Search

It is shown that the aligned electrospun fibers are a convenient platform for studying the mechanical effects on nanomaterials, particularly when using surface‐enhanced Raman scattering as a sensitive tool of monitoring. The ligands on the surface of the embedded Au nanoparticles fall off easily with the shear force from the stretching, in contrast to the counterparts protected by polymer/silica shells. Upon stretching, the chains of Au nanoparticles will reversibly break, as revealed by the dramatic changes in the longitudinal plasmon absorption. It is believed that such a platform will open a window for understanding mechanical effects at the nanoscale, and also a new means for synthetic control. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (GNPs) have thermotherapy effect on several kinds of solid tumors under the irradiation of near infrared light (NIR). It is caused by localized surface plasmon resonance (LSPR). In this study, we discovered a novel phenomenon accompanied with LSPR. Aurothioglucose, a gold ion complex drug, can be formed and released from thioglucose-loaded gold nanoparticles (S-glc-GNPs) by NIR irradiation. It has not been noticed by other researchers before we discovered it. The formation and releasing of aurothioglucose from S-glc-GNPs after NIR irradiation was confirmed via high resolution mass spectrometry. Due to the anti-cancer effect of aurothioglucose, S-glc-GNPs displayed a combined anti-cancer effect of thermotherapy and chemotherapy in cell experiment. Because NIR irradiation is the only switch for the drug release, it could be expected that S-glc-GNPs would have no risk of uncontrollable aurothioglucose burst release and leakage without NIR irradiation. [ABSTRACT FROM AUTHOR]

The widespread use of antibiotics can lead to residues in the environment and food, which in turn affects health problems. The detection of antibiotic residues is urgent. In this work, an efficient and sensitive ampicillin (AMP) electrochemical ensemble sensor was prepared by electrostatic spinning synthesis of Bi 2 O 3 nanomaterials combined with Au nanoparticles. Based on the detection results of differential pulse voltammetry (DPV), it was found that the peak current becomes smaller when the concentration of AMP is continuously increased, and shows a good linear relationship with the logarithm of AMP concentration. By optimizing the experimental conditions, the detection range of Bi 2 O 3 @Au@Apta sensor was from 1 nM to 10 mM with a detection limit of 0.88 nM, and the R2 was as high as 0.9914, with good selectivity, reproducibility and stability. When other interfering substances such as antibiotics and amino acids were added, AMP detection was almost unaffected and the sensor remained highly stable over 7 days. In addition, the Bi 2 O 3 @Au@Apta based electrochemical sensor can be used to determine AMP in real samples (tap water and milk). [Display omitted] • Regular Bi 2 O 3 nanofibers were synthesized by electrospinning method. • The electrochemical biosensor has good selectivity and the detection limit can reach 0.88 nM. • The aptamer sensor can efficiently and sensitively detect ampicillin in water and milk samples. [ABSTRACT FROM AUTHOR]

A highly efficient electrochemical aptamer sensor for the detection of tetracycline (TC) was prepared by using SnC@Au@Apta. Metal tin has good electrochemical activity and high conductivity. It is often used as an electrochemical sensing material. The nanofibers prepared by electrospinning machine make the metal distribution more uniform, not easy to agglomerate, and have a certain porosity, which can improve the sensitivity of sensor detection. Carbonization further enhances conductivity. The gold nanoparticles (AuNPs) on the surface of SnC nanomaterials improve the electrochemical detection performance, and also act as the binding site of the TC aptamer, which is stably combined with the thiol group at the end of the TC aptamer. The TC aptamer specifically binds to TC to detect TC in the sample. The electrochemical performance of SnC@Au@Apta was evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under the optimal conditions, the detection range of SnC@Au@Apta is wide (0.001–100 μM), the detection limit is low (0.83 nM), and it has excellent selectivity, stability and reproducibility. In addition, SnC@Au@Apta can be used to detect TC in milk samples. [Display omitted] • Sn fibers were prepared by electrospinning and carbonized into SnC fibers, maintaining a complete fiber morphology. • SnC@Au as a substrate can be combined with aptamers for specific detection of antibiotics. • The aptamer sensor can efficiently and sensitively detect tetracycline in milk. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu 2 O octahedron with regular morphology was successfully synthesized by hydrothermal method. • Cu 2 O can be used as a nanocarrier to accommodate a large number of aptamers to identify and capture targets. • It has been successfully applied to the detection of tetracycline in actual sample milk. In this work, A novel label-free electrochemical biosensor based on octahedral Cu 2 O @ Au nanocomposites was developed for the detection of tetracycline. The gold nanoparticles (AuNPs) on the surface of Cu 2 O nanomaterials not only improve the electrochemical performance, but also can be used as a binding site for thiol-modified tetracycline aptamers, which can specifically bind to tetracycline. Cu 2 O @ Au nanocomposites provide a synergistic effect of electrochemical signal amplification and tetracycline recognition strategy. Under the optimal conditions, the proposed biosensor exhibited different electrochemical reactions for different concentrations of tetracycline, with a linear range of 1 nM-1000 μM and a detection limit of 0.16 nM. This work provides a new idea for rapid and sensitive detection of tetracycline by using a simple and economical tetracycline aptamer combined with Cu 2 O @ Au biosensor platform. [ABSTRACT FROM AUTHOR]