dots-multiwalled carbon nanotubes nanoconjugate-modified pencil graphite electrode. The fabricated sensor was found to be water-compatible and biologically benign, since the molecular imprinting was exclusively carried out in water, without any protein denaturation and electrode fouling. Notably, the pencil graphite electrode modified with merely a nanoconjugate matrix might involve the onset possibilities of electrode passivation and protein denaturation.
View Article and Find Full Text PDFCarbon-nanotubes play a pivotal role in molecularly imprinted polymer technology for inculcating conducting property, high surface to volume ratio, and maximum porosity in the film texture. Contrary to the non-covalent heterogeneous dispersion of pure (unmodified) multiwalled carbon nanotubes in the imprinted polymer film, the homogeneous distribution of their functionalized derivative was found more effective to augment the sensitivity of the measurement. This could be made feasible using multiwalled carbon nanotubes bearing terminal monomeric unit (termed as "CNT-mer") for the polymerization (one CNT-mer in each repeating unit).
View Article and Find Full Text PDFThis paper reports a combination of molecularly imprinted stir bar sorptive extraction and complementary molecularly imprinted polymer-sensor for the analysis of dopamine as a biomarker of several neurodegenerative diseases occurred at ultra trace level. This exploited iniferter initiated polymerization via "surface grafting-from" approach onto magnetic stir bar (for sorptive extraction) and multiwalled carbon nanotubes-ceramic electrode (for detection). Such hyphenation helped dual pre-concentration of dopamine in aqueous, biological and pharmaceutical samples.
View Article and Find Full Text PDFThe present work is related to combination of molecularly imprinted solid-phase microextraction and complementary molecularly imprinted polymer-sensor. The molecularly imprinted polymer grafted on titanium dioxide modified silica fiber was used for microextraction, while the same polymer immobilized on multiwalled carbon nanotubes/titanium dioxide modified pencil graphite electrode served as a detection tool. In both cases, the surface initiated polymerization was found to be advantageous to obtain a nanometer thin imprinted film.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
March 2013
In this study, both experimental and theoretical vibrational spectra of template (hydroxyurea, HU), monomer (N-(4,6-bisacryloyl amino-[1,3,5] triazine-2-yl-)-acryl amide, TAT), and HU-TAT complexes were compared and these were respectively found to be in good agreement. Binding energies of HU, when complexed with different monomers, were computed using second order Moller Plesset theory (MP2) at 6-311++G(d,p) level both in the gas as well as solution phases. HU is an antineoplastic agent extensively being used in the treatment of polycythaemia Vera and thrombocythemia.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
January 2013
An alternative method is presented for the modification of pencil graphite fibers using surface imprinting technology. In this new approach, we have adopted surface initiated electropolymerization of benzidine monomer, with simultaneous imprinting of template (d- and l-methionine), on carboxylated multiwalled carbon nanotubes anchored pencil graphite fiber. This yielded a nanostructured ultrathin imprinted film (58.
View Article and Find Full Text PDFThis study describes the synthesis of a new class of substrate-selective molecularly imprinted polymer. This involved tetraethylene glycol 3-morpholin propionate acrylate (functional monomer) and bovine serum albumin (template) for polymerization in aqueous condition, using "surface grafting-from" approach directly on a vinyl exposed multiwalled carbon nanotubes-ceramic electrode. The analyte recapture at pH 6.
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