Three Waves of Disinfectants to Inactivate Bacteria
- PDF / 439,842 Bytes
- 6 Pages / 432 x 648 pts Page_size
- 63 Downloads / 147 Views
Three Waves of Disinfectants to Inactivate Bacteria Sajid Bashir1,2, James Dinn1, Jingbo Liu1,2 1: Texas A&M University-Kingsville, Kingsville, TX 78363, 361-593-2919 (ph), 361-593-3597 (fax), [email protected], [email protected]; [email protected]; 2: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA ABSTRACT Metallic silver nanoparticles (NPs) have extensively been used in the treatment of disease and purification and heralded the ‘first wave’ of disinfection science, the ‘second wave’ being the nanocomposite of metal-doped TiO2. Recent advances in engineered surfaces have enabled ultrahigh surface area and rapid sterilization via using metal-organic frameworks (MOFs) as the ‘third wave’ disinfectant. MOFs offer the same advantages as colloids but also have ultra high surface area, long term persistence and ultra low doses, applied for water purification. INTRODUCTION§ Semmelweis [1], Pasteur [2] and Lister [3] had demonstrated that microbes could cause disease and that disinfection through chemical means such as with bleach or heat treatment (pasteurization), greatly reduced the transmission of disease [4]. The approach required for “standards” in in vitro “procedures” [5] using specific strains such as Staphylococcus aurerus (ATCC 6538), Pseudomonas aeruginosa (ATCC 15422) using the proscribed dilution method [6], although other microorganism were also evaluated such as Escherichia coli [7]. These protocols firmly established the profound benefits of sterilization [8] and antisepsis (for living matter) [9]. As early as 1900, a review of the literature in a report to the committee on disinfectants identified the following candidates: Formaldehyde, Mercuric chloride, Chloride of lime, Sulphurous acid, Phenol, Copper sulphate, Zinc chloride, Quick lime and boiling of water [10]. Chemical disinfectants are chemicals, which inhibit and inactivate microbes. Since microbes are living biological organism, which may use oxygen as their terminal electron acceptor (aerobic respiration). Small molecules in the absence of oxygen (anaerobic respiration), possible intervention at physical or electrochemical disruption can lead to inhibition of growth and cellular inactivation. The process is achieved chemically are numerous and are classified based on the functional group to which the chemical disinfectant belongs to, or the area of action leading to inhibition e.g. acid, base, detergent, respiration inhibitor and so forth [11]. In this study, three generations of nanodisinfectants have been developed: core-shelled silver Ag NPs (1st generation); Ag-titania (2nd generation); and nanoscaled MOFs (3rd generation). These nanomaterials can be readily prepared using feasible wet-chemistry method [12]. The rationale for using nanomaterials is that their mode of action is different from bleach and may be applicable in circumstances, where microbes have developed a tolerance, particularly when low concentrations of bleach are used for disinfection. EXPERIMENTAL A green chemistry method using natural pr
Data Loading...
