Cigarette butt waste derived activated carbon incorporated silver nanoparticle (AC-Ag): Effective nanocomposite for anti-bacterial and anti-larval activity in wastewater remediation

[Display omitted] •Hazardous waste (cigarettes butts) was utilized for the synthesis of AC-Ag nanocomposite.•AC-Ag nanocomposite was confirmed by UV–vis, XRD, FTIR, HRTEM-EDAX and BET.•AC-Ag nanocomposite were extremely toxic against bacterial pathogens and mosquito vectors at lethal doses. The thread of resistance development among insects and bacterial pathogens has created the need for developing highly effective and safe drugs. In this research, we studied the toxicity of AC-Ag nanocomposite prepared from cigarette butts (CBs) on key mosquito vectors, Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus, and gram-negative, gram-positive bacteria respectively. They were extremely toxic against IInd and IVth instar larvae of An. stephensi, Ae.aegypti and Cx. quinquefasciatus, notably, with LC50 of 5.892 (IInd instar), 8.701 (IVth instar), 8.657 (IInd instar), 13.324 (IVth instar), and 13.448 (IInd instar), 17.248 μg/ml (IVth instar) on An. stephensi, Ae. aegypti and Cx. quinquefasciatus. In antibacterial assays, low doses of the CBs derived AC-Ag nanocomposite inhibited the growth of Escherichia coli and Staphylococcus aureus. The surface damage, ROS production and protein leakage are the antibacterial mechanisms of AC-Ag. This study proved that a CBs derived AC-Ag nanocomposite could be given at ultra-low doses to reduce the bacterial and mosquito larval population.