Fiber-assisted emulsification microextraction coupled with gas chromatography–mass spectrometry for the determination of aromatic amines in aqueous samples

A novel TiO2-modified THPP-BCP composite optical waveguide sensor for the determination of ethylenediamine at ppb level

Composite thin films OWG sensors show higher sensitivity than single film-based OWG sensors, making them particularly useful in the detection of trace gases. In this work, we developed a new tetra hydroxyphenyl porphyrin (THPP)-bromocresol purple (BCP)/TiO2 gel composite film-based OWG (THPP-BCP/TiO2-OWG) sensor for identifying ethylenediamine (EDA) gas. The fabricated sensor was characterized using ultraviolet and infrared spectroscopy and atomic force microscopy. The test result shows that the response of the THPP-BCP/TiO2-OWG composite film sensor to analytes was 3-4 times higher than that of the single film THPP-OWG sensor. The THPP-BCP/TiO2-OWG sensor exhibited excellent selectivity and remarkable response to EDA gas at a concentration of < 1 ppb at room temperature, with fast response (1 s) and recovery (3 s) times. The high refractive index TiO2 film contributes to OWG's sensitivity, while the THPP and BCP's sensitivity to bases further increased the sensor's response to EDA gas. The combination of THPP-BCP thin film and TiO2 gel film provides a powerful platform for OWG sensors that are highly sensitive, specific, and stable in the detection of trace gases.

Recent advances of environmental pollutants detection via paper-based sensing strategy

Paper has become one of the most promising substrates for building low-cost and powerful sensing platforms due to its self-pumping ability and compatibility with multiple patterning methods. Paper-based sensors have been greatly developed in the field of environmental monitoring. In this review, we introduced the research and application of paper-based sensors in environmental monitoring, focusing on the deposition and patterning methods of building paper-based sensors, and summarized the applications of detecting environmental pollutants, including metal ions, anions, explosives, neurotoxins, volatile organic compounds, and small molecules. In addition, the development prospects and challenges of promoting paper-based sensors are also discussed. The current review will provide references for the construction of portable paper-based sensors, and has implications for the field of on-site real-time detection of the environment.