Immuno-optomagnetic point-of-care assay and method for detection of analyte using multi-functional optomagnetic quantum dot nanocrystals (mqds)

A method for detecting and quantifying of a target analyte in a test sample, comprising the steps of:

• i. providing a point-of-care (PoC) borofloat chip platform containing chambers functionalised with a first analyte specific reagent,
• ii. providing multi-colored CdSe/CdS/ZnS core-shell-shell quantum dot (QD) nanocrystals by mixing of pure single colored red and green QD nanocrystals, wherein QD nanocrystals comprise free —COOH functionality,
• iii. providing 50-100 nm sized optomagnetic quantum dot (MQD) nanocrystals, wherein 3-10 nm sized CdSe/CdS/ZnS multi-colored QD nanocrystals are coated with 7-12 nm sized magnetic nanoparticles,
• iv. providing a plurality of optomagnetic MQD nanocrystals functionalised with a second analyte specific reagent, capable of binding to analyte followed by the first analyte specific reagent,
• v. contacting the plurality of optomagnetic MQD nanocrystals with the test sample and forming MQD nanocrystals-second analyte specific reagent-target analyte complex,
• vi. separating the MQD nanocrystals-second analyte specific reagent-target analyte complex from test sample using an external magnet,
• vii. loading the MQD nanocrystals-second analyte specific reagent-target analyte complex in step vi onto the PoC borofloat chip platform in step i and forming a sandwich complex between the PoC borofloat chip platform and the MQD nanocrystals-second analyte specific reagent-target analyte complex,
• viii. exposing a PoC borofloat chip to UV light and detecting and/or quantifying a target analyte fluorescence signal.