Sensitive determination of tobramycin using homocystine capped gold nanoclusters as probe by second-order scattering

Second-order scattering sensor based on the Zn0.97La0.03O compound for selective and stable detection of glycated albumin

Here, we presented a second-order scattering sensor based on the Zn0.97La0.03O compound (LaZnO) for selective and stable detection of glycated albumin (GA, glycemic long-term biomarker). The LaZnO sample was obtained through the co-precipitation method and then characterized using microscopic and spectroscopic techniques. Furthermore, the selectivity, molecular interference, temporal stability, and pH effects of the LaZnO SOS signal in the absence and presence of GA were investigated. The results indicate the stability of the SOS signal over more than 60 days. Assays conducted within the pH range of 5 to 8 indicate that the detection of GA remains unaffected under the given conditions. Selectivity studies show that the SOS signal of LaZnO is reduced only upon contact with GA, while interference studies show that detection is not affected by other chemical species. Additionally, the calibration curve test showed high sensitivity of the material, with a detection limit of 0.55 µg/ml. All the results suggest that LaZnO can deliver efficiency, selectivity, accuracy, and fast response as a GA biosensor, emphasizing LaZnO's usefulness in detecting protein biomarkers.

Sophorajaponica L. flower mediated carbon dots with nitrogen and sulfur co-doped as a sensitive fluorescent probe for amoxicillin detection

This article first reported the green synthesis of N, S co-doped fluorescent carbon dots (N, S-CDs-Sop) and sought to establish the fluorescence detection system for amoxicillin (AMX). By using Sophorajaponica L. flower as the green precursor and dl-homocystine as the co-dopant, N, S-CDs-Sop were successfully prepared via a one-pot hydrothermal method, exhibiting good water solubility and excellent photoluminescence. It was revealed that the surface of N, S-CDs-Sop was abundant in amino, hydroxyl and carboxyl groups after being characterized by a variety of techniques. When Fe³⁺ was added, Fe³⁺ could be complexed with N, S-CDs-Sop to from N, S-CDs-Sop-Fe³⁺ chelation leading to a significant static quenching of fluorescence. However, when N, S-CDs-Sop, Fe³⁺ and AMX coexisted, AMX would coordinate with Fe³⁺ and form the strong chelate due to the favorable chemical structure, resulting in the rapid fluorescence recovery. Such a fast, simple and sensitive fluorescence "off-on" strategy with a low LOD and a relatively wide range was successfully applied to the detection of AMX, which is closely correlated with human health.