Employing the photothermal effect to improve water quality

Streptomycin sulfate (STS) is an antibiotic used extensively in agriculture that can cause kidney damage if consumed in large amounts. Because STS can make its way into drinking water supplies through agricultural runoff, detecting its presence is crucial for public health. Current detection methods have issues stemming from complicated operation, high cost, or sensitivity to other substances in water.

Zhang et al. developed a method for detecting STS in water using the photothermal effect that is low-cost, highly sensitive, and could be used for real-time detection.

Their method utilizes an Nb₂CT_x MXene material, which has a large specific surface area and many hydrophilic functional groups, increasing the interaction with substances in the water. They paired this material with a few-mode fiber for increased sensitivity to environmental changes.

“In this study, we systematically investigate the properties of Nb₂CTx MXene and how the Nb₂CTx MXene integrated few-mode fiber coupler realizes the photothermal detection of streptomycin sulfate,” said author Yinping Miao.

When irradiated at a specific wavelength, the STS molecules absorb the light energy and convert it to thermal energy, which alters the transmission characteristics of the fiber. The researchers chose a wavelength of 405 nanometers, which allows them to take advantage of additional radiation from natural light for a stronger signal.

The authors hope their method can have an impact on water quality.

“This photothermal sensor eliminates complicated sample processing, making it potentially applicable for real-time food safety, environmental pollutant detection, and disease diagnosis,” said Miao. “We hope that more researchers can learn about the application of photothermal technology in the field of water pollution.”

Source: “Low-concentration antibiotic detection in water based on enhanced photothermal effect,” by Wenjuan Zhang, Yinping Miao, Hongmin Zhang, and Jianquan Yao, Applied Physics Letters (2022). The article can be accessed at https://doi.org/10.1063/5.0098034 .