In this work, environmentally friendly fluorescent carbon dots (C-dots) were developed for the purpose of thiram identification in the leaves of perilla plants. Powdered plant petals from Hibiscus rosa-sinensis were hydrothermally combined to create C-dots. Analytical techniques, such as scanning electron microscopy, energy dispersive X-ray spectroscopy, high resolution transmission electron microscopy, Raman spectroscopy, ultraviolet spectroscopy, Fourier transmission infrared spectroscopy, and photoluminescence were employed to examine the properties of C-dots. To enhance their functionality, an l-cysteine dopant was added to the C-dots. Since this process produces highly soluble C-dots in water, it is simple, inexpensive, and safe. The excitation process and the size of the blue luminescent C-dots both affect their photoluminescent activity. Furthermore, thiram in aqueous solutions was effectively identified by using the generated C-dots. Additionally, the ImageJ program was used to measure the colors red, green, and blue. High-resolution TEM (HR-TEM) revealed that the l-cysteine-doped carbon dots had an average particle size of 2.208 nm. Additionally, the lattice fringes observed in the HRTEM image showed a d-spacing of around 0.285 nm, which nearly corresponds to the (100) lattice plane of graphitic carbon. A Raman spectrum study was also performed to investigate the relationship between carbon dots and pesticides in the actual samples. In the end, thiram levels in perilla leaves with nondoped and doped C-dots could be distinguished with 100% accuracy using the constructed partial least-squares discriminant analysis machine learning model. The information gathered therefore demonstrated that the synthetic C-dots successfully and efficiently provide rapid and sensitive detection of hazardous pesticides in edible plant products.
Background: India first detected SARS-CoV-2, causal agent of COVID-19 in late January 2020, imported from Wuhan, China. From March 2020 onwards, the importation of cases from countries in the rest of the world followed by seeding of local transmission triggered further outbreaks in India. Methods: We used ARTIC protocol-based tiling amplicon sequencing of SARS-CoV-2 (n=104) from different states of India using a combination of MinION and MinIT sequencing from Oxford Nanopore Technology to understand how introduction and local transmission occurred. Results: The analyses revealed multiple introductions of SARS-CoV-2 genomes, including the A2a cluster from Europe and the USA, A3 cluster from Middle East and A4 cluster (haplotype redefined) from Southeast Asia (Indonesia, Thailand and Malaysia) and Central Asia (Kyrgyzstan). The local transmission and persistence of genomes A4, A2a and A3 was also observed in the studied locations. The most prevalent genomes with patterns of variance (confined in a cluster) remain unclassified, and are here proposed as A4-clade based on its divergence within the A cluster. Conclusions: The viral haplotypes may link their persistence to geo-climatic conditions and host response. Multipronged strategies including molecular surveillance based on real-time viral genomic data is of paramount importance for a timely management of the pandemic.