(12f) Dual-Functional Zwitterionic Polymer Conjugates with An Adhesive Group Enable Sensitive and Specific Detection From Complex Media

The culprit underlying detection of cancer biomarkers directly from undiluted human blood serum using biosensors is the presence of non-specific protein adsorption. The overwhelming background noise generated as a result of biofouling leads to a significantly reduced limit of detection of these markers, which are already at low concentrations. Currently, there is a strong desire for developing new materials that not only contain ultra-low fouling and functionalizable properties but also allow for simple and convenient attachment onto a variety of materials. The end result will enable highly sensitive and specific detection of target analytes directly from complex media which can be applied to a variety of biosensor platforms. Here, zwitterionic carboxybetaine methacrylate (CBMA) polymer conjugates containing the adhesive biomimetic moiety, 3,4-dihydroxy-L-phenylalanine (DOPA), were grafted onto two substrates, gold and silica, which are common materials used in many sensing devices. Biofouling experiments performed using a Surface Plasmon Resonance (SPR) biosensor showed these coatings to be highly protein resistant to undiluted human blood serum and plasma. Subsequent unblocked antibody functionalized surfaces enabled the specific and sensitive detection of a model cancer biomarker directly from complex media. The ability of this novel ?graft to? method to resist protein adsorption and provide for highly sensitive picomolar detection limits using a Suspended Microchannel Resonator was then demonstrated. This work illustrates the potential impact of these novel polymer conjugates in the field of nano-scale biosensor development.