Porous silicon on paper-based optical biosensor for diagnostics

There is a critical need for the development of cost-effective, highly sensitive, widely deployable, rapid diagnostic testing systems that can be adapted for detecting a variety of pathogens. This type of testing system can give healthcare providers key information necessary to make educated treatment decisions, and also can facilitate epidemiological studies of disease distribution patterns.

This project investigates whether incorporation of a high surface area porous nanomaterial on a paper substrate can enable a new, highly sensitive, quantitative, and reliable platform for rapid diagnostic testing. The porous nanomaterial serves as the active sensing region that produces a clear optical signal change when signature molecules are selectively captured inside the pores, while the paper substrate is a simple and cost-effective fluid delivery vehicle that enables active transport of a test solution to the porous nanomaterial.

The proposed work will lead to advanced understanding of fluid flow dynamics and molecular attachment in porous nanomaterials integrated with paper as well as advanced knowledge related to interfacing nanomaterials with non-traditional substrate materials. Educationally, this program will expose students to interdisciplinary research at the intersections of optics, materials science, engineering, and chemistry.

A hands-on optical biosensor demonstration kit will be developed and deployed to K-12 students through shareable videos, classroom visits, and on-campus outreach activities.

The goal of this project is to demonstrate a porous silicon-on-paper optical biosensor capable of rapid, accurate, quantitative, and high sensitivity detection of protein biomarkers that will significantly advance the capabilities of rapid diagnostic testing. A comprehensive understanding of the achievable performance metrics, tolerances, and potential limitations of the porous silicon-on-paper optical biosensor platform will be attained.

To accomplish this goal, key advances to realize porous silicon in a lateral flow configuration on paper and understand the fluid flow dynamics and molecular binding kinetics in such a configuration will be achieved. Specifically, this project seeks to: (1) develop a robust approach for integrating nanoscale porous films with paper-based microfluidic substrates; (2) understand molecular transport and binding kinetics in a porous film-on-paper platform as a function of the chemical and physical characteristics of the porous film and species infiltrated in the film; (3) establish the viability of using porous silicon optical thin films in a lateral flow rapid test framework; and (4) validate sensor through detection of SARS-CoV IgM and IgG antibodies.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.