Photoelectrochemical quenching-recovery biosensor based on NSCQDs/Fe2O3@Bi2S3 for the detection of trypsin.

BACKGROUND: The content of trypsin will change when pancreatic diseases occur, therefore developing a high-performance method for trypsin detection is of great significance for guiding patients on medication plans and improving their prognosis. Photoelectrochemical (PEC) analysis techniques have emerged as a solution to apply for bioassays. RESULTS: Herein, the Fe2O3@Bi2S3 and Nitrogen and sulfur co-doped carbon quantum dots (NSCQDs) were successfully synthesized by a hydrothermal method. Subsequently, NSCQDs/Fe2O3@Bi2S3 with a photocurrent amplification effect covered on fluorine-doped tin oxide (FTO) electrode as the substrate material and apoferritin (APO) as a bio-recognition element to quench the photocurrent of the substrate material which can be excited with light. Due to the decomposition specifically between APO and trypsin, the photocurrent response increased. The linear range for trypsin detection showed satisfied results from 2 to 1000 ng mL-1 under optimal conditions, with a detection limit of 0.42 ng mL-1 and a recovery rate of 97.41 %-103.02 %, enabling efficient quantitative analysis of trypsin. SIGNIFICANCE: In this experiment, a PEC biosensor with simple operation, low detection limit, excellent selectivity and strong stability was successfully prepared, enabling quantitative analysis of trypsin in human serum samples through the quenching-recovery mechanism. It holds great significance for diagnosis and serves as a practical method for the detection of trypsin in the future.

The systematic characterization of multiple components and metabolic profiling of bioactive constituents in Yaobitong capsule by UHPLC/Q-TOF-MS/MS.

Yaobitong capsule is a valuable traditional Chinese medicine prescription (TCMP), which can effectively treat lumbar disc herniation clinically. However, the effective substances in Yaobitong capsule are still unclear due to a lack of metabolic studies. This poses a huge obstacle preventing the clinical safety assessment and quality control of Yaobitong capsule. In order to explore the metabolic landscape of the multiple components of Yaobitong capsule, this paper proposed a rapid and high-throughput UHPLC/Q-TOF-MS/MS method for carrying out a systematic study, including analyzing the chemical ingredients in vitro and studying the metabolic processes in rat urine, feces, and bile after the oral administration of Yaobitong capsule. A total of 90 Yaobitong-capsule-related chemical components were characterized or tentatively identified in extract solution based on the retention behaviors, measured mass values, and fragmentation patterns. Furthermore, 49 related metabolites were detected in urine, feces, and bile samples. All metabolites were also identified with the help of the Sciex OS tool from these biological samples. The results revealed that triterpenoid saponins, alkaloids, monoterpene glycosides, and phthalides were the main chemical components of Yaobitong capsule. In addition, glucuronidation, hydroxylation, sulfation, and N-acetylcysteine conjugation were the main metabolic reactions in rats after the oral administration of Yaobitong capsule. The results indicated that the established method for multicomponent metabolism identification was appropriate, and the metabolic profiling of Yaobitong capsule provides abundant material for a wide range of further research; this is of significance for carrying out studies of pharmacodynamic mechanisms.