Low Fouling Protein Detection in Complex Biological Media Supported by a Designed Multifunctional Peptide

The construction of sensitive and selective biosensors capable of detecting specific targets in complex biological samples remains a challenge highly relevant to a range of sensor/diagnostic applications. Herein, we have utilized a multifunctional peptide to present an interface that supports the very specific recruitment of targets from serum. The novel peptide sequence designed contains an anchoring domain (CPPPP-), an antifouling domain (-NQNQNQNQDHWRGWVA), and a human immunoglobulin G (IgG) recognition domain (-HWRGWVA), and the whole peptide was designed to be antifouling. These were integrated into polyaniline nanowire arrays in supporting the quantification of IgG (with a limit of detection of 0.26 ng mL^-1) in neat serum and real clinical samples. The strategy of utilizing multisegment peptide films to underpin highly selective target recruitment is, of course, readily extended to a broad range of targets for which an affinity sequence can be generated.