Multiplexed Luminescence Oxygen Channeling Immunoassay Based on Dual‐Functional Barcodes with a Host–Guest Structure: A Facile and Robust Suspension Array Platform

Abstract

The development of a powerful immunoassay platform with capacities of both simplicity and high multiplexing is promising for disease diagnosis. To meet this urgent need, for the first time, a multiplexed luminescent oxygen channeling immunoassay (multi‐LOCI) platform by implementation of LOCI with suspension array technology is reported. As the microcarrier of the platform, a unique dual‐functional barcode with a host–guest structure composed of a quantum dot host bead (QDH) and LOCI acceptor beads (ABs) is designed, in which QDH provides function of high coding capacity while ABs facilitate the LOCI function. The analytes bridge QDH@ABs and LOCI donor beads (DBs) into a close proximity, forming a QDH@ABs–DBs “host–guest–satellite” superstructure that generates both barcode signal from QDH and LOCI signal induced by singlet oxygen channeling between ABs and DBs. Through imaging‐based decoding, different barcodes are automatically distinguished and colocalized with LOCI signals. Importantly, the assay achieves simultaneous detection of multiple analytes within one reaction, simply by following a “mix‐and‐measure” protocol without the need for tedious washing steps. Furthermore, the multi‐LOCI platform is validated for real sample measurements. With the advantages of robustness, simplicity, and high multiplexing, the platform holds great potential for the development of point‐of‐care diagnostics.

Functional Micro‐/Nanomaterials for Multiplexed Biodetection

“…Encapsulation of MNPs with coding signal labels, like QDs, into polymer microbeads allows these multifunctional microcarriers to realize ultrasensitive multiplexed biodetection. There are several different methods for codoping polymer microspheres with MNPs and QDs, including swelling, [256] LBL self-assembly, [108,257] sol-gel encapsulation, [186a] CCFF, [213] and membrane-assisted emulsification. [28b] By codoping three QDs with red, yellow and green emissions and Fe 3 O 4 NPs, researchers were able to generate three unique fluorescence-encoded nanoparticles with a magnetic separation efficiency higher than 99%.…”

“…The application of magnetic separation can effectively avoid the hook effect seen in obtained no-wash suspension array detection, resulting in a detection sensitivity that is five times higher than that of no-wash mode (Figure 19D). [108]…”

“…D) Reproduced with permission. [108] Copyright 2020, Wiley-VCH. interpretation and their peroxidase-like catalytic activity, generating a stronger blue color when tetramethylbenzidine (TMB) and H 2 O 2 exist (Figure 20B).…”

“…In this way, investigators can perform no-wash detection of twelve kinds of targets simultaneously. [108]…”

“…[283a] Copyright 2011, American Chemical Society. C) Reproduced with permission [108]. Copyright 2020, Wiley-VCH.…”