Capillary microfluidics-assembled virus-like particle bio-nano-receptor interfaces for label-free biosensing.

In this paper, a capillary microfluidics-integrated sensor system is developed for rapid assembly of bionanoreceptor interfaces on-chip and label-free biosensing. Genetically engineered Tobacco mosaic virus (TMV) virus-like particle (VLP), displaying thousands copies of identical receptor peptides FLAG-tags, are utilized as nanoceptors for antibody sensing. Controlled and accelerated assembly of VLP receptor layer on impedance sensor has been achieved using capillary effect and surface evaporation from an open-channel capillary microfluidic system. VLPs create a dense and localized receptor monolayer on the impedance sensor using only 5 μL of VLP sample (0.2 mg/mL) in only 6 minutes at room temperature. The VLP-functionalized impedance sensor is capable of label-free antibody detection down to 55 pM target concentration within 5 minutes after sensor functionalization. These results highlight the significant potentials of integrated microsystem for rapid and controlled receptor-transducer interface creation, and the nanoscale VLP-based sensors for fast, accurate and decentralized pathogen detection.