Microplastics in packaged water, community stored water, groundwater, and surface water in rivers of Tamil Nadu after the COVID-19 pandemic outbreak.

The increased load of plastic in waste streams after the COVID-19 pandemic outbreak has increased the possibility of microplastics (MPs) contamination channelling through the rivers and infiltrating the aquatic ecosystems. MPs in packaged water, community-stored water, groundwater, and surface water of Kaveri River (KR), Thamirabarani River (TR), Adyar River (AR), and Cooum River (CR) in Tamil Nadu were therefore investigated about 2 years after the COVID-19 pandemic outbreak. Using µFTIR and µRaman spectroscopy, polyamide, polypropylene, polyethylene, ethylene vinyl alcohol copolymer resin, and polyvinyl chloride were identified as the primary polymer types. The average number of MPs was 2.15 ± 1.9 MP/L, 1.1 ± 0.99 MP/L, 5.25 ± 1.15 MP/L, and 4 ± 2.65 MP/L in KR, TR, AR, and CR, respectively, and 1.75 ± 1.26 MP/L in groundwater, and 2.33 ± 1.52 MP/L in community stored water. Only LDPE was detected in recycled plastic-made drinking water bottles. More than 50% of MPs were found to be of size less than 1 mm, with fibrous MPs being the prevalent type, and a notable prevalence of blue-coloured microplastics in all the sample types. The Pollution Load Index (PLI) was >1 in all the rivers. Toxicity rating based on the polymer risk index (PORI) categorized AR and TR at medium risk (category II), compared to KR and CR at considerable risk (category III). Overall pollution risk index (PRI) followed a decreasing trend with CR > AR > KR > TR of considerable to low-risk category. Ecological risk assessment indicates a negligible risk to freshwater biota, except for four sites in the middle and lower stretches of Adyar River (AR - 2, AR - 4) and upper and lower stretches of Cooum River (CR - 1, CR - 3), located adjacent to direct sewer outlets, and one location in the lower stretch of Kaveri River (KR - 9), known for fishing and tourist activities.

Optical Nanobiosensor-Based Point-of-Care Testing for Cardiovascular Disease Biomarkers.

Cardiovascular disease is a global health threat, and detecting cardiac biomarkers is essential for early-stage diagnosis and personalized treatment. Traditional approaches have limitations, but optical nanobiosensors offer rapid, highly selective, and sensitive detection. Optical nanobiosensors generate biosignals that transfer light signals while analytes bind with the bioreceptors. Optical nanobiosensors have advantages such as ease of monitoring, low cost, a wide detection range, and high sensitivity without any interference. An optical nanobiosensor platform is a promising approach for point-of-care cardiac biomarker detection with a low detection limit. This review mainly focuses on the detection of cardiovascular disease biomarkers based on various optical nanobiosensor approaches that have been reported during the last five years, and we have categorized them based on optical signal readouts. A detailed discussion of the classification of cardiovascular disease biomarkers, design strategies of optical biosensors, types of optically active nanomaterials, types of bioreceptors, functionalization techniques, various assay types, and sensing mechanisms is presented. Then, we summarize the optical signaling readout-based various nanobiosensors systems for the detection of cardiovascular disease biomarkers. Finally, we summarize and conclude with the recent development of point-of-care testing (PoCT) for cardiovascular disease biomarkers used in various optical readout techniques.