Colorimetric optical chemosensor of toxic metal ion (Hg²⁺) and biological activity using green synthesized AgNPs

Abstract

In this paper, we have reported the green synthesis of silver nanoparticles (AgNPs) using silver nitrate and Ficus carica (fig) stem extract at room temperature. We have also explored the effect of volume of extract (1-3 ml) on the formation of AgNPs using various analytical techniques such as Fouriertransform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), and energy-dispersive X-ray analyzer (EDX). The formations of AgNPs were monitored by ultraviolet-visible spectrophotometer as well as from color change through the naked eye. The absorption peaks appear between 442 and 455 nm, confirming to surface plasmon resonance (SPR) of AgNPs. It is clear from the FTIR results that the biologically active compounds present in the extract act as capping and reducing agents for AgNPs creation. Electron microscopy results show that by increasing the concentration of extract, the morphology and size of AgNPs changed due to the presence of more phenolic group. The green synthesized AgNPs have been sequentially employed for the selective and sensitive detection of toxic metal ion (Hg 2+) in aqueous medium and antimicrobial activity against all tested microbes including five gram negative and two gram positive. Furthermore, the brown color of green synthesized AgNPs turned into colorless with Hg 2+ ion by naked eye response and the limit of detection was 1.06 µM. Figure (A) represents the UV-visible spectra of AgNPs with different concentrations of Hg 2+ (0.1-10 µM) in aqueous solution and inset shows the variation of the absorbance of AgNPs solution as a function of Hg 2+ ion concentration.

Schiff Bases and Multidentate Organic Compounds as Fluorescent Sensors of Al3+: Photophysical, Fluorescent Bioimaging and the Mechanisms

“…This mechanism can occur intramolecularly when the same molecule contains both donor and proton acceptor groups in proximity, like ‐OH and C=N, respectively [39] . The proton can be transferred directly from the acid to the basic site in the S 0 or in the S 1 state and take place in the so‐called Ground State Intramolecular Proton Transfer (GSIPT) [39,179] . or Excited‐State Intramolecular Proton Transfer (ESIPT), [34,179, 180] respectively.…”

“…[31,173] These spectral changes and non-radiative deactivation of the excited state, by MLCT transition, allowed the sensing of metal ions in several complex matrices through colorimetric methods or CHEQ effect, respectively. [25,28,31,[173][174][175][176][177][178][179][180][181][182][183][184] As these mechanisms also depend on a careful turning of the structure and electronic properties, the theoretical calculations have been a powerful tool to understand and predict these transduction mechanisms in chemosensors based on Schiff bases.…”

“…[39] The proton can be transferred directly from the acid to the basic site in the S 0 or in the S 1 state and take place in the so-called Ground State Intramolecular Proton Transfer (GSIPT). [39,179] or Excited-State Intramolecular Proton Transfer (ESIPT), [34,179,180] respectively. These mechanisms play an important role in many biological and photochemical reactions allowing several analytes like cations, [181] anion, [182] or medium (protic or aprotic) [183] to be detected from the inhibition or activation of these transduction mechanisms.…”

A Simple Method for Developing a Hand‐Drawn Paper‐Based Sensor for Mercury; Using Green Synthesized Silver Nanoparticles and Smartphone as a Hand‐Held‐Device for Colorimetric Assay

“…No data regarding the real field analysis on regular drinking water were reported. [ 56 ] Also, Ismail's group proposed a paper‐based AgNPs probe for the recognition of Hg (II), Cr (VI), and ammonia in solution. They found a linear detection range of 50 × 10 −3 to 50 × 10 −6 m for Hg 2+ ion.…”

Green Synthesis and Applications of Silver Nanoparticles: A Systematic Review

“…The width and position of the SPR peak depend primarily on the size and shape of the particles. 198,199 These properties allow AgNPs to be used in sensing detection such as peptide laser desorption/ionization mass spectrometry for detection of DNA sequences, 200,201 histidine colorimetric sensors, 202 and measurement of human plasma fibrinogen. 203 These properties allow AgNPs to be used in detection applications such as DNA sequence detection, laser desorption/ionization mass spectrometry of histidine peptide colorimeter sensors, and Somuyusowon measurement of human plasma.…”