In this work, we report the development of an ultrasensitive sandwich-type electrochemical aptasensor for protein detection. The aptasensor is fabricated by using nitrogen-doped graphene oxide (N-GO) and Au nanoparticles (AuNPs) as sensing substrates, molybdenum disulfide (MoS) spheres as the hybridization chain reaction (HCR) platform, and thrombin as the model protein. When the hybridization reaction is initiated through two biotinylated hairpin probes, vast horseradish peroxidases are immobilized on the long duplex by the biotin-avidin reaction.
View Article and Find Full Text PDFAn ultrasensitive sandwich-type electrochemical biosensor for DNA detection is developed based on spherical silicon dioxide/molybdenum selenide (SiO@MoSe) and graphene oxide-gold nanoparticles (GO-AuNPs) hybrids as carrier triggered Hybridization Chain Reaction (HCR) coupling with multi-signal amplification. The proposed sensoring assay utilizes a spherical SiO@MoSe/AuNPs as sensing platform and GO-AuNPs hybrids as carriers to supply vast binding sites. HO+HQ system is used for DNA detection and HCR as the signal and selectivity enhancer.
View Article and Find Full Text PDFAn ultrasensitive electrochemical biosensor for detecting microRNAs is fabricated based on hollow molybdenum disulfide (MoS) microcubes. Duplex-specific nuclease, enzyme and electrochemical-chemical-chemical redox cycling are used for signal amplification. Hollow MoS microcubes constructed by ultrathin nanosheets are synthesized by a facile template-assisted strategy and used as supporting substrate.
View Article and Find Full Text PDFAn ultrasensitive electrochemical biosensor for microRNA (miRNA) is developed based on tungsten oxide-graphene composites coupling with catalyzed hairpin assembly target recycling and enzyme signal amplification. WO3-Gr is prepared by a simple hydrothermal method and then coupled with gold nanoparticles to act as a sensing platform. The thiol-terminated capture probe H1 is immobilized on electrode through Au-S interaction.
View Article and Find Full Text PDFA 2-dimensional tungsten disulfide-acetylene black (WS-AB) composite is synthesized by a simple hydrothermal method to achieve excellent electrochemical properties for applications as a DNA biosensor. The biosensor is fabricated based on the Au nanoparticles (AuNPs) and WS-AB composite modified electrode, which subsequently is used to couple with a capture probe by an Au-S bond, then modified with target DNA, auxiliary DNA and bio-H1-bio-H2 (H1-H2) to perform hybridization chain reaction for signal amplification. Herein, two DNA hairpins H1 and H2 are opened by the recognition probe.
View Article and Find Full Text PDFA highly sensitive and ultrasensitive electrochemical aptasensor for platelet-derived growth factor BB (PDGF-BB) detection is fabricated based on layered molybdenum selenide-graphene (MoSe2-Gr) composites and Exonuclease III (Exo III)-aided signal amplification. MoSe2-Gr is prepared by a simple hydrothermal method and used as a promising sensing platform. Exo III has a specifical exo-deoxyribonuclease activity for duplex DNAs in the direction from 3' to 5' terminus, however its activity is limited on the duplex DNAs with more than 4 mismatched terminal bases at 3' ends.
View Article and Find Full Text PDF