ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Photoinactivation of Escherichia coli and Staphylococcus aureus using Porphyrin-CuInS₂/ZnS quantum dot conjugates immobilized on Mesoporous Silica

Knowledge Siyabonga Ndlovu, Khomotso Chokoe, Tracy Masebe, Kutloano Edward Sekhosana, Makwena Justice Moloto, and Muthumuni Managa

Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology (CSET), University of South Africa, Johannesburg, South Africa

E-mail: managme@unisa.ac.za

Received: 4 January 2024  Accepted: 29 March 2024

Abstract:

Bacterial pathogens remain major contributors to illnesses as they have developed several resistance mechanisms against standard treatments. Innovative porphyrin-quantum dots conjugated materials have great potential in addressing the limitations in the current disinfection methods. The antimicrobial activity of metal-free and In(III) derivative of 4-(15-(4-boronophenyl)-10,20-diphenylporphyrin-5-yl)benzoic acid conjugated to CuInS₂/ZnS quantum dots is investigated in this study at laboratory-scale experiments under controllable conditions. The conjugate was also immobilized on mesoporous silica for recovery and reusability purposes. Findings of the study were driven by antimicrobial photodynamic inactivation (aPDI) in the presence of a porphyrin and quantum dots. POR(In)-CIS/ZnS QDs-Silica was the best performing conjugate with a singlet quantum yield (Φ_Δ) of 0.72 and a log reduction of 9.38 and 9.76 against Escherichia coli and S. aureus, respectively.

Keywords: E. coli; S. aureus; Porphyrin; Quantum dots; Antimicrobial photodynamic inactivation; Mesoporous silica

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-024-03447-w

Chemical Papers 78 (8) 4991–5004 (2024)