Biologically synthesized PbS nanoparticles for the detection of arsenic in water

Semiconductor nanoparticles have gained importance because of their interesting optical properties. Among these, lead sulfide (PbS) has been extensively studied due to its potential technological applications in field effect transistors, solar cells, photo-voltaics, light emitting diodes, photocatalysis, photo-luminescence, infrared photodetectors, environmental and biological sensors. Hence there is a need to explore cost effective and eco-friendly biological routes for their synthesis. In this paper, biosynthesis of PbS nanoparticles were carried out using endophytic fungi, subsequently detailed characterization was also performed using UV-visible, fluorescence spectrometer, FTIR, SEM, TEM, EDX and XRD. TEM revealed the formation of PbS nanoparticles in typical size range of 35-100 nm. The application of these nanoparticles for detection of arsenic in aqueous solution through their absorbance properties was also dealt. Importantly, the results were demonstrated for detection of 50 ppb As (III) in water without any interference of other selected ions maintained upto 20 ppb under same conditions. Further, the correlation for the bio-sensitivity of PbS nanoparticles based on the quenching effect with arsenic concentrations ranging between 10 and 100 ppb in water samples was deduced.