Heavy metals are a noxious form of pollutants present in soil and water. A new plant-based solar energy driven technology, phytoremediation, emerges as eco-friendly and cost-effective approach to remove heavy metal from various media with the help of hyperaccumulating plant species. This review paper aims to provide information on phytoremediation and its mechanisms for heavy metal removal especially to focus on Cadmium (Cd) metal and highlights the role of various hyperaccumulating plants for Cd metal remediation in soil and water. It complies various field case studies which play the important role in understanding the Cd removal through various plants. Additionally, it pinpoints several sources and the effects of Cd and other technologies used for Cd remediation. This paper provides the recent development in mechanisms of Cd hyperaccumulation by different plants, in order to motivate further research in this field.

We present a novel immunoassay format utilizing the catalytic properties of gold nanoparticles in the luminol–silver nitrate–gold nanoparticle based chemiluminescence (CL) system for the detection of widely used herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Highly sensitive anti-2,4-D antibody was produced and conjugated with gold nanoparticles of various sizes. In the present assay format, employing a competitive inhibition approach, a well-characterized hapten–protein conjugate (2,4-D–BSA) was used to coat the microtiter plates. The analyte (2,4-D) was pre-incubated with anti-2,4-D antibody labeled with gold nanoparticles and added to each well of the microtiter plate. The gold label triggered the reaction between luminol and silver nitrate generating a luminescence signal at 425 nm. Under the optimized conditions, the CL based immunoassay showed the detection limit of 2,4-D in standard water samples around 3 ng mL⁻¹. The CL based immunoassay format, based on gold nanoparticles as a catalyst, could be used as a fast screening methodology (<30 min) for pesticide detection.

A one-step homogeneous colorimetric immunoassay format coupled with zeta potential measurements for determination of specific diabetic biomarker glycated hemoglobin (HbA1c) using functionalised gold nanoparticles as bioprobes is reported. The assay exhibited an excellent sensitivity based on absorbance and zeta potential measurements showing the dynamic response range from 0.001–0.004 mg mL⁻¹ for HbA1c with a detection limit of 0.0015 mg mL⁻¹.

To assess the current epidemic trend of COVID-19/SARS-CoV-2 in India, the epidemic dynamics of COVID-19 cases in India in terms of Case Fatality Rate (CFR), Case Recovery Rate (CRR) and Mortality rate (MR) COVID-19 have been evaluated during Lockdown-1. The analysis includes (i) epidemic curve of Covid-19 cases (ii) demographic analysis (iii) calculation of the CFR and CRR by different methods (iv) calculation of MR (v) Geo-temporal analysis (vi) epidemiological transmission factor (vii) evaluation of the effects and impact of infection, prevention and control in India. A total of 10,815 COVID-19 confirmed cases have been reported in 31 states/union territories as of April 14, 2020 with 9272 active cases (85.73%), 1190 cured/discharged (11%), and 353 deaths (3.23%). Among confirmed cases, most cases (59%) are aged 20–49 which is working age in India and 76% cases are reported for men. The median age of Indian COVID-19 patients found to be 39. As of April 14, the CFR per total cases in India is 3.32% and per closed cases is 23.27%. The CRR per total cases in India is 11.00% and per closed cases is 76.72%, which indicates that the recovery rate of COVID-19 is more than the fatality rate in India. The prevention and control measures taken by the state and central governments at all levels and measure of maintenance of social distancing by people have resulted in effective curbing in the COVID-19 transmission in India.