Quartz crystal microbalance (QCM) biosensors for recombinant human interferon-beta (rhIFN-beta) were constructed by utilizing antisense peptides adhering to the QCM gold surfaces. Two antisense peptides, both corresponding to the N-terminal fragment 1-14 of rhIFN-beta, were used in this study. Antisense peptide AS-1 was the original antisense peptide and AS-2 was the modified antisense peptide based on the antisense peptide degeneracy. Both antisense peptides were immobilized on the gold electrodes of piezoelectric crystals, respectively, via a self-assembling monolayer of 1,2-ethanedithiol. The binding affinity between rhIFN-beta and each immobilized antisense peptide in solution was evaluated using a quartz crystal microbalance-flow injection analysis (QCM-FIA) system. The dissociation constant of rhIFN-beta on the antisense peptide AS-1 and AS-2 biosensor was (1.89+/-0.101) x 10(-4) and (1.22+/-0.0479) x 10(-5) mol L(-1), respectively. The results suggested that AS-2 had a higher binding affinity to rhIFN-beta than AS-1. The detection for rhIFN-beta using each biosensor was precise and reproducible. The linear response ranges of rhIFN-beta binding to both biosensors were same with a concentration range of 0.12-0.96 mg mL(-1). The results demonstrated the successful construction of highly selective QCM biosensors using antisense peptide approach, and also confirmed the feasibility of increasing antisense peptide binding affinity by appropriate sequence modification.
Biosensing Techniques Chromatography, High Pressure Liquid