Preparation of analyte-sensitive polymeric supports for biochemical sensors

The preparation and use of multiple polymers attached to a surface plasmon resonance (SPR) sensor for optimization of signal enhancement and minimization of fouling during sensing of biological species has been achieved. These polymers are advantageous compared to the current practice of carboxymethylated-dextran (CM-dextran). The polymers offer a wide range of functionalities and different molecular weights. Using these polymers, the SPR sensors can be fabricated as fast or faster than the CM-dextran sensor. In this study, we investigated the use of nine polymers for SPR biosensors. Polysaccharides, including CM-dextran, CM-hyaluronic acid, hyaluronic acid, and alginic acid, were investigated. Humic acid, polylactic acid, polyacrylic acid, orthopyridyldisulfide-polyethyleneglycol-N-hydroxysuccinimide (OPSS-PEG-NHS) and a synthesized polymer; polymethacrylic-acid-co-vinyl-acetate (PMAVA), were also used. The polymers were chemically attached to a thiol monolayer on the SPR biosensor using carbodiimide chemistry. The polymers were functionalized for binding of anti-myoglobin (anti-MG). The sensor performance was measured using myoglobin (MG) at 25 ng ml⁻¹, a biologically relevant level for myocardial infarction detection. Most polymers offered similar performance to CM-dextran for MG detection in HEPES buffer saline pH 7.4 (HBS). In preliminary studies in bovine serum, each of the candidate polymers demonstrated better performance than CM-dextran.