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This paper focuses on the use of Cyclea peltataleaf extract for green synthesis of silver nanoparticles (CPL-AgNPs) post-optimization by one variable at a time (OVAT) approach for nonlinear optics application. The leaf extract of Cyclea peltata(10% w/v) and AgNO3(1 mM) was used for the synthesis of silver nanoparticles (CPL-AgNPs). Reactions conditions like CPL extract concentration, salt concentration, temperature, pH, RPM, and time for synthesis were optimized by using OVAT approach. A UV-visible spectroscopic investigation confirmed the biosynthesis of CPL-AgNPs at 420 nm. Field emission scanning electron microscope (FESEM) confirmed the spherical monodispersed nanoparticles in the range of 30–50 nm and EDAX confirmed the purity of the sample. FTIR confirmed the capping of nanoparticles by plant phytochemicals. The synthesized CPL-AgNPs were evaluated for nonlinear optical properties using the Z-scan technique at 532 nm with a CW laser. Strong nonlinear absorption by the nanoparticles in the range of 2.85 × 10−2cm/W was observed. Moreover, CPL-AgNPs display superior optical limitations.

•Kleibsiella pneumoniae Kpn555 tolerates 900 mg/L lead.•SEM and TEM studies revealed surface deposition and bioaccumulation of lead.•Surface deposition mediated by EPS produced in response to lead stress, characterised as glycolipid with protein moieties.•Maximum biosorption ability of EPS – 475 mg/g.•Ability of lead bioaccumulation is plasmid mediated.

Of the seventeen samples of human adipose tissue and seven samples of human liver analysed for PCB, all were found to contain PCB. The adipose tissue showed mean PCB concentration of 0.920 ppm and the PCB contamination ranged from 0.206-2.843 ppm. On the other hand, liver samples were found to contain mean PCB concentrations of 0.403 ppm and the contamination of PCB ranged from 0.111-0.747 ppm. The analysis of PCB was done on a gas Chromatograph equipped with electron capture detector. The extraction of samples was done with hexane followed by clean up on a silica gel column.

Rapid synthesis of nanoparticles using biological materials is gaining importance in recent years as it is eco-friendly and cost-effective with a lesser environmental burden. In this paper, we report the biosynthesis of alloy nanoparticle of iron and copper (FeCuNPs) from its precursor salts ferrous sulphate and copper sulphate using extract of waste silkworm cocoon, which will provide value addition to the byproduct of the silk industry. Proteins present in cocoon extract helped in reducing the precursor metal salt to nanoparticles by coating around the nanoparticles, thereby, increasing their stability, which was confirmed by FTIR. Characterisation of FeCuNPs was done by techniques like UV-visible spectrophotometry, particle size, and zeta potential and XRD. The synthesised FeCuNPs were tested for their antimicrobial effect against bacterial pathogens (Bacillusspp., E. coli, P. aeruginosa) and fungal pathogens like Aspergillus flavus, Aspergillus niger, and Fusariumspp. using known antibiotics as control. Application of biosynthesised FeCuNPs on mortar showed significant antimicrobial activity, hence these nanoparticles can be widely utilised as protective agents in cement mortars for inhibiting the growth of pathogens of environmental concern thereby avoiding early ageing of the mortar.

Twenty-six human whole milk samples were analysed for the presence of PCBs. 96% of the samples were found to contain Aroclor 1260 type PCBs, whose concentration varied from 0.0-1.413 ppm and a mean concentration of 0.409 ppm. The maximum number of samples were found to contain PCB in the range of 0.1-0.5 ppm with 61 % incidence.