Disposable and cost-effective label-free electrochemical immunosensor for prolactin based on bismuth sulfide nanorods with polypyrrole.

Prolactin (PRL) is produced by the pituitary gland and plays a vital role in the production of milk after a baby is born. PRL levels are normally elevated in pregnant and nursing women, and high levels of PRL in the human body cause hyperprolactinemia, infertility, galactorrhea, infrequent or irregular periods, amenorrhea, breast pain, and loss of libido. Accordingly, herein, a novel label-free immunosensor using a bismuth sulfide/polypyrrole (Bi2S3/PPy)-modified screen-printed electrode (SPE) for the fast and facile detection of the peptide hormone PRL. Bi2S3 nanorods were synthesized via a facile hydrothermal technique, and PPy was prepared by chemical polymerization method. Subsequently, the Bi2S3/PPy/ SPE was modified with 3-mercaptopropionic acid (MPA) and EDC/NHS. Owing to the cross-linking effect of EDC/NHS, antibody-PRL (anti-PRL) was firmly stabilized on the modified SPE surface. These layer-by-layer modifications enhanced the conducting properties, anti-PRL loading capacity, and sensitivity of the developed immunosensor. Under optimized conditions, the PRL immunosensor demonstrated a broad linear range of approximately 1-250 ng/mL, a low detection limit of approximately 0.130 ng/mL (3 × SD/b), good specificity, reproducibility, and stability. PRL was successfully evaluated in human and mouse serum samples, and the corresponding outcomes were compared with those of the electrochemical and ELISA methods.

Cost-effective single-step synthesis of flower-like cerium-ruthenium-sulfide for the determination of antipsychotic drug trifluoperazine in human urine samples.

Nanostructured binary metal sulfides are considered as a promising electrode material because of their excellent electron transfer and good sensing behavior rather than metal oxides. As a result, the binary metal sulfides were applied in energy and electrochemical sensor applications. Herein, we propose the electrochemical sensor method based on flower-like cerium-ruthenium sulfide nanostructure (Ce-Ru-S NS) for the electrochemical sensing of trifluoperazine (TFPZ). The Ce-Ru-S NS prepared using the cost-effective one-pot hydrothermal synthesis technique. Then, the resultant materials were characterized through suitable spectrophotometric techniques and the electrocatalytic properties of the fabricated sensor were investigated by EIS, CV, and amperometric (i-t) techniques. The Ce-Ru-S material has good electrocatalytic activity towards the electrochemical oxidation of TFPZ. Significantly, the fabricated sensor demonstrates the distinct amperometric response with the lowest limit of detection (LOD) of 0.322 nM (S/N = 3), high sensitivity 2.682 µA µM-1 cm-2 and lowest oxidation potential of +0.64 V (Ag/AgCl). Furthermore, the Ce-Ru-S NS displays excellent selectivity, good reproducibility, and long-term stability. The practicability of the TFPZ sensor tested in a human urine sample.