M13 phage as network frame for the quantification of Pb2+ based on the Pb2+-induced in-situ growth of gold nanoparticles.

Abstract

Routine detection of Pb2+ is of great importance to environmental monitoring because of its deleterious effects on human health and environment. In this work, an easy-to-operate method for the one-step detection of Pb2+ was developed based on the phage-Pb2+ interactions and their influence on the surface plasmon resonance (SPR) absorption band of AuNPs. AuNPs grow in-situ on the surface of M13 phages and the resulting phage-AuNP networks were directly used for lead sensing. The addition of Pb2+ facilitates further growth of the parent AuNPs and results in a blue shift of the SPR absorption peak. By integrating AuNPs preparation and sensing procedure into one step, a simplified Pb2+ detection approach was developed with improved sensitivity and shortened analysis time. By quantifying A528 with UV-vis spectrometer, a linear range of 0.5-5.0\u202fμmol\u202fL-1 together with a limit of detection of 45\u202fnmol\u202fL-1 was obtained. The one-step approach avoided complicated AuNPs preparation and functionalization process, and got rid of the unstable problems of AuNPs for long-term preservation, offering simple and cost-effective Pb2+ detection method for resource-poor settings.