Specific recognition of ribavirin in animal-derived foods by high performance liquid chromatography combined with magnetic solid-phase extraction based on highly selective Zr-Fe3 O4.

For the first time, a magnetic solid-phase extraction with high-performance liquid chromatography detection method using Zr functionalized Fe3 O4 magnetic material to enrich ribavirin was successfully established. Zr components that modified in Fe3 O4 nanoparticles via a simple one-step hydrothermal method was selected in this work to specifically capture ribavirin by the strong chemical bonding between Zr components of Zr functionalized Fe3 O4 magnetic material and cis-hydroxyl of ribavirin, which was confirmed by pseudo-second-order kinetic model. And Fe3 O4 components were selected in this work to achieve simple operation. Under the optimal experimental conditions, proposed magnetic solid-phase extraction with high-performance liquid chromatography detection method along with Zr functionalized Fe3 O4 magnetic material offered a wide range linearity at 10-200 µg/L with correlation coefficient of 0.9978 with low detection limit of 2.68 µg/L for ribavirin. The relative standard deviations obtained from nine parallel extractions of 100 µg/L ribavirin were 4.41% and revealed good repeatability. This established method was successfully applied to detect real samples including chicken liver, egg, and shrimp with satisfactory recoveries of 74.13-92.9%.

In-situ graft-crosslinked gold nanoparticles with high-density surface defects and coated with a polytaurine membrane for the voltammetric determination of dopamine.

Well-dispersed and graft-crosslinked gold nanoparticles (AuNPs) were synthesized by the reduction of tetrachloroaurate with hydrazine at room temperature. The AuNPs possess a high density of surface defects which is due to grafting of n-octanoic acid to polyvinylpyrrolidone. The physical and chemical properties of the resulting AuNPs were characterized by UV-vis, XRD, TEM/HRTEM, SAED, and XPS, respectively. The modified AuNPs were placed on a glassy carbon electrode (GCE) in an electropolymerized taurine layer to obtain a sensitive, selective, stable and rapid electrochemical dopamine sensor. The peak current, typically measured at 0.17 V (vs. SCE), increases linearly in the 1.0 to 120 µM dopamine concentration range, and the limit of detection (at S/N = 3) is 0.16 µM with a sensitivity of 2.94 µA·µM-1·cm-2. The sensor was successfully applied to the determination of dopamine in injections and spiked serum samples. The recoveries from spiked serum samples range from 97.5 to 102.4%, with RSDs ranging between 2.8 and 3.4%. Graphical abstract Schematic representation of a glassy carbon electrode modified with in-situ graft-crosslinked gold nanoparticles combined with an electropolymerized polytaurine membrane. The sensor exhibits excellent features towards dopamine determination.

Construction of a piezoelectric immunosensor for ultra-sensitive and highly selective detection of ribavirin in animal-derived foods.

In this work, a suppressive piezoelectric immunosensor based on the ultra-sensitive quartz crystal microbalance and highly specific immunosorbent assay was constructed for the detection of ribavirin for the first time. The carboxyl group was modified on the surface of the gold electrode by electropolymerization, and then the carboxyl group was combined with the amino-modified antigen, and then the corresponding antibody was able to bind to it according to the principle of immune recognition, which interlocked to cause the frequency change of the piezoelectric sensor. The preparation conditions of the sensor and the antibody concentration were optimized, and the performance of the sensor was evaluated. Under the optimal conditions, a wide linear range of 1-750 µg L-1, a low detection limit (IC15) of 2.64 µg L-1, and a good sensitivity (IC50) of 31.49 µg L-1 were obtained. The sensor was used for the detection of ribavirin in chicken and milk samples, and the recovery rate ranged from 88.01 to 94.42%, which shows satisfactory consistency with the detection results of high performance liquid chromatography. It was suggested that the proposed piezoelectric immunosensor has good sensitivity and selectivity for ribavirin, and can be applied to the detection of actual food samples.