Microplastics: Challenges, toxicity, spectroscopic and real-time detection methods

Plastics are in high demand for various uses worldwide because of their low cost, versatility, lightweight, low density, flexibility, high strength, and durability. An increase in single-use plastics and ineffective solid waste disposal and recycling strategies have resulted in a global microplastic (MP) pollution epidemic, with negative implications for the ecosystem and public health safety. Analytical methods, including thermogravimetry and chromatography, have been developed to detect MPs. Nevertheless, molecular spectroscopy methods such as Near Infrared (NIR), Fourier Transform Infrared (FTIR), Raman, and fluorescence spectroscopy for MP analysis have gained attention in recent years due to their rapidity, low cost, accuracy, and portability of spectrometers. This review article provides in-depth coverage of the survey of current literature on the challenges, toxicity, sample pretreatment, and spectroscopic (Fluorescence, Raman, FTIR) and real-time (satellite imagery, unmanned aerial vehicles, and aquatic drone technology) microplastic detection methods. Machine learning, micro-hyperspectral imaging, and chemometrics approach to microplastic detections are discussed. The challenges, future directions, and prospects for decreasing global MP pollution and their analysis are discussed.