Interaction Study of Anti-E. coli Immobilization on 1DZnO at Nanoscale for Optical Biosensing Application

Abstract

Developing low-cost biosensing platforms for robust detection response and sensitivity at low concentrations is of great interest. This work reports synthesizing 1D ZnO nanostructured materials (1DZnO) with controllable properties utilizing a metal catalyst-assisted vapor phase growth technique (VLS). The obtained materials are functionalized with (3-aminopropyl) trimetoxysilane (APTMS) and immobilized with anti-Escherichia coli enteropathogenic (EPEC) antibodies. Characterization results show changes in the optical and structural properties of 1DZnO that are correlated with the biofunctionalization methodologies. Further, the biofunctionalization process is assessed on 1DZnO surface platforms to obtain acceptable antibody immobilization efficiencies (52%, 96%, and 100%) using a low-concentration antibody solution (30 µg ml−1). Special techniques such as focused ion beam micromachining and scanning tunneling electron microscopy are proposed to appreciate the semiconductor biofunctionalization layer around 1DZnO and explain the physics of the interaction process. It is found that morphology obtained from distinct synthesis methods, solvents, and functionalization agents can generate functional groups for biomolecule attachment. Remarkably, it is demonstrated that biofunctionalization on 1DZnO takes place all over a single nanostructure. This work presents a proof-of-concept focused on generating pathogen sensing platforms using 1DznO semiconducting materials, providing new insights into bio-analytes interaction with structures at the nanoscale.