Abstract
An immunoassay is described for either colorimetric and fluorometric determination of the cancer biomarker α-fetoprotein (AFP). It is making use of ZnS nanospheres modified with CdTe quantum dots (QDs). These display strong fluorescence due to the enrichment of the QDs onto the porous ZnS nanospheres. In this assay, the release of millions of zinc(II) ions can be triggered to form a purple complex (with an absorption maximum at 571nm) on addition of the reagent 2-(5-nitro-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino) phenol. This results in a sensitive colorimetric immunoassay which can also be used as a visual test. It represents an enzyme-free alternative to the commonly used ELISAs. It also can be evaluated by fluorometry (with excitation/emission maxima at 400/645nm). The detection limits are 10pg·mL-1 for fluorometry and 7pg·mL-1 for colorimetry. This sensitivity is better by one order of magnitude than that of the commercial ELISA. The dual detection feature provides good complementarity and reduces the risk of false-positive or false-negative results. Graphical abstract Schematic presentation of colorimetric and fluorescent dual-channel detection for α-fetoprotein. ZnS-CdTe hierarchical porous nanospheres are usedas labels for signal amplification.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
