Abstract
Digital multiplexed homogeneous immunoassay is supposed to have the advantages of high sensitivity, high analytical throughput, small sampling errors, and low consumption. We present a spectral imaging-based multiplex, homogenous immunoassay by counting sandwich-structured immunocomplexes in the form of quantum dot (QD) aggregates. As a proof of concept, the method was utilized to detect two tumor biomarkers: carcino-embryonic antigen (CEA) and α-fetoprotein (AFP). The immunocomplex induced by CEA contained QD 655 and QD 585 and were recognized by the spectral pattern of dual-color QD aggregates under a transmission-grating-based spectral imaging microscope. Immunocomplexes induced by AFP were labeled with the QD 585 aggregate and were identified by the spectral blue-shift pattern of same-color QD aggregates. Limits of detection for AFP and CEA were calculated to be 0.02 and 0.10 pM at a signal-to-noise ratio of 3, respectively. Further successful quantification of the model proteins in human plasma demonstrated the accuracy and reliability of our approach.
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.
