近期，我院教师卞婷的“Signal amplification strategy for biomarkers: Structural origins of epitaxial-growth twinned nanocrystals and D–π–A type polymers”研究成果在《Biosensors and Bioelectronics》上合作发表。
The combination of nanoparticles and biomarkers yields functional nanostructured biointerfaces, which is playing a notable role in biotechnology development. Due to the exposed multiple twin boundaries and strain-induced electronic effects, Au-Pt core-shell star-shaped decahedra as the efficient signal transduction label is first employed to construct an electrochemical immunosensor for nonenzymatic hydrogen peroxide detection. Donor–π-linker–Acceptor (D–π–A) linking fashion generates a dipolar push-pull system and assures superior intramolecular charge transfer. It is considered as a suitable π-conjugated backbone for conducting polymers on biointerface applications. Under a D–π–A architecture which imidazole as the π-bridge and amino phenyl/phenyl groups as peripheral electron-donating/withdrawing functional groups, 4-(2,4,5-triphenyl-1H-imidazol-1-yl) aniline (TPIDA) is designed and synthesized for good biocompatibility and high conductivity. In this proposal, we attempt to integrate the above-motioned two features from nanobiotechnology and organic bioelectronics. Then, a novel nonenzymatic sandwich-type immunosensor is performed by Au-Pt core-shell with surface-engineered twinning as a label and π-conjugated D–π–A polymers as the signal amplification platform. Human IgG (HIgG) as the model target protein can be detected with a wide linear range from 0.1 pg mL-1 to 100 ng mL-1. The detection limit is down to 0.06 pg mL-1 (S/N = 3). Moreover, as a practical application, the prepared biosensor is used to monitor HIgG level in human serum with desirable results obtained.
Scheme 1. Work flow diagram for biosensor development.
Fig. 1. (a) CVs of the Au-Pt nanocrystal-Ab2 modified electrode in N2-saturated 0.1 M PBS (pH = 7.4) without (curve A) and with (curve B) 5 mM H2O2. Scan rate: 0.10 V s−1. (b) The EIS of poly(TPIDA)/GCE.