Hybrid Surface Platform for the Simultaneous Detection of Proteins and DNAs Using a Surface Plasmon Resonance Imaging Sensor

摘要

In this work,we present a novel surface and assay for the simultaneous detection of DNA and protein analytes on a surface plasmon resonance(SPR)imaging sensor.A mixed DNA/oligo(ethylene glycol)(OEG)self-assembled monolayer(SAM)is created using a microarrayer.Thiol-modified single-stranded DNA sequences are spotted onto a gold-coated glass substrate.Backfilling with an OEG-modified alkanethiol creates a protein-resistant surface background.Antibodies conjugated to complementary single-stranded DNA sequences are immobilized on the surface through DNA hybridization.By converting only part of the DNA array into a protein array,simultaneous detections of DNA and protein analytes are possible.A model system of two cDNA sequences and two human pregnancy hormones are used to demonstrate the assay.No cross-reactivity was observed between DNA or protein analytes and nontargeted immobilized cDNA sequence or antibodies.A response from a detection of a single analyte in a mixture of protein and DNA analytes corresponds well with that of a single-analyte solution.