The authors have prepared suprameolecular systems of chiral Schiffbase ZnAZSB (Zn(II) complexes with azo-groups) or without ZnSB (azo-groups) and colloidal AuNP (gold nanoparticles) of 10, 40 and 80 nm diamete...The authors have prepared suprameolecular systems of chiral Schiffbase ZnAZSB (Zn(II) complexes with azo-groups) or without ZnSB (azo-groups) and colloidal AuNP (gold nanoparticles) of 10, 40 and 80 nm diameters. They exhibited gradual shifts of surface plasmon bands as well as fluorescence bands. The authors observed and discussed induced CD bands on gold nanoparticles from chiral ZnAZSB or ZnSB. Absence of cis-trans photoisomerization of ZnAZSB with AuNP also supported direct contact near the surface of AuNP. Quenching and splitting of fluorescence bands of ZnSB (λex = 550 nm and λem = 400 nm) depending on concentration of ZnSB and size of AuNP also suggested intermolecular (electric) interaction on the surface of AuNE Decrease of the intensity of the CD band around 380 nm resulted from reciprocal induced CD effect due to parallel arrangement of electric transition moments of ZnAZSB or ZnSB and surface of AuNP.展开更多
A novel electrogenerated chemiluminescence (ECL) aptasensor for highly sensitive detection of thrombin was developed on the basis of poly(pyrrole-co-pyrrole propylic acid) nanoparticles loaded with aptamer and rut...A novel electrogenerated chemiluminescence (ECL) aptasensor for highly sensitive detection of thrombin was developed on the basis of poly(pyrrole-co-pyrrole propylic acid) nanoparticles loaded with aptamer and ruthenium complex. Thrombin binding aptamers served as the molecular recognition elements and ruthenium bis(2,2'-bipyridine) (2,2'-bipyridine-4,4'-dicarboxylic acid)-ethylenediamine (Rul) was used as an ECL signal complex. Novel electroactive polymers poly(pyrrole-co-pyr- role propylic acid) nanoparticles (Ppy-pa NPs) were synthesized by a simple alcohol-assisted microemulsion polymerization. Rul-Ppy-pa NPs were synthesized by covalently coupling Rul with the Ppy-pa NPs. Ppy-pa NPs and Rul-Ppy-pa NPs were characterized using a fourier transform infrared spectrometer, super-conducting fourier digital NMR spectrometer, and trans- mission electron microscope. One ECL chemical sensor fabricated by immobilizing the Rul-Ppy-pa NPs on PIGE was developed for the determination of TprA with a high sensitivity and stability. The ECL aptasensor was fabricated by covalenfly coupling the thrombin binding aptamer-I (TBA-I) onto the surface of the paraffin-impregnated graphite electrode, which had been covalently modified with a monolayer of 4-aminobenzene sulfonic acid via electrochemical oxidations, for capturing thrombin onto the electrode and then the TBA-II labeled with Rul-Ppy-pa NPs was bound with epitope of thrombin. The ECL aptasensot showed an extremely low detection limit of 3.0×10^-16 mol/L for thrombin and a good selectivity. This work demonstrated that using Ppy-pa NPs as a carrier of ruthenium complex and molecular recognition element was a promising approach for the fabrication of ECL biosensor with high sensitivity.展开更多
文摘The authors have prepared suprameolecular systems of chiral Schiffbase ZnAZSB (Zn(II) complexes with azo-groups) or without ZnSB (azo-groups) and colloidal AuNP (gold nanoparticles) of 10, 40 and 80 nm diameters. They exhibited gradual shifts of surface plasmon bands as well as fluorescence bands. The authors observed and discussed induced CD bands on gold nanoparticles from chiral ZnAZSB or ZnSB. Absence of cis-trans photoisomerization of ZnAZSB with AuNP also supported direct contact near the surface of AuNP. Quenching and splitting of fluorescence bands of ZnSB (λex = 550 nm and λem = 400 nm) depending on concentration of ZnSB and size of AuNP also suggested intermolecular (electric) interaction on the surface of AuNE Decrease of the intensity of the CD band around 380 nm resulted from reciprocal induced CD effect due to parallel arrangement of electric transition moments of ZnAZSB or ZnSB and surface of AuNP.
基金supported by the National Natural Science Foundation of China (21027007, 20975065 & 20775046)
文摘A novel electrogenerated chemiluminescence (ECL) aptasensor for highly sensitive detection of thrombin was developed on the basis of poly(pyrrole-co-pyrrole propylic acid) nanoparticles loaded with aptamer and ruthenium complex. Thrombin binding aptamers served as the molecular recognition elements and ruthenium bis(2,2'-bipyridine) (2,2'-bipyridine-4,4'-dicarboxylic acid)-ethylenediamine (Rul) was used as an ECL signal complex. Novel electroactive polymers poly(pyrrole-co-pyr- role propylic acid) nanoparticles (Ppy-pa NPs) were synthesized by a simple alcohol-assisted microemulsion polymerization. Rul-Ppy-pa NPs were synthesized by covalently coupling Rul with the Ppy-pa NPs. Ppy-pa NPs and Rul-Ppy-pa NPs were characterized using a fourier transform infrared spectrometer, super-conducting fourier digital NMR spectrometer, and trans- mission electron microscope. One ECL chemical sensor fabricated by immobilizing the Rul-Ppy-pa NPs on PIGE was developed for the determination of TprA with a high sensitivity and stability. The ECL aptasensor was fabricated by covalenfly coupling the thrombin binding aptamer-I (TBA-I) onto the surface of the paraffin-impregnated graphite electrode, which had been covalently modified with a monolayer of 4-aminobenzene sulfonic acid via electrochemical oxidations, for capturing thrombin onto the electrode and then the TBA-II labeled with Rul-Ppy-pa NPs was bound with epitope of thrombin. The ECL aptasensot showed an extremely low detection limit of 3.0×10^-16 mol/L for thrombin and a good selectivity. This work demonstrated that using Ppy-pa NPs as a carrier of ruthenium complex and molecular recognition element was a promising approach for the fabrication of ECL biosensor with high sensitivity.