WO₃ Nanowire-Attached Reduced Graphene Oxide-Based 1D–2D Heterostructures for Near-Infrared Light-Driven Synergistic Photocatalytic and Photothermal Inactivation of Multidrug-Resistant Superbugs

Abstract

The rapid emergence of superbugs which are resistant to existing antibiotics is becoming a huge global threat to public health, which demands the discovery of next-generation antibacterial agents for combating superbugs. Herein, we report the design of a two-dimensional (2D) reduced graphene oxide (r-GO) and one-dimensional (1D) WO3 nanowire-based photothermal–photocatalytic heterostructure for combating multiantibiotic-resistant Salmonella DT104, carbapenem-resistant Enterobacteriaceae Escherichia coli, and methicillin-resistant Staphylococcus aureus superbugs. In the presence of near-infrared (NIR) light, due to the generation of electrons and holes, the WO3-based heterostructure generates reactive oxygen species by photocatalytic reaction from water and oxygen, which kills superbugs. To enhance the photocatalytic superbug killing efficiency, r-GO has been used for suppressing the recombination of the photoinduced electron–hole pairs. Reported data show that NIR light-driven synergistic photocatalytic–photothermal processes can be used for 100% degradation of methylene blue using a heterostructure-based catalyst, and the photodegradation rate for the heterostructure is much better than the literature data for different types of WO3/GO-based nanocomposites. Experimentally, time-dependent antibacterial efficiency data reveals that the heterostructure can destroy 100% superbugs within 30 min of light exposure via a synergistic photothermal and photocatalytic mechanism, whereas the WO3 nanowire can kill around 35% superbugs only via photocatalytic action only and r-GO can kill 25% superbugs via photothermal action even after 30 min of exposure to light. Systematic time-dependent microscopy and spectroscopy studies reveal that the excellent antisuperbug activities for heterostructures are due to membrane damage, ATP, and DNA/RNA breakage. For possible real-life applications, sun light-based superbug inactivation shows 100% inactivation possible within 250 min of light exposure using 12 mg/mL heterostructures. The reported sun light-driven killing of superbugs provides a simple and versatile platform to combat drug-resistant superbugs.

2D Fluorinated Graphene Oxide (FGO)-Polyethyleneimine (PEI) Based 3D Porous Nanoplatform for Effective Removal of Forever Toxic Chemicals, Pharmaceutical Toxins, and Waterborne Pathogens from Environmental Water Samples

“…As we have discussed before, antibiotic contamination is a serious concern for society due to its association with adverse health effects such as the formation of antibiotic-resistant genes. − It can cause several health problems such as immunity decline, genetic defects, and cancer. − As a result, there is an urgent need to design a novel system that has the capability for the detection and removal of antibiotics from environmental samples. − Next, to find out the capturing and separating efficiency of tetracycline and moxifloxacin antibiotics from environmental samples using the FGO-PEI based nanoplatform, we performed the following experiments. Initially, we infected the drinking water samples with tetracycline and moxifloxacin antibiotics selectively and simultaneously.…”

“…As we have discussed before, even in the 21st century, people in many countries in this world are still lacking water that is free from pathogens. − Waterborne pathogens such as Salmonella and Escherichia coli bacteria are the leading causes of waterborne diseases. − As a result, there is an urgent need to design a novel system that has the capability for the removal of waterborne pathogens from environmental samples. − Next, to find out the capturing and separating efficiency of waterborne pathogens such as Salmonella and Escherichia coli bacteria from environmental samples using the FGO-PEI based nanoplatform, we performed the following experiments. Initially, different waterborne pathogens like Salmonella and Escherichia coli were cultured according to the ATCC protocol, as we have reported before. − , Experimental details are reported in the Supporting Information. Once different waterborne pathogens like Salmonella and Escherichia coli grew to 10 5 CFU/ml, we used them for water contamination separation experiments.…”

“…The number of live bacteria was counted in the water samples with a colony counter after 24 h at 37 °C incubation, as we have reported before. − , Details are reported in the Supporting Information.…”

“…Initially, different waterborne pathogens like Salmonella and Escherichia coli were cultured according to the ATCC protocol, as we have reported before. [34][35][36][37][38][39]47 Experimental details are reported in the Supporting Information. Once different waterborne pathogens like Salmonella and Escherichia coli grew to 10 5 CFU/ml, we used them for water contamination separation experiments.…”

“…According to the UN and WHO, every 2 min, a child dies from a water-borne illness in this world. ,− On the other hand, about 7.2 million Americans get sick every year from diseases spread through waterborne pathogens. ,− Because of the low infectious dose, disease transmission is facilitated heavily via the outbreaks of diarrhea, cholera, and typhoid. ,− Recent reports indicate that direct costs of all illnesses caused by waterborne microorganisms are around $3.3 billion/year caused by 17 pathogens. ,− Several antibiotics such as fluoroquinolone, tetracycline, fluoroquinolone, etc., are present in aquatic environments and drinking water. − Recently, several reports indicated that antibiotic residues in water can produce antibiotic-resistant bacteria, which are a serious threat for our society. − To tackle the challenges, scientists are designing a novel adsorbent-based technology that has the potential to improve access to safe drinking water by removing chemical and biological toxins. − …”