Development of a new dual electrochemical immunosensor for a rapid and sensitive detection of enrofloxacin in meat samples

A novel dual electrochemical immunosensor was fabricated for the rapid and sensitive detection of enrofloxacin (EF) antibiotic in meat. Anti-quinolone antibody was immobilized onto screen-printed dual carbon electrodes via carbodiimide coupling. A new electrochemical probe was synthesized by conjugating difloxacin and aminoferrocene, whose oxidation was measured at + 0.2 V vs. Ag/AgCl by differential pulse voltammetry. The detection principle was based on the competitive binding of this conjugate and free EF on immobilized antibodies. The proposed immunosensor allowed detection of EF at concentrations ranging from 0.005 µg.mL^-1 to 0.01 µg.mL^-1 with a detection limit of 0.003 µg.mL^-1. The immunosensor was stable for at least 1 month at 4 °C and displayed a good specificity for other fluoroquinolones. The new dual electrode design offered an improved accuracy as one electrode was used as negative control. The efficiency of the sensor and the adequacy of the extraction process were finally validated by detecting EF in different meat samples.

Bismuth telluride decorated on graphitic carbon nitrides based binary nanosheets: Its application in electrochemical determination of salbutamol (feed additive) in meat samples

The design and fabrication of effective electrochemical sensor for ultrasensitive detection of feed additive and multidrug are highly significant in food analysis. In this work, we explored to develop the possibility for rapid detection of feed additive drug using bismuth telluride (Bi₂Te₃) decorated graphitic carbon nitrides (GCN) nanostructures as a modified electrode for electrochemical sensing. Herein, the modified electrode was focused on the development of electrocatalytic performances for the determination of salbutamol in food products. The electrochemical sensors are developed by bismuth telluride sheets interconnected with graphitic carbon nitrides sheets (Bi₂Te₃/GCN) on to a screen-printed carbon electrode. The binary nanosheets of Bi₂Te₃/GCN exhibited an enhanced electrocatalytic ability towards salbutamol detection owing to their selective adsorption, by the combination of electrostatic interaction of binary nanosheets and the formation of charge assisted interactions between salbutamol and Bi₂Te₃/GCN surfaces. A nanomolar limit of detection (1.36 nM) was calculated in 0.05 M phosphate buffer (PB) supporting electrolyte (pH 7.0) using differential pulse voltammetry. The linear dynamic ranges with respect to salbutamol concentration were 0.01-892.5 μM, and the sensitivity of the sensor was 36.277 μA μM^-1 cm^-2. The sensor stability and reproducibility performances were observed. However, the obtained results are highly satisfactory which suggest the application of binary nanosheets in real-time food analysis.

Physiological effects of transport duration on stress biomarkers and meat quality of medium-growing Yellow broiler chickens

Pre-slaughter transport exerts negative effects on broilers' welfare, meat yield, and meat quality, but little is known about the effect of transport on medium-growing broiler chickens. This study aimed at evaluating the effects of different durations of transport (0, 0.5, 1, 2, and 3h) on stress biomarkers and meat quality of medium-growing Yellow-feathered broiler chickens. One hundred and eighty Chinese Yellow-feathered broilers aged 75days (marketing age), of 2.02kg average BW, were allotted into five groups; each group contained six replicates (six birds/replicate (crate)). Each crate with dimensions 74×55×27cm (length × width × height) was loaded with six birds, that is, 30kg live BW/m² crate. The tested transport durations increased BW loss (linear, P<0.01), plasma concentrations of ACTH (linear, P<0.10), cortisol and corticosterone (quadratic, P<0.05), and activity of glutathione peroxidase (linear, P<0.05), whereas plasma glucose was not affected. In breast muscle, contents of glycogen, lactic acid, malondialdehyde, and reduced glutathione were not affected (P>0.05), but total antioxidant capacity decreased (linear, P<0.01). The drip loss of breast muscle increased (linear, P<0.01), whereas shear force, pH at 24h postmortem, and breast meat color lightness (L*), redness (a*), and yellowness (b*) scores were not affected. In conclusion, the tested transport durations (from 0.5 to 3h) increased BW loss and some plasma stress biomarkers in 75-day-old Yellow-feathered broiler chickens, but the effect on meat quality attributes was minor.