Multiplexed detection of tumor biomarkers utilizing immunohybridization Chain reaction integrated photonic barcodes

Abstract Multiplexed detection of cancer markers is of great value in clinical diagnosis. Herein, we present a new immunoassay method for simultaneous quantification of multiple tumor biomarkers. Our approach integrates photonic crystals (PhC) barcodes with DNA hybridization chain reaction (HCR) to amplify signal. Target biomarkers are captured by primary antibodies which are immobilized onto the PhC barcodes, forming sandwich immunocomplex with the assistance of second antibodies that are conjugated with DNA initiator. Subsequently, a chain reaction of hybridization events is propagated in attendance of a pair of complementary FAM-decorated H1 and H2 hairpin probes. As a result, the PhC barcodes exhibit multiplex encoding ability for different markers. By utilizing PhC barcodes with HCR for immunoassay, low-abundance cancer biomarkers (CEA, AFP and PSA) can be screened with high detection sensitivity and specificity. Our results showed a wide range from 0.001 to 1000 ng/mL; and the detection limit as low as 0.50 pg/mL. Our approach was also evaluated for analyzing human serum sample with considerable accuracy, which implies its potential as a new platform for simultaneous multiplex immunoassay.