Rapid and Effective Inactivation of SARS-CoV-2 with a Cationic Conjugated Oligomer with Visible Light: Studies of Antiviral Activity in Solutions and on Supports

This paper presents results of a study of a new cationic oligomer that contains end groups and a chromophore affording inactivation of SARS-CoV-2 by visible light irradiation in solution or as a solid coating on paper wipes and glass fiber filtration substrates. A key finding of this study is that the cationic oligomer with a central thiophene ring and imidazolium charged groups gives outstanding performance in both the killing of E. coli bacterial cells and inactivation of the virus at very short times. Our introduction of cationic N-methyl imidazolium groups enhances the light activation process for both E. coli and SARS-CoV-2 but dampens the killing of the bacteria and eliminates the inactivation of the virus in the dark. For the studies with this oligomer in solution at a concentration of 1 μg/mL and E. coli, we obtain 3 log killing of the bacteria with 10 min of irradiation with LuzChem cool white lights (mimicking indoor illumination). With the oligomer in solution at a concentration of 10 μg/mL, we observe 4 log inactivation (99.99%) in 5 min of irradiation and total inactivation after 10 min. The oligomer is quite active against E. coli on oligomer-coated paper wipes and glass fiber filter supports. The SARS-CoV-2 is also inactivated by oligomer-coated glass fiber filter papers. This study indicates that these oligomer-coated materials may be very useful as wipes and filtration materials.

Highly Effective Inactivation of SARS-CoV-2 by Conjugated Polymers and Oligomers

In the present study, we examined the inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by synthetic conjugated polymers and oligomers developed in our laboratories as antimicrobials for bacteria, fungi, and nonenveloped viruses. The results show highly effective light-induced inactivation with several of these oligomers and polymers including irradiation with near-UV and visible light. In the best case, one oligomer induced a 5-log reduction in pfu/mL within 10 min. In general, the oligomers are more active than the polymers; however, the polymers are active with longer wavelength visible irradiation. Although not studied quantitatively, the results show that in the presence of the agents at concentrations similar to those used in the light studies, there is essentially no dark inactivation of the virus. Because three of the five materials/compounds examined are quaternary ammonium derivatives, this study indicates that conventional quaternary ammonium antimicrobials may not be active against SARS-CoV-2. Our results suggest several applications involving the incorporation of these materials in wipes, sprays, masks, and clothing and other personal protection equipment that can be useful in preventing infections and the spreading of this deadly virus and future outbreaks from similar viruses.

Influence of anode surface chemistry on microbial fuel cell operation

Self-assembled monolayers (SAMs) modified gold anodes are used in single chamber microbial fuel cells for organic removal and electricity generation. Hydrophilic (N(CH3)3(+), OH, COOH) and hydrophobic (CH3) SAMs are examined for their effect on bacterial attachment, current and power output. The different substratum chemistry affects the community composition of the electrochemically active biofilm formed and thus the current and power output. Of the four SAM-modified anodes tested, N(CH3)3(+) results in the shortest start up time (15 days), highest current achieved (225 μA cm(-2)) and highest MFC power density (40 μW cm(-2)), followed by COOH (150 μA cm(-2) and 37 μW cm(-2)) and OH (83 μA cm(-2) and 27 μW cm(-2)) SAMs. Hydrophobic SAM decreases electrochemically active bacteria attachment and anode performance in comparison to hydrophilic SAMs (CH3 modified anodes 7 μA cm(-2) anodic current and 1.2 μW cm(-2) MFC's power density). A consortium of Clostridia and δ-Proteobacteria is found on all the anode surfaces, suggesting a synergistic cooperation under anodic conditions.