03121nas a2200253   4500008004100000022001400041245011400055210006900169260007100238300001600309490000600325520221300331653002102544653001702565653000802582653002102590653002502611100001902636700002002655700002102675700002002696700002202716856012902738       2014                        eng d  a1944-824400aFe-TAML encapsulated inside mesoporous silica nanoparticles as peroxidase mimic: femtomolar protein detection0 aFeTAML encapsulated inside mesoporous silica nanoparticles as pe  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG  a13866-138730 v63 a<p>Peroxidase, such as horseradish peroxidase (HRP), conjugated to antibodies are routinely used for the detection of proteins via an ELISA type assay in which a critical step is the catalytic signal amplification by the enzyme to generate a detectable signal. Synthesis of functional mimics of peroxidase enzyme that display catalytic activity which far exceeds the native enzyme is extremely important for the precise and accurate determination of very low quantities of proteins (fM and lower) that is necessary for early clinical diagnosis. Despite great advancements, analyzing proteins of very low abundance colorimetrically, a method that is most sought after since it requires no equipment for the analysis, still faces great challenges. Most reported HRP mimics that show catalytic activity greater than native enzyme (similar to 40-fold) are based on metal/metal-oxide nanoparticles such as Fe3O4. In this paper, we describe a second generation hybrid material developed by us in which approximately 25 000 alkyne tagged biuret modified Fetetraamido macrocyclic ligand (Fe-TAML), a very powerful small molecule synthetic HRP mimic, was covalently attached inside a 40 nm mesoporous silica nanopartide (MSN). Biuret-modified Fe-TAMLs represent one of the best small molecule functional mimics of the enzyme HRP with reaction rates in water close to the native enzyme and operational stability (pH, ionic strength) far exceeding the natural enzyme. The catalytic activity of this hybrid material is around 1000-fold higher than that of natural HRP and 100-fold higher than that of most metal/metal oxide nanoparticle based HRP mimics reported to date. We also show that using antibody conjugates of this hybrid material it is possible to detect and, most importantly, quantify femtomolar quantities of proteins colorimetrically in an ELISA type assay. This represents at least 10-fold higher sensitivity than other colorimetric protein assays that have been reported using metal/metal oxide nanoparticles as HRP mimic. Using a human IgG expressing cell line, we were able to demonstrate that the protein of interest human IgG could be detected from a mixture of interfering proteins in our assay.</p>10acolorimetrically10aimmuno assay10aMSN10aperoxidase mimic10asignal amplification1 aKumari, Sushma1 aDhar, Basab, B.1 aPanda, Chakadola1 aMeena, Abhishek1 aGupta, Sayam, Sen  uhttps://library.ncl.res.in/content/fe-taml-encapsulated-inside-mesoporous-silica-nanoparticles-peroxidase-mimic-femtomolar-001414nas a2200229   4500008004100000022001400041245010000055210006900155260007100224300001400295490000800309520056500317100001800882700002200900700002100922700001800943700002600961700002600987700002001013700002201033856012901055       2014                        eng d  a0002-786300aFormation of a room temperature stable Fe-V(O) complex: reactivity toward unactivated C-H bonds0 aFormation of a room temperature stable FeVO complex reactivity t  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL  a9524-95270 v1363 a<p>An Fe-V(O) complex has been synthesized from equimolar solutions of (Et4N)(2)[Fe-III(Cl)(biuretamide)] and mCPBA in CH3CN at room temperature. The Fe-V(O) complex has been characterized by UV-vis, EPR, Mossbauer, and HRMS and shown to be capable of oxidizing a series of alkanes having C-H bond dissociation energies ranging from 99.3 kcal mol(-1) (cyclohexane) to 84.5 kcal mori (cumene). Linearity in the Bell-Evans-Polayni graph and the finding of a large kinetic isotope effect suggest that hydrogen abstraction is engaged the rate-determining step.</p>1 aGhosh, Munmun1 aSingh, Kundan, K.1 aPanda, Chakadola1 aWeitz, Andrew1 aHendrich, Michael, P.1 aCollins, Terrence, J.1 aDhar, Basab, B.1 aGupta, Sayam, Sen  uhttps://library.ncl.res.in/content/formation-room-temperature-stable-fe-vo-complex-reactivity-toward-unactivated-c-h-bonds-0