A novel electrochemical hydrogen peroxide (HO) sensor based on Cu-porphyrin(Cu-TCPP)/G-quadruplex-hemin nanocomposite was constructed by assembling two-dimensional Cu-TCPP metal-organic framework (MOF) nanofilm and G-quadruplex-hemin DNAzyme. The Cu-TCPP synthesized by the surfactant-assisted method has a wrinkled two-dimensional nanofilm morphology, which gives it a large surface area and accessible active sites. Cu-TCPP exhibits peroxidase activity and good stability and can catalyze the reduction of HO. In addition, Cu-TCPP can be used as a nanocarrier for G-quadruplex-hemin DNAzyme with strong peroxidase activity to achieve "biological barcode" amplification and improve stability. The cooperative interaction of Cu-TCPP and G-quadruplex-hemin DNAzyme effectively amplifies the electrochemical response signal. Electrochemical studies have shown that the constructed sensor exhibits good electrochemical sensing performance with three linear ranges: 0.08 μM to 0.11 mM, 0.11-0.91 mM, and 0.91-8.1 mM, with sensitivities of 2315.86, 301.00, and 65.71 μA/(mM cm), respectively, and the detection limit was 0.03 μM. In addition, the sensor shows good selectivity. In summary, this study provides a simple and effective new strategy for electrochemical sensing based on two-dimensional MOFs and artificial enzymes.
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http://dx.doi.org/10.1021/acsami.0c09254 | DOI Listing |
Anal Chem
January 2025
State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, PR China.
The development of intelligent nanotheranostic technology that integrates diagnostic and therapeutic functions holds great promise for personalized nanomedicine. However, most of the nanotheranostic agents exhibit "always-on" properties and do not involve an amplification step, which may largely limit imaging contrast and restrict therapeutic efficacy. Herein, we construct a novel nanotheranostic platform (Hemin/DHPs/PDA@CuS nanocomposite) by assembling DNA hairpin probes (DHPs) and hemin on the surface of PDA@CuS nanosheets that enables amplified fluorescence imaging and activatable chemodynamic therapy (CDT) of tumors.
View Article and Find Full Text PDFMikrochim Acta
January 2025
Department of General Surgery, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, 758 Hefei Road, Qingdao, Shandong, 266035, P.R. China.
A self-powered dual-electrode aptasensor was developed for the detection of tumor marker carcinoembryonic antigen (CEA). The composite BiVO/ZnInS, which is capable of forming a Z-scheme heterojunction, was chosen as the photoanode, and the AuNP/CuBiO complex was chosen as the photocathode in photoelectrochemical (PEC) detection. The experiments showed that the constructed self-powered dual-electrode system had a good photoelectric response to white light, and the photocurrent signal of the photocathode was significantly enhanced under the influence of the photoanode.
View Article and Find Full Text PDFNucleic Acids Res
December 2024
Department of Emergency Medicine, Stanford University, 240 Pasteur Drive Rm 0300 Stanford, CA 94305, USA.
The mechanisms of bacterial killing by neutrophil extracellular traps (NETs) are unclear. DNA, the largest component of NETs was believed to merely be a scaffold with antimicrobial activity only through the charge of the backbone. Here, we demonstrate for the first time that NETs DNA is beyond a mere scaffold to trap bacteria and it produces hydroxyl free radicals through the spatially concentrated G-quadruplex/hemin DNAzyme complexes, driving bactericidal effects.
View Article and Find Full Text PDFTalanta
December 2024
State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China. Electronic address:
Herein, we present a colorimetric sensing strategy for the identification and quantification of tumor-associated miRNAs based on dual DNAzyme amplification. In this sensing ensemble, the substrate portion of the Pb-dependent 8-17 DNAzyme combines with the G-quadruplex portion to form a hairpin substrate strand. The two split 8-17 DNAzyme strands are partially complementary to the substrate strand and serve as a recognition unit for binding the target miRNA.
View Article and Find Full Text PDFMikrochim Acta
December 2024
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, People's Republic of China.
A novel detection technique is introduced that offers sensitive and reliable ochratoxin A (OTA) detection. The method leverages the etching of gold nanorods (AuNRs) stabilized by hexadecyl trimethyl ammonium bromide (CTAB) using the oxidized form of 3,3',5,5'-tetramethyl benzidine sulfate (TMB), creating a susceptible multicolor visual detection system for OTA. The visual detection is enabled by Mg-assisted DNAzyme catalysis combined with the catalytic hairpin assembly (CHA) signal amplification strategy.
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