Sodium-Entrapped Carbon Nanodots from Silk Wastewater for Combating Multidrug-Resistant Bacteria

Healthcare-associated infection (HAI) is a threat to the healthcare industry due to prolonged hospitalization triggering morbidity, mortality affecting healthcare cost, and resource utilization. There is a continuous impulse to innovate strategies and technologies to prevent HAI. Proper hospital disinfection strategies are clinically pertinent for substantially mitigating the risk of HAIs. Disinfection seeks to eradicate microorganisms on surfaces and equipment, thereby preventing their transmission among patients, healthcare personnel, and others inside the hospital environment. In the present study, a degummed wastewater-derived carbon nanodot (DwCND) was synthesized using silk textile industry sewage with exposure of microwave irradiation. The experimental data indicate that a longer microwave exposure resulted in smaller and uniform particles due to enhanced carbonization and decomposition of precursor influenced by time-dependent cyclization and size reduction. The presence of nitrogen-encompassing functional groups in DwCND facilitates defects in the sp2-hybridized graphitic core. The formation mechanism of sodium-entrapped DwCND is reinforced by cyclization and internalization of sodium ions, closely linked to the microwave irradiation time. High degree of sodium entrapment in DwCND increases the ζ-potential toward positive charge. These oppositely charged DwCND showed bactericidal activity with more than 4 logs drop in bacterial cell viability for both sensitive and multidrug-resistant strains of Gram-positive and Gram-negative organisms. Therefore, DwCND, synthesized through a green facile and scalable process, has potential as an antibacterial surface cleaning agent to prevent multidrug-resistant organisms (MDROs) causing HAIs