posted on 2022-01-05, 13:36authored byZuying Feng, Qingsheng Guo, Yao Wang, Yunfei Ge, Zhiying Zhang, Yan Wu, Qilong Li, Hajar Masoomi, Hongchen Gu, Hong Xu
The multiplexed luminescence
oxygen channeling immunoassay (multi-LOCI)
platform we developed recently that combines conventional LOCI and
suspension array technology is capable of realizing facile “mix-and-measure”
multiplexed assays without tedious washing steps. However, previous
work lacks comprehensive studies of the structure–performance
relationship of the host–guest-structured barcode, which may
obstruct the evolution and further translation of this exciting new
technology to practical applications. Accordingly, this work revealed
that polyelectrolyte interlayers played a crucial role in tuning the
packing density of guest acceptor beads (ABs). More interestingly,
we noticed that “sparse” barcodes (barcodes with low
ABs packing density) exhibited comparable assay performance with “compact”
ones (barcodes with high ABs packing density). The high robustness
of barcodes allows for multi-LOCI to be a more universal and flexible
assay platform. Furthermore, through optimization of the assay system
including the laser power, as well as the concentrations of donor
beads and biotinylated detection antibodies, the multi-LOCI platform
showed a significant improvement in sensitivity compared with our
previous work, with the limit of detection decreasing to as low as
ca. 1 pg/mL. Impressively, multi-LOCI that enabled simultaneous detection
of multiple analytes exhibited comparable sensitivity with the classical
single-plexed LOCI, due to the ingenious structural design of the
multi-LOCI barcode and the unique “on-barcode” assay
format.