Label-free multiplexed detection based on core–shell photonic barcodes integrated RCA

Multiplexed, rapid, and accurate virus quantification is of great value in biomedical detection. Herein, we proposed a label-free multiplexed virus screening quantitative biosensor based on color core-shell hydrogel photonic crystal (PhC) barcode integrated rolling circle amplification (RCA). The composite hydrogel shell was formed by acrylic acid and polyethylene glycol diacrylate, and the core silica photonic crystal was used as a detector. In addition, by adjusting the internal periodic structure, the PhC microcarrier was able to perform various color barcodes for the detection of different targets. Based on these excellent properties of the nanocomposite barcode, the biosensor not only demonstrated the ability to rapidly and accurately detect SARS-COV-2-N, SARS-COV-2-S, and H1N1 simultaneously in one tube, but also converting the signal of target protein to nucleic acid signal based on DNA decorated antibody complex combine with the blocked primer and RCA strategy. As a result, the platform achieved highly sensitive multiplexed quantitative detection with a detection limit in the range of 0.30 pg/mL. In addition, the platform we developed was validated by clinical sample analysis with acceptable accuracy and high specificity, demonstrating the good potential applicability of the proposed detection method in clinical screening and diagnosis.