Sensing Antibiotics in Wastewater Using Surface-Enhanced Raman Scattering

Abstract

Rapid and cost-effective detection of antibiotics in wastewater and through wastewater treatment processes is an important first step in developing effective strategies for their removal. Surface-enhanced Raman scattering (SERS) has the potential for label-free, real-time sensing of antibiotic contamination in the environment. This study reports the testing of two gold nanostructures as SERS substrates for the label-free detection of quinoline, a small-molecular-weight antibiotic that is commonly found in wastewater. The results showed that the self-assembled SERS substrate was able to quantify quinoline spiked in wastewater with a lower limit of detection (LoD) of 5.01 ppb. The SERStrate (commercially available SERS substrate with gold nanopillars) had a similar sensitivity for quinoline quantification in pure water (LoD of 1.15 ppb) but did not perform well for quinoline quantification in wastewater (LoD of 97.5 ppm) due to interferences from non-target molecules in the wastewater. Models constructed based on machine learning algorithms could improve the separation and identification of quinoline Raman spectra from those of interference molecules to some degree, but the selectivity of SERS intensification was more critical to achieve the identification and quantification of the target analyte. The results of this study are a proof-of-concept for SERS applications in label-free sensing of environmental contaminants. Further research is warranted to transform the concept into a practical technology for environmental monitoring.

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

“…For the development of the 2D fluorinated graphene oxide and polyethylenimine based 3D porous nanoplatform, we used a three-step synthesis process as reported in Figure . For this purpose, in the first step, we developed water-soluble graphene oxide from graphite using the improved Hummer’s method, as we and others have reported before. − At the end, the yellow mixture was washed with 5% HCl followed by ethanol to remove the metal impurities. The yellow suspension was centrifuged at very high speed several times until the pH was near neutral.…”

“…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.…”

“…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.…”

“…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. − …”

Development of Novel Peptide-Modified Silver Nanoparticle-Based Rapid Biosensors for Detecting Aminoglycoside Antibiotics

“…Among the metal NPs, silver nanoparticles (AgNPs) have been extensively investigated as colorimetric assays and utilized as low-cost nanoprobes for the detection of antibiotics. − Likewise, label-free colorimetric assays based on gold nanoparticles (AuNPs) have been developed for the detection of antibiotics. ,, The aggregation-induced color change and spectral shifts of metal NPs in the presence of target antibiotics enable rapid and sensitive detection. Moreover, besides colorimetric sensing, other types of sensors based on changes in magnetic properties and electrochemical systems have also been demonstrated for the detection of antibiotics. − Additionally, surface-enhanced Raman scattering (SERS) techniques, which rely on the enhancement of Raman signals using metal NPs, have shown great potential for antibiotic detection. − The recent advances in metal NP-based sensing strategies have contributed to the development of practical analytical tools for detecting antibiotics.…”