Nora Savage
$187,858
Yizhi J Tao
William Marsh Rice University
Texas
Engineering (ENG)
The virus that causes COVID-19 (i.e., SARS-CoV-2) has been found in air ducts, suggesting that it could spread around buildings via air conditioning systems. SARS-CoV-2 is also shed in stool despite patients testing negative, and thus it may reach wastewater treatment plants, where it could survive for days and be aerosolized or discharged in the effluent. In fact, there are reports that SARS-CoV-2 may spread through bathroom pipes. Although coronaviruses can be inactivated by some conventional water treatment processes, there is an urgent need for more precise viral disinfection approaches that are fast, efficient and reliable under realistic scenarios. The objective of this project is to develop a novel approach for selective adsorption and photocatalytic disinfection (i.e., trap-and-zap) of SARS-CoV-2 and other pathogenic coronaviruses. This would result in a chemical-free technology (thus avoiding harmful disinfection byproducts) with unprecedented precision and reliable efficiency to inactivate coronavirus. The driving hypothesis is that molecular imprinting of graphitic carbon nitride with common coronavirus attachment factors will enable selective virus adsorption near reactive sites, resulting in reliably high disinfection. Whereas enhancing the capacity and resiliency of wastewater disinfection and hospital air sterilization systems to protect public health against emerging infectious diseases has significant intrinsic merit, the benefits of this project are much broader. This project will enhance surface recognition of various types of coronavirus (e.g., those causing COVID-19, MERS and SARS), which will inform efforts to concentrate them and improve both precision separation (e.g., by superior sorbents) and detection limits of sensors that can be used in diagnostics and surveillance efforts. Project results will be integrated into various courses, including the NanoEnvironmental Engineering for Teachers (NEET) course at Rice, which enrolls 15 teachers that reach over 3,300 high school students annually. This course recently expanded to Arizona State University and is also being expanded to the University of Texas at El Paso, thereby ensuring wide dissemination of this “trap-and-zap” approach to STEM teachers.This project builds on a recently published, nanotechnology-enabled “trap-and-zap” approach (enhanced by molecular imprinting), to selectively adsorb antibiotic resistant genes and concentrate them near photocatalytic sites for efficient degradation (doi.org/10.1021/acs.est.9b06926). This approach will be modified to target SARS-CoV-2 and other coronavirus by imprinting molecules involved in virus attachment such as sialic acids, heparin sulfate proteoglycan, and angiotensin-converting enzyme–related carboxypeptidase (ACE2)-associated peptides onto the graphitic carbon nitride photocatalysts. When the imprinted molecule is removed (e.g., by acid washing), it leaves behind a target-specific cavity that enables selective adsorption and photocatalytic inactivation with minimum interference by background water constituents. Low pathogenic coronavirus HCoV-NL63 (which, similarly to SARS-CoV 2, is enveloped with an S spike protein and uses the same cell surface molecule ACE2 as host receptor) will be used to assess adsorption kinetics and selectivity of molecularly imprinted-gC3N4 in the presence of competing proteins (such as bovine serum albumin) and bacteriophage MS2. Inactivation efficiency will be assessed by quantifying residual viable virus concentrations, using the plaque assay with Avicel overlay. Specific tasks include to (1) select a model coronavirus (e.g., HCoV-NL63) and attachment factors for molecular imprinting; (2) prepare homogenous, stable, biomolecular materials for imprinting; (3) synthesize the molecularly-imprinted catalyst; (4) characterize adsorption kinetics and selectivity of target coronavirus particles to the molecularly-imprinted catalyst; (5) benchmark virus inactivation efficiency of the molecularly imprinted -coated catalyst against traditional disinfection methods (chlorination, ultraviolet irradiation) under realistic conditions; and (6) assess durability and reuse potential of the molecularly imprinted catalyst Project results will be integrated into various courses, including the NanoEnvironmental Engineering for Teachers (NEET) course at Rice, which enrolls 15 teachers that reach over 3,300 high school students annually. This course recently expanded to Arizona State University and is also being expanded to the University of Texas at El Paso, thereby ensuring wide dissemination of this “trap-and-zap” approach to STEM teachers.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.