A highly sensitive EDTA-based senor for detection of disease biomarker and drug

Abstract

In this study, a fascinating photocatalytic property of EDTA under light irradiation was observed, much the same as that of natural horseradish peroxidase. The small EDTA molecules enable it easily attaches to amine terminal on antibody surface, an ELISA-like assay may be fabricated through combining with gold nanoparticles (AuNPs) in suspensions can exhibit various colors. The labeled EDTA on the proteins which may catalyze decomposition of hydrogen peroxide and in situ mediate the growth of hydrogen peroxide-induced formation of AuNPs, displaying various color nanoparticle dispersion as a read-out means. A straightforward plasmonic sensor was accordingly designed to enable naked-eye observation and quantitative determination of ultra-trace target analytes based on peroxidase-like EDTA. The highly sensitive assay was utilized to determine cancer antigen 15-3 (CA15-3, a breast cancer biomarker) and methamphetamine, and their limit of detection CA15-3 and methamphetamine are 7.5×10−15U/mL and 2.8×10−20mg/mL by naked eyes, respectively. Furthermore, practical applications for detection of CA15-3 and MA in human blood samples were also carried out. The results of detecting CA15-3 of breast cancer serum samples are close agreement with those given by hospital, implying this sensor with high accuracy. This assay has a great potential to be developed into a platform to quantitatively determine analytes as long as the specific antibodies against them were available. Its versatile features will broaden the applicability toward the ultrasensitive detection of target molecules in clinical diagnosis, environmental monitoring, and food quality control only using naked eyes.