Detection of copper ions and glutathione based on off-on fluorescent gra-phene quantum dots / 中国药科大学学报

We developed a rapid method to detect Cu2+and glutathione(GSH)based on the fluorescence quenching-recovery properties of graphene quantum dots(GQDs),which were synthesized by the gentle oxidation of graphite powder.The results revealed that the fluorescence intensity of GQDs versus concentration of Cu2+and GSH had good linearity, with the detection limits of 0.01 and 0.1 mmol/L, respectively.The fluorescence quenching was linearly proportional to the concentrations of Cu2+ranging from 1.0 to 10.0 mmol/L;the fluores-cence intensity was linearly enhanced with the concentrations of GSH ranging from 0.1 to 1.0 mmol/L.In addi-tion,the method was successfully applied to the determination of real samples with recoveries falling between 93％-101％ and 96％-107％,respectively.This method is simple,accurate and precise.There was no interference with other familiar co-existing metal ions and potential materials.

Detection of prostate specific antigen-based on dual signal amplified electrochemical immunoassay / 中国药科大学学报

@#A sandwiched electrochemical immunoassay based on the AuNPs@GSH-CdTe as a signal label, which formed by GSH-CdTe QDs and AuNPs, with dual signal amplified by reduced graphene oxide and AuNPs was proposed for the sensitive detection of prostate specific antigen(PSA). Through a sandwich immunoreaction, the target PSA and AuNPs@GSH-CdTe labeled Ab1 were captured to rGO/AuNPs-Ab2 surface. After the HNO3-dissolution step, square wave stripping voltammetry(SWSV)analysis of the captured CdTe QDs was used to quantify the concentration of PSA. In this system, AuNPs possessedlarge specific surface and good biocompatibility, which could effectively expand the amount of antigen and GSH-CdTe QDs loading and signals amplifying, while rGO played a synergistic amplification role due to its large specific surface. The proposed method showed good linearity ranging from 0. 5 to 200 ng/mL with the detection limits of 5. 0 pg/mL. It also showed excellent selectivity, good reproducibility, satisfactory stability. In addition, the method was successfully applied to the determination of real samples. The result was satisfactory and the recovery could fall in 98. 20%- 106. 2%, which represented a novel approach for versatile detection of tumor markers.