Peptide-based biosensor for the detection of liver biomarker proteins

A general method for the facile development of new biosensors for detection of liver biomarker protein targets have constructed and characterized. The peptides as recognition element selected using M13 phage display. A quartz crystal microbalance (QCM) is used as a diagnosis tool during biosensor development, and electrochemical techniques (cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS)) are also used as the detection methods in the biosensor. A novel peptide capable of binding to alanine transaminase (ALT) was discovered by biopanning an M13 phage-displayed library. The selection procedure readily converged to a peptide (ALT5-8), with an amino acid sequence WHWRNPDFWYLK. The binding affinity of the peptide-containing phage particles was assessed by ELISA and the specific recognition of ALT was observed with a picomolar binding constant (Kapp= 8.14 pM). Peptides with the same sequence were chemically synthesized with a C-terminal cysteine and immobilized on a gold surface. These results demonstrate a simple platform for developing sensitive peptide-based biosensors for almost any desired protein targets.