Dual ß-cyclodextrin functionalized Au@SiC nanohybrids for the electrochemical determination of tadalafil in the presence of acetonitrile.

This finding described the electrochemical detection of tadalafil based on CM-ß-cyclodextrin and SH-ß-cyclodextrin functionalized Au@SiC nanohybrids film. The tadalafil electrochemical signal could be dramatically amplified by introducing 40% of acetonitrile in buffer medium and further enhanced by the host-guest molecular recognition capacity of ß-cyclodextrin. Uniform and monodispersed ~5.0 nm Au NPs were anchored on the SiC-NH2 surface via a chemical reduction process by using polyethylene glycol and sodium citrate as dispersant and stabilizing agent. CM-ß-CD was covalently bound on Au@SiC by combining the amine group of SiC-NH2 with the carboxyl group of CM-ß-CD with the aid of EDC/NHS coupling agent. SH-ß-CD could tightly attach to the surface of Au@SiC by the strong coordinating capability between Au and thiol. Differential pulse voltammetry was successfully used to quantify tadalafil within the concentration range of 0.01-100 µM under optimal conditions with a detection limit (S/N = 3) of 2.5 nM. In addition, the ß-CD-Au@SiC nanohybrid electrochemical sensor showed high selectivity to two other erectile dysfunction drugs sildenafil and vardenafil. The proposed electrochemical sensing platform was successfully used to determine tadalafil in raw materials, herbal sexual health products, and spiked human serum samples.

A highly sensitive electrochemical sensor for simultaneous determination of hydroquinone and bisphenol A based on the ultrafine Pd nanoparticle@TiO2 functionalized SiC.

A titanium dioxide-silicon carbide nanohybrid (TiO2-SiC) with enhanced electrochemical performance was successfully prepared through a facile generic in situ growth strategy. Monodispersed ultrafine palladium nanoparticles (Pd NPs) with a uniform size of ∼2.3 nm were successfully obtained on the TiO2-SiC surface via a chemical reduction method. The Pd-loaded TiO2-SiC nanohybrid (Pd@TiO2-SiC) was characterized by transmission electron microscopy and X-ray diffractometry. A method for the simultaneous electrochemical determination of hydroquinone (HQ) and bisphenol A (BPA) using a Pd@TiO2-SiC nanocomposite-modified glassy carbon electrode was established. Utilizing the favorable properties of Pd NPs, the Pd@TiO2-SiC nanohybrid-modified glassy carbon electrode exhibited electrochemical performance superior to those of TiO2-SiC and SiC. Differential pulse voltammetry was successfully used to simultaneously quantify HQ and BPA within the concentration range of 0.01-200 µM under optimal conditions. The detection limits (S/N=3) of the Pd@TiO2-SiC nanohybrid electrode for HQ and BPA were 5.5 and 4.3 nM, respectively. The selectivity of the electrochemical sensor was improved by introducing 10% ethanol to the buffer medium. The practical application of the modified electrode was demonstrated by the simultaneous detection of HQ and BPA in tap water and wastewater samples. The simple and straightforward strategy presented in this paper are important for the facile fabrication of ultrafine metal NPs@metal oxide-SiC hybrids with high electrochemical performance and catalytic activity.