Molybdenum disulfide-integrated photonic barcodes for tumor markers screening

As a new class of two-dimensional (2D) materials, molybdenum disulfide (MoS 2 ) has huge potential in biomedical area; while its applications in multiplex bioassays are still a challenge. Here, we present novel MoS 2 -integrated silica colloidal crystal barcode (SCCB) for multiplex microRNA (miRNA) screening. MoS 2 was adsorbed on SCCBs by electrostatic interaction , and quantum dots (QDs) decorated hairpin probes were coupled on MoS 2 by covalent linkage. As the MoS 2 could quench the QDs of the hairpin probes, they together formed a molecular beacon (MB) structure before the detection. When used in assays, target miRNA could form a double strand with the probe and made QDs keep away from MoS 2 sheets to recovery their fluorescence. Because the released QDs were positively correlated with the concentration of the hybridized nucleic acid , the target miRNAs could be quantified by measuring the fluorescence signal of the QDs on the SCCBs. In addition, by utilizing different MoS 2 -integrated structural color encoded SCCBs, multiplexed miRNA quantification could also be realized. Based on this strategy, we have demonstrated that several pancreatic cancer-related miRNAs could be selectivity and sensitivity detected with a detection limit of 4.2 ± 0.3 nM. These features make the MoS 2 -integrated SCCB ideal for many potential applications.