No abstract

presently, nanotechnology is being foreseen to play an important role in developing analytical assays for the detection of pollutants like mercury (Hg 2+ ). in this study, Kokum fruit mediated silver nanoparticles (AgNPs) were differentially centrifuged to prepare anionic, monodispersed AgNPs to develop a highly sensitive, colorimetric and memristor-based assay for detection of Hg 2+ in water samples. the investigation of the highly selective reaction between Agnps and Hg 2+ using HAADf-SteM images and eDS spectrum indicated the amalgam formation through etching and under potential deposition which resulted in a visible color change from brown to colorless, change in SpR intensity and also change in memristive switching like property of Agnps. the developed colorimetric assay detected Hg 2+ with a limit of detection (LOD) of 6.2 ppb and limit of quantification (LOQ) of 18.9 ppb and, quantitatively recovered Hg 2+ with good accuracy and precision (RSD < 2%). Further, the test of memristive switching like property of AgNPs demonstrated frequency-dependent shrinkage of i-V hysteresis loop indicating memristive switching like property. the test of the sensitivity of Hg 2+ detection was estimated to be 8.7 ppb as the LOD and 26.4 ppb as LOQ. Like the colorimetric assay, the memristor-based assay also recovered Hg 2+ with good accuracy and precision.Residues of mercury (Hg) based organic and inorganic compounds that are used as pesticide or fungicides in agriculture practices can accumulate in aquatic organisms. The residual toxicity of Hg can lead to serious health issues in animals and humans who consume such contaminated aquatic organisms 1 . Coal-burning power plants are the main sources of the pollution of Hg. In addition, other sources from natural and human activities are also known to contribute to Hg pollution 2,3 . It is known that water dissolved ions of mercury (Hg 2+ ) are the most common and stable form of Hg for which point of care detection is necessary to detect and monitor the Hg 2+ levels. Devising selective and sensitive methods for point of care detection of Hg 2+ from clinical diagnostics, household, environment, and industrial waste samples is expected to greatly help protect public health and the environment 4 .Recently, nanotechnology has been foreseen to play a significant and important role in developing the lab-on-chip devices for the detection of environmental pollutants. Metal nanoparticles (NPs) such a silver NPs (AgNPs) and gold NPs (AuNPs) have been demonstrated for their use in heavy metal sensing application 4-8 . Recently, differently synthesized and modified AgNPs and AuNPs were demonstrated for their use in Hg 2+ detection 9-12 . It is noteworthy that all these studies reported the need for functionalization and formation of the complex of a ligand with Hg 2+ for detection. The procedures of surface functionalization of nanomaterials (NMs) are www.nature.com/scientificreports www.nature.com/scientificreports/ somewhat tedious, prone to contamination, require sophisticated instrumen...